View Filing Data

Print Document View Excel Document

Document and Entity Information	12 Months Ended
Document and Entity Information	Dec. 31, 2018 shares
Document Information [Line Items]
Document Type	20-F
Amendment Flag	false
Document Period End Date	Dec. 31, 2018
Document Fiscal Year Focus	2018
Document Fiscal Period Focus	FY
Trading Symbol	VNET
Entity Registrant Name	21VIANET GROUP, INC.
Entity Central Index Key	0001508475
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Filer Category	Accelerated Filer
Entity Shell Company	false
Entity Emerging Growth Company	false
Class A Ordinary Shares
Document Information [Line Items]
Entity Common Stock, Shares Outstanding	499,706,628
Class B Ordinary Shares
Document Information [Line Items]
Entity Common Stock, Shares Outstanding	174,649,638

Consolidated Balance Sheets ¥ in Thousands, $ in Thousands	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)
Current assets:
Cash and cash equivalents	$ 343,038	¥ 2,358,556	¥ 1,949,631
Restricted cash	38,574	265,214	242,494
Accounts and notes receivable (net of allowance for doubtful debt of RMB73,656 and RMB70,970 (US$10,322) as of December 31, 2017 and 2018, respectively)	76,257	524,305	455,811
Short-term investments	35,636	245,014	548,890
Inventories	267	1,834	710
Prepaid expenses and other current assets	168,385	1,157,740	933,750
Amounts due from related parties	18,245	125,446	114,256
Total current assets	680,402	4,678,109	4,245,542
Non-current assets:
Property and equipment, net	586,320	4,031,242	3,319,424
Intangible assets, net	51,678	355,313	401,115
Land use rights, net	21,452	147,493	163,671
Goodwill	143,921	989,530	989,530
Restricted cash	5,418	37,251	3,344
Deferred tax assets	23,190	159,441	172,818
Long-term investments	79,168	544,323	510,926
Amounts due from related parties	5,007	34,424	20,210
Other non-current assets	25,248	173,591	81,581
Total non-current assets	941,402	6,472,608	5,662,619
Total assets	1,621,804	11,150,717	9,908,161
Current liabilities:
Short-term bank borrowings (including short-term bank borrowings of the Consolidated VIEs without recourse to the primary beneficiaries of RMB50,000 and RMB50,000 (US$7,272) as of December 31, 2017 and 2018, respectively)	7,272	50,000	50,000
Accounts and notes payable (including accounts and notes payable of the Consolidated VIEs without recourse to the primary beneficiaries of RMB157,970 and RMB258,048 (US$37,532) as of December 31, 2017 and 2018, respectively)	56,652	389,508	252,892
Accrued expenses and other payables (including accrued expenses and other payables of the Consolidated VIEs without recourse to the primary beneficiaries of RMB368,190 and RMB392,619 (US$57,104) as of December 31, 2017 and 2018, respectively)	95,894	659,320	657,133
Advances from customers (including advances from customers of the Consolidated VIEs without recourse to the primary beneficiaries of RMB403,244 and RMB670,037 (US$97,453) as of December 31, 2017 and 2018, respectively)	97,453	670,037	403,244
Deferred revenue (including deferred revenue of the Consolidated VIEs without recourse to the primary beneficiaries of RMB49,699 and RMB51,026 (US$7,421) as of December 31, 2017 and 2018, respectively)	8,400	57,754	55,753
Income taxes payable (including income taxes payable of the Consolidated VIEs without recourse to the primary beneficiaries of RMB7,400 and RMB8,519 (US$1,239) as of December 31, 2017 and 2018, respectively)	1,907	13,111	13,309
Amounts due to related parties (including amounts due to related parties-current of the Consolidated VIEs without recourse to the primary beneficiaries of RMB16,053 and RMB51,763 (US$7,529) as of December 31, 2017 and 2018, respectively)	7,611	52,328	55,675
Current portion of long-term bank borrowings (including current portion of long-term bank borrowings of the Consolidated VIEs without recourse to the primary beneficiaries of RMB70,289 and RMB75,284 (US$10,950) as of December 31, 2017 and 2018, respectively)	10,950	75,284	70,289
Current portion of capital lease obligations (including current portion of capital lease obligations of the Consolidated VIEs without recourse to the primary beneficiaries of RMB201,315 and RMB219,695 (US$31,953) as of December 31, 2017 and 2018, respectively)	31,953	219,695	201,315
Deferred government grants (including deferred government grants of the Consolidated VIEs without recourse to the primary beneficiaries of RMB4,574 and RMB4,173 (US$607) as of December 31, 2017 and 2018, respectively)	607	4,173	4,574
Total current liabilities	318,699	2,191,210	1,764,184
Non-current liabilities:
Non-current portion of long term bank borrowings (including long-term bank borrowings of the Consolidated VIEs without recourse to the primary beneficiaries of RMB187,638 and RMB112,000 (US$16,290) as of December 31, 2017 and 2018, respectively)	16,290	112,000	187,638
Bonds payable (including bonds payable of the Consolidated VIEs without recourse to the primary beneficiaries of nil and nil as of December 31, 2017 and 2018, respectively)	296,391	2,037,836	1,929,208
Non-current portion of capital lease obligations (including non-current portion of capital lease obligations of the Consolidated VIEs without recourse to the primary beneficiaries of RMB687,176 and RMB852,287 (US$123,960) as of December 31, 2017 and 2018, respectively)	111,409	765,993	600,882
Unrecognized tax benefits (including unrecognized tax benefits of the Consolidated VIEs without recourse to the primary beneficiaries of RMB13,225 and RMB4,938 (US$718) as of December 31, 2017 and 2018, respectively)	971	6,677	16,511
Deferred tax liabilities (including deferred tax liabilities of the Consolidated VIEs without recourse to the primary beneficiaries of RMB109,339 and RMB84,568 (US$12,300) as of December 31, 2017 and 2018, respectively)	22,939	157,720	190,873
Deferred government grants (including deferred government grants of the Consolidated VIEs without recourse to the primary beneficiaries of RMB17,861 and RMB11,619 (US$1,690) as of December 31, 2017 and 2018, respectively)	1,690	11,619	17,861
Amounts due to related parties (including amounts due to related parties of the consolidated VIEs without resource to the primary beneficiaries of nil and RMB 504,478 (US$73,373) as of December 31, 2017 and 2018, respectively)	73,373	504,478
Total non-current liabilities	523,063	3,596,323	2,942,973
Total liabilities	841,762	5,787,533	4,707,157
Commitments and contingencies
Shareholders' equity:
Additional paid-in capital	1,329,575	9,141,494	8,980,407
Accumulated other comprehensive (loss) income	12,505	85,979	(2,673)
Statutory reserves	6,167	42,403	38,736
Accumulated deficit	(558,219)	(3,838,032)	(3,629,300)
Treasury stock	(49,114)	(337,683)	(337,683)
Total 21Vianet Group, Inc. shareholders' equity	740,921	5,094,207	5,049,533
Noncontrolling interest	39,121	268,977	151,471
Total shareholders' equity	780,042	5,363,184	5,201,004
Total liabilities and shareholders' equity	1,621,804	11,150,717	9,908,161
Class A Ordinary Shares
Shareholders' equity:
Ordinary shares	5	34	34
Class B Ordinary Shares
Shareholders' equity:
Ordinary shares	$ 2	¥ 12	¥ 12

Consolidated Balance Sheets (Parenthetical) ¥ in Thousands, $ in Thousands	Dec. 31, 2018 USD ($) $ / shares shares	Dec. 31, 2018 CNY (¥) shares	Dec. 31, 2017 CNY (¥) shares
Accounts and notes receivable, allowance for doubtful accounts	$ 10,322	¥ 70,970	¥ 73,656
Short-term bank and other borrowings of the Consolidated VIEs without recourse to the primary beneficiaries	7,272	50,000	50,000
Accounts and notes payable of the Consolidated VIEs without recourse to the primary beneficiaries	56,652	389,508	252,892
Accrued expenses and other payables of the Consolidated VIEs without recourse to the primary beneficiaries	95,894	659,320	657,133
Advance from customers of the Consolidated VIEs without recourse to the primary beneficiaries	97,453	670,037	403,244
Deferred revenue of the Consolidated VIEs without recourse to the primary beneficiaries	8,400	57,754	55,753
Income tax payables of the Consolidated VIEs without recourse to the primary beneficiaries	1,907	13,111	13,309
Amounts due to related parties of the consolidated VIEs without resource to the primary beneficiaries	7,611	52,328	55,675
Current portion of long term bank and other borrowings of the Consolidated VIEs without recourse to the primary beneficiaries	10,950	75,284	70,289
Current portion of capital lease obligations of the Consolidated VIEs without recourse to the primary beneficiaries.	31,953	219,695	201,315
Deferred government grants of the Consolidated VIEs without recourse to the primary beneficiaries	607	4,173	4,574
Long-term bank borrowings of the Consolidated VIEs without recourse to the primary beneficiaries	16,290	112,000	187,638
Bonds payable Consolidated VIEs without recourse to the primary beneficiaries.	296,391	2,037,836	1,929,208
Non-current portion of capital lease obligations of the Consolidated VIEs without recourse to the primary beneficiaries	111,409	765,993	600,882
Unrecognized tax benefits of the Consolidated VIEs without recourse to the primary beneficiaries	971	6,677	16,511
Deferred tax liabilities of the Consolidated VIEs without recourse to the primary beneficiaries	22,939	157,720	190,873
Deferred government grants of the Consolidated VIEs without recourse to the primary beneficiaries	1,690	11,619	17,861
Amounts due to related parties related parties of the consolidated VIEs without resource to the primary beneficiaries	73,373	504,478
Variable Interest Entity, Primary Beneficiary
Short-term bank and other borrowings of the Consolidated VIEs without recourse to the primary beneficiaries	7,272	50,000	50,000
Accounts and notes payable of the Consolidated VIEs without recourse to the primary beneficiaries	37,532	258,048	157,970
Accrued expenses and other payables of the Consolidated VIEs without recourse to the primary beneficiaries	57,104	392,619	368,190
Advance from customers of the Consolidated VIEs without recourse to the primary beneficiaries	97,453	670,037	403,244
Deferred revenue of the Consolidated VIEs without recourse to the primary beneficiaries	7,421	51,026	49,699
Income tax payables of the Consolidated VIEs without recourse to the primary beneficiaries	1,239	8,519	7,400
Amounts due to related parties of the consolidated VIEs without resource to the primary beneficiaries	7,529	51,763	16,053
Current portion of long term bank and other borrowings of the Consolidated VIEs without recourse to the primary beneficiaries	10,950	75,284	70,289
Current portion of capital lease obligations of the Consolidated VIEs without recourse to the primary beneficiaries.	31,953	219,695	201,315
Deferred government grants of the Consolidated VIEs without recourse to the primary beneficiaries	607	4,173	4,574
Long-term bank borrowings of the Consolidated VIEs without recourse to the primary beneficiaries	16,290	112,000	187,638
Bonds payable Consolidated VIEs without recourse to the primary beneficiaries.	0	0	0
Non-current portion of capital lease obligations of the Consolidated VIEs without recourse to the primary beneficiaries	123,960	852,287	687,176
Unrecognized tax benefits of the Consolidated VIEs without recourse to the primary beneficiaries	718	4,938	13,225
Deferred tax liabilities of the Consolidated VIEs without recourse to the primary beneficiaries	12,300	84,568	109,339
Deferred government grants of the Consolidated VIEs without recourse to the primary beneficiaries	1,690	11,619	17,861
Amounts due to related parties related parties of the consolidated VIEs without resource to the primary beneficiaries	$ 73,373	¥ 504,478	¥ 0
Class A Ordinary Shares
Ordinary shares, par value (in dollars per share) \| $ / shares	$ 0.00001
Ordinary shares, shares authorized (in shares)	1,200,000,000	1,200,000,000	1,200,000,000
Ordinary shares, shares issued (in shares)	499,706,628	499,706,628	496,636,128
Ordinary shares, shares outstanding (in shares)	499,706,628	499,706,628	496,636,128
Class B Ordinary Shares
Ordinary shares, par value (in dollars per share) \| $ / shares	$ 0.00001
Ordinary shares, shares authorized (in shares)	300,000,000	300,000,000	300,000,000
Ordinary shares, shares issued (in shares)	174,649,638	174,649,638	174,649,638
Ordinary shares, shares outstanding (in shares)	174,649,638	174,649,638	174,649,638

Consolidated Statements of Operations ¥ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($) $ / shares shares	Dec. 31, 2018 CNY (¥) ¥ / shares shares	Dec. 31, 2017 CNY (¥) ¥ / shares shares	Dec. 31, 2016 CNY (¥) ¥ / shares shares
Net revenues
Hosting and related services	$ 494,660	¥ 3,401,037	¥ 2,975,178	¥ 2,668,655
Managed network services			417,527	973,119
Total net revenues	494,660	3,401,037	3,392,705	3,641,774
Hosting and related services	(357,235)	(2,456,166)	(2,130,279)	(1,936,658)
Managed network services			(504,016)	(992,980)
Total cost of revenues	(357,235)	(2,456,166)	(2,634,295)	(2,929,638)
Gross profit	137,425	944,871	758,410	712,136
Operating income (expenses)
Operating income	731	5,027	5,439	6,783
Sales and marketing expenses	(25,042)	(172,176)	(256,682)	(352,926)
Research and development expenses	(13,397)	(92,109)	(149,143)	(149,337)
General and administrative expenses	(67,288)	(462,637)	(519,950)	(639,648)
(Allowance) reversal for doubtful debt	87	598	(37,427)	(117,564)
Changes in the fair value of contingent purchase consideration payables	2,022	13,905	(937)	93,307
Impairment of long-lived assets			(401,808)	(392,947)
Impairment of goodwill		0	(766,440)	0
Total operating expenses	(102,887)	(707,392)	(2,126,948)	(1,552,332)
Operating (loss) profit	34,538	237,479	(1,368,538)	(840,196)
Interest income	6,572	45,186	32,925	21,078
Interest expenses	(34,334)	(236,066)	(185,313)	(198,589)
Impairment of long-term investment			(20,258)
Gain on disposal of subsidiaries	704	4,843	497,036
Loss on debt extinguishment				(29,841)
Other income	8,441	58,033	16,764	28,922
Other expenses	(597)	(4,103)	(17,060)	(16,449)
Foreign exchange gain (loss), net	(11,789)	(81,055)	(17,153)	56,341
(Loss) income before income taxes and gain (loss) from equity method investments	3,535	24,317	(1,061,597)	(978,734)
Income tax benefits (expenses)	(3,550)	(24,411)	90,170	11,160
Gain (loss) from equity method investments	(27,146)	(186,642)	53,783	35,652
Net loss	(27,161)	(186,736)	(917,644)	(931,922)
Net loss (income) attributable to noncontrolling interest and redeemable noncontrolling interest	(2,666)	(18,329)	144,914	298,324
Net loss attributable to the Company's ordinary shareholders	$ (29,827)	¥ (205,065)	¥ (772,730)	¥ (633,598)
Loss per share:
Basic (in per share) \| (per share)	$ (0.04)	¥ (0.30)	¥ (1.36)	¥ (1.37)
Diluted (in per share) \| (per share)	$ (0.04)	¥ (0.30)	¥ (1.36)	¥ (1.37)
Shares used in loss per share computation:
Weighted-average number of shares outstanding - basic (in shares) \| shares	674,732,130	674,732,130	672,836,226	617,169,833
Weighted-average number of shares outstanding-diluted (in shares) \| shares	674,732,130	674,732,130	672,836,226	617,169,833

Consolidated Statements of Comprehensive Loss ¥ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)	Dec. 31, 2016 CNY (¥)
Statement of Comprehensive Income [Abstract]
Net loss	$ (27,161)	¥ (186,736)	¥ (917,644)	¥ (931,922)
Other comprehensive income (loss), net of tax of nil:
Foreign currency translation adjustments, net of tax of nil	12,894	88,652	(120,963)	142,526
Other comprehensive income (loss), net of tax of nil	12,894	88,652	(120,963)	142,526
Comprehensive loss	(14,267)	(98,084)	(1,038,607)	(789,396)
Comprehensive loss (income) attributable to noncontrolling interest and redeemable noncontrolling interest	(2,666)	(18,329)	144,914	298,324
Comprehensive loss attributable to the Company's ordinary shareholders	$ (16,933)	¥ (116,413)	¥ (893,693)	¥ (491,072)

- Definition

The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 1A
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=114867106&loc=SL7669619-108580

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 50
-Paragraph 1A
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=109239629&loc=SL4573702-111684

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 1B
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=114867106&loc=SL7669625-108580

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 50
-Paragraph 1A
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=109239629&loc=SL4573702-111684

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 22
-URI http://asc.fasb.org/extlink&oid=115929826&loc=d3e8736-108599

Reference 6: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 55
-Paragraph 4J
-URI http://asc.fasb.org/extlink&oid=84234705&loc=SL4591551-111686

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3000-108585

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 45
-Paragraph 19
-URI http://asc.fasb.org/extlink&oid=108774443&loc=SL4569616-111683

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 32
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=115929826&loc=d3e8933-108599

Reference 10: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 55
-Paragraph 4K
-URI http://asc.fasb.org/extlink&oid=84234705&loc=SL4591552-111686

+ Details

Consolidated Statements of Comprehensive Loss (Parenthetical) ¥ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)	Dec. 31, 2016 CNY (¥)
Statement of Comprehensive Income [Abstract]
Foreign currency translation adjustments, tax	$ 0	¥ 0	¥ 0	¥ 0
Other comprehensive income, tax	$ 0	¥ 0	¥ 0	¥ 0

Consolidated Statements of Cash Flows ¥ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)	Dec. 31, 2016 CNY (¥)
CASH FLOWS FROM OPERATING ACTIVITIES
Net loss	$ (27,161)	¥ (186,736)	¥ (917,644)	¥ (931,922)
Adjustments to reconcile net loss to net cash generated from operating activities:
Foreign exchange (gain) loss,net	11,789	81,055	17,153	(56,341)
Changes in the fair value of contingent purchase consideration payables	(2,022)	(13,905)	937	(93,307)
Gain from settlement of contingent purchase consideration	(73)	(500)
Depreciation of property and equipment	82,393	566,491	523,500	480,105
Amortization of intangible assets	9,907	68,115	143,602	183,964
Loss (gain) on disposal of property and equipment and intangible assets	(1,161)	(7,981)	(3,285)	12,101
Allowance (reversal) for doubtful debt	(87)	(598)	37,427	117,564
Share based compensation expense	8,659	59,538	47,129	118,729
Deferred income tax benefits	(2,876)	(19,776)	(128,026)	(65,932)
(Gain) loss from equity method investments	27,146	186,642	(53,783)	(35,652)
Loss on debt extinguishment				29,841
Gain from disposal of equity investments without readily determinable fair value	(2,981)	(20,496)		(5,160)
Gain from disposal of equity method investment	(2,401)	(16,509)
Dividend income of equity investments without readily determinable fair values	(59)	(406)	(1,821)
Gain from disposal of subsidiaries	(704)	(4,843)	(497,036)
Impairment of long-lived assets			401,808	392,947
Impairment of goodwill		0	766,440	0
Impairment of long-term investment			20,258
Changes in operating assets and liabilities, net of effects of acquisitions and disposals:
Accounts and notes receivable	(10,008)	(68,809)	18,277	(40,988)
Inventories	(163)	(1,124)	(1,134)	9,108
Prepaid expenses and other current assets	(38,006)	(261,321)	(310,190)	(140,266)
Amounts due from related parties	(5,534)	(38,047)	4,436	(16,958)
Accounts and notes payables	6,018	41,380	42,468	46,947
Unrecognized tax benefits (expense)	(1,430)	(9,834)	(3,939)	14,197
Accrued expenses and other payables	11,308	77,744	270,082	82,216
Deferred revenue	291	2,001	(65,415)	(28,086)
Advances from customers	38,803	266,793	201,847	15,597
Income taxes payable	(29)	(198)	(6,548)	(28,060)
Deferred government grants	(966)	(6,643)	(4,985)	(6,627)
Amounts due to related parties	1,881	12,933	(14,356)	3,552
Net cash generated from operating activities	102,534	704,966	487,202	57,569
CASH FLOWS FROM INVESTING ACTIVITIES
Purchases of property and equipment	(63,300)	(435,220)	(395,998)	(574,501)
Purchases of intangible assets	(2,600)	(17,874)	(18,957)	(37,999)
Proceeds from disposal of property and equipment	2,244	15,429	5,719	51
Disposal of subsidiaries, net	493	3,389	(77,719)
Payments for short-term investments	(14,385)	(98,905)	(755,876)	(285,127)
Payment of loan to a third party	(2,909)	(20,000)
Receipt of loans to third parties	2,969	20,413	100,000	43,279
Proceeds received from maturity of short-term investments	60,744	417,643	484,932	112,300
Proceeds from disposal of long-term investments	11,004	75,653		11,269
Proceeds from dividend income of equity investments without readily determinable fair values	59	406	1,821
Payments for long-term investments	(36,765)	(252,780)	(162,176)	(48,701)
Payment for deposit to acquire data center	(1,891)	(13,000)
Receipt of deposit for disposal of subsidiaries			10,000
Payments for available-for-sale debt investments				(5,324)
Payments for assets acquisition, net of cash acquired			(25,053)	(56,264)
Net cash used in investing activities	(44,337)	(304,846)	(833,307)	(841,017)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from loan from a related party	6,405	44,038
Proceeds from exercise of stock options	63	435	926	4,510
Proceeds from issuance of ordinary shares				2,548,695
Payments for contingent purchase consideration in relation to acquisitions				(2,617)
Repayment of 2016 bonds/ 2017 bonds			(420,600)	(264,300)
Proceeds from issuance of 2020 Notes (Note 16)			1,936,154
Payment of issuance cost of 2020 Notes			(9,735)
Proceeds from long-term bank borrowings			44,440	214,620
Proceeds from short-term bank borrowings	10,181	69,999	70,000	1,725,676
Repayment of long-term bank borrowings	(10,275)	(70,643)	(94,037)	(49,320)
Repayment of short-term bank borrowings	(10,181)	(69,999)	(1,673,676)	(318,000)
Payments for purchase of mandatorily redeemable noncontrolling interests				(100,000)
Payments for purchase of property and equipment through capital leases	(40,708)	(279,886)	(199,126)	(23,638)
Repayment of loan from a third party			(100,000)
Rental prepayment and deposits for sales and leaseback transactions	(7,040)	(48,401)	(164,698)	(152,715)
Contribution from noncontrolling interest in subsidiaries	28,548	196,281	134,633	4,000
Prepayment for future share repurchase plan			(3,866)	(39,028)
Refund of prepayment for share repurchase plan	6,212	42,710
Payments for share repurchase plan			(133,066)	(42,665)
Proceeds from issuance of notes	13,899	95,565
Net cash generated from (used in) financing activities	(2,896)	(19,901)	(612,651)	1,908,883
Effect of foreign exchange rate changes on cash and cash equivalents and restricted cash	12,411	85,333	(140,298)	160,289
Net increase (decrease) in cash and cash equivalents and restricted cash	67,712	465,552	(1,099,054)	1,285,724
Cash and cash equivalents and restricted cash at beginning of the year	319,318	2,195,469	3,294,523	2,008,799
Cash and cash equivalents and restricted cash at end of the year	387,030	2,661,021	2,195,469	3,294,523
Reconciliation of cash and cash equivalents and restricted cash to the consolidated balance sheets
Cash and cash equivalents	343,038	2,358,556	1,949,631	1,297,418
Restricted cash-current	38,574	265,214	242,494	1,963,561
Restricted cash-non-current	5,418	37,251	3,344	33,544
Cash and cash equivalents and restricted cash at end of the year	387,030	2,661,021	2,195,469	3,294,523
Supplemental disclosures of cash flow information:
Income taxes paid	(8,350)	(57,407)	(55,076)	(50,349)
Interest paid	(23,414)	(160,984)	(96,846)	(155,679)
Interest received	7,388	50,793	28,857	19,886
Supplemental disclosures of non-cash activities:
Purchase of property and equipment through capital leases	128,699	884,871	453,786	240,474
Purchase of property and equipment included in accrued expenses and other payables	3,188	21,918	(15,750)	(51,669)
Purchase of intangible assets included in accrued expenses and other payables	127	870	1,354	(1,310)
Contingent purchase consideration related to the acquisitions included in amounts due to related parties and accrued expenses and other payables	$ 5,343	¥ 36,734	¥ (937)	(306,126)
Bonds 6.875% Due 2017
CASH FLOWS FROM FINANCING ACTIVITIES
Repurchase of 2017 bonds				¥ (1,596,335)

Consolidated Statements of Shareholders' Equity ¥ in Thousands, $ in Thousands	USD ($) shares	CNY (¥) shares	Ordinary shares USD ($) shares	Ordinary shares CNY (¥) shares	Treasury stock USD ($)	Treasury stock CNY (¥)	Additional paid-in capital USD ($)	Additional paid-in capital CNY (¥)	Accumulated other comprehensive (loss) income USD ($)	Accumulated other comprehensive (loss) income CNY (¥)	Statutory reserves USD ($)	Statutory reserves CNY (¥)	Accumulated deficit USD ($)	Accumulated deficit CNY (¥)	Total 21Vianet Group, Inc. shareholders' equity USD ($)	Total 21Vianet Group, Inc. shareholders' equity CNY (¥)	Non-controlling interest USD ($)	Non-controlling interest CNY (¥)
Beginning Balance (in shares) at Dec. 31, 2015 \| shares			522,512,594	522,512,594
Beginning balance at Dec. 31, 2015		¥ 4,034,375		¥ 34		¥ (193,142)		¥ 6,403,117		¥ (24,236)		¥ 63,174		¥ (2,233,985)		¥ 4,014,962		¥ 19,413
Consolidated net loss		(631,209)												(633,598)		(633,598)		2,389
Contribution from noncontrolling interest in a subsidiary		4,000																4,000
Foreign exchange difference		142,526								142,526						142,526
Issuance of new shares for stock consideration settlement (in shares) \| shares			10,087,476	10,087,476
Issuance of new shares for stock consideration settlement				¥ 1				(1)
Issuance of new shares for Tuspark Innovation Venture Limited (in shares) \| shares			143,050,264	143,050,264
Issuance of new shares for Tuspark Innovation Venture Limited		2,548,695		¥ 10				2,548,685								2,548,695
Issuance of new shares for share option exercised and restricted share units vested (in shares) \| shares			3,261,456	3,261,456
Issuance of new shares for share option exercised and restricted share units vested		1,119						1,119								1,119
Settlement of stock consideration settlement by treasury stock (in shares) \| shares			1,338,966	1,338,966
Settlement of stock consideration settlement by treasury stock		536				31,250		(30,714)								536
Share-based compensation		¥ 90,734						90,734								90,734
Shares issued to depository bank (in shares) \| shares	4,500,000	4,500,000	4,500,000	4,500,000
Reclassification of contingent purchase consideration payable upon resolution of contingencies		¥ 210,000						210,000								210,000
Appropriation of statutory reserves												1,448		(1,448)
Increase in accretion of redeemable noncontrolling interests		¥ (210,485)						(210,485)								(210,485)
Share repurchase (in shares) \| shares	(815,525)	(815,525)	(4,893,150)	(4,893,150)
Share repurchase		¥ (42,665)				(42,665)										(42,665)
Share options exercised (in shares) \| shares			921,594	921,594
Share options exercised		3,391						3,391								3,391
Restricted share units vested \| shares			6,957,984	6,957,984
Restricted share units vested		0	$ 0	¥ 0		0		0		0		0		0		0		0
Settlement of share options with shares held by depository bank (in shares) \| shares			(7,879,578)	(7,879,578)
Settlement of share options with shares held by depository bank		0	$ 0	¥ 0		0		0		0		0		0		0		0
Ending Balance (in shares) at Dec. 31, 2016 \| shares			679,857,606	679,857,606
Ending Balance at Dec. 31, 2016		6,151,017		¥ 45		(204,557)		9,015,846		118,290		64,622		(2,869,031)		6,125,215		25,802
Consolidated net loss		(775,748)												(772,730)		(772,730)		(3,018)
Cumulative adjustment for changes in accounting principles		(13,425)												(13,425)		(13,425)
Contribution from noncontrolling interest in a subsidiary		134,633																134,633
Foreign exchange difference		(120,963)								(120,963)						(120,963)
Issuance of new shares for share option exercised and restricted share units vested (in shares) \| shares			3,119,052	3,119,052
Share-based compensation		¥ 105,532						105,532								105,532
Shares issued to depository bank (in shares) \| shares	9,000,000	9,000,000	9,000,000	9,000,000
Share issued to depository bank				¥ 1				(1)
Appropriation of statutory reserves												2,083		(2,083)
Appropriation of dividend		¥ (5,946)																(5,946)
Disposal of subsidiaries												(27,969)		27,969
Increase in accretion of redeemable noncontrolling interests		¥ (141,896)						(141,896)								(141,896)
Share repurchase (in shares) \| shares	(3,448,482)	(3,448,482)	(20,690,892)	(20,690,892)
Share repurchase		¥ (133,126)				(133,126)										(133,126)
Share options exercised (in shares) \| shares			332,754	332,754
Share options exercised		926						926								926
Restricted share units vested \| shares			10,576,398	10,576,398
Restricted share units vested		0	$ 0	¥ 0		0		0		0		0		0		0		0
Settlement of share options with shares held by depository bank (in shares) \| shares			(10,909,152)	(10,909,152)
Settlement of share options with shares held by depository bank		0	$ 0	¥ 0		0		0		0		0		0		0		0
Ending Balance (in shares) at Dec. 31, 2017 \| shares			671,285,766	671,285,766
Ending Balance at Dec. 31, 2017		5,201,004		¥ 46		(337,683)		8,980,407		(2,673)		38,736		(3,629,300)		5,049,533		151,471
Consolidated net loss		(186,736)												(205,065)		(205,065)		18,329
Foreign exchange difference		89,129						477		88,652						89,129
Issuance of new shares for share option exercised and restricted share units vested (in shares) \| shares			3,070,500	3,070,500
Share-based compensation		67,009						67,009								67,009
Disposal of 49% interest in a subsidiary		196,281						93,166								93,166		103,115
Appropriation of statutory reserves												3,667		(3,667)
Disposal of subsidiaries		¥ (3,938)																(3,938)
Share repurchase (in shares) \| shares	0	0
Share options exercised (in shares) \| shares			219,972	219,972
Share options exercised		¥ 435						435								435
Restricted share units vested \| shares			5,115,558	5,115,558
Restricted share units vested		0	$ 0	¥ 0		0		0		0		0		0		0		0
Settlement of share options with shares held by depository bank (in shares) \| shares			(5,335,530)	(5,335,530)
Settlement of share options with shares held by depository bank		0	$ 0	¥ 0		0		0		0		0		0		0		0
Ending Balance (in shares) at Dec. 31, 2018 \| shares			674,356,266	674,356,266
Ending Balance at Dec. 31, 2018	$ 780,042	¥ 5,363,184	$ 7	¥ 46	$ (49,114)	¥ (337,683)	$ 1,329,575	¥ 9,141,494	$ 12,505	¥ 85,979	$ 6,167	¥ 42,403	$ (558,219)	¥ (3,838,032)	$ 740,921	¥ 5,094,207	$ 39,121	¥ 268,977

Consolidated Statements of Shareholders' Equity (Parenthetical) - Warburg Pincus	Dec. 31, 2018
Noncontrolling interest, ownership percentage	49.00%
Additional paid-in capital
Noncontrolling interest, ownership percentage	49.00%
Total 21Vianet Group, Inc. shareholders' equity
Noncontrolling interest, ownership percentage	49.00%
Non-controlling interest
Noncontrolling interest, ownership percentage	49.00%

Organization

12 Months Ended

Dec. 31, 2018

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Organization

1.	ORGANIZATION

21Vianet Group, Inc. was incorporated under the laws of the Cayman Islands on October 16, 2009 and its principal activity is investment holding. The Company through its consolidated subsidiaries and variable interest entities (the “VIEs”) are principally engaged in the provision of hosting and related services after the disposal of subsidiaries which are engaged in managed network services in September 2017 (Note 4).

(a)	As of December 31, 2018, the significant subsidiaries of the Company, VIEs and subsidiaries of VIEs are as follows:


Entity	Date of incorporation/ acquisition	Place of incorporation	Percentage of direct ownership by the Company			Principal activities
			Direct
Subsidiaries:
21ViaNet Group Limited (“21Vianet HK”)	May 25, 2007	Hong Kong		100	%	Investment holding
21ViaNet Data Center Co., Ltd. (“21Vianet China”) ⁽¹⁾	June 12, 2000	PRC		100	%	Provision of technical and consultation services and rental of long-lived assets
21Vianet (Foshan) Technology Co., Ltd. (“FS Technology”) ⁽¹⁾	December 20, 2011	PRC		100	%	Trading of network equipment, provision of technical and internet data center services
21Vianet Anhui Suzhou Technology Co., Ltd. (“SZ Technology”) ⁽¹⁾	November 16, 2011	PRC		100	%	Trading of network equipment
21Vianet Hangzhou Information Technology Co., Ltd. (“HZ Technology”) ⁽¹⁾	March 4, 2013	PRC		100	%	Provision of internet data center services
21Vianet Mobile Limited (“21V Mobile”)	April 30, 2013	Hong Kong		100	%	Investment holding and provision of telecommunication services
Joytone Infotech Co., Ltd. (“SZ Zhuoaiyi”) ⁽¹⁾	April 30, 2013	PRC		100	%	Provision of technical and consultation services
21Vianet Ventures Limited (“Ventures”)	March 6, 2014	Hong Kong		100	%	Investment holding
Abitcool (China) Broadband Inc. (“aBitCool DG”) ⁽¹⁾	June 13, 2014	PRC		100	%	Dormant company
Diyixian.com Limited (“DYX”)	August 10, 2014	Hong Kong		100	%	Provision of virtual private network services
21Vianet Zhuhai Financial Leasing Co., Ltd. (“Zhuhai Financial Leasing”) ⁽¹⁾	April 9, 2015	PRC		100	%	Provision of financial leasing business services
21Vianet DRP Investment Holdings Limited (“DRP investment”)	January 10, 2017	Hong Kong		100	%	Investment holding
Shihua DC Investment Holdings Limited (“Shihua Investment”)	March 14, 2017	Cayman		51	%	Investment holding
21Vianet (Xi’an) Technology Co., Ltd. (“Xi’an Tech”) ⁽¹⁾	July 5, 2012	PRC		51	%	Provision of technical and internet data center services
Foshan Zhuoyi Intelligence Data Co., Ltd. (“FS Zhuoyi”) ⁽¹⁾	July 7, 2016	PRC		51	%	Provision of internet data center services
Dermot Holding Limited (“Dermot BVI”) ⁽³⁾	August 8, 2014	British Virgin Islands		100	%	Investment holding

Variable Interest Entities (the “VIEs”):
Beijing Yiyun Network Technology Co., Ltd. (“21Vianet Technology”)⁽¹⁾^/(2)	October 22, 2002	PRC		—		Provision of internet data center services
Beijing iJoy Information Technology Co., Ltd. (“BJ iJoy”) ^(1)/(2)	April 30, 2013	PRC		—		Provision of internet data center, content delivery network services
WiFire Network Technology (Beijing) Co., Ltd. (“WiFire Network”) ^(1)/(2)	April 1, 2014	PRC		—		Provision of telecommunication services

Held directly by 21Vianet Technology:
Beijing 21Vianet Broad Band Data Center Co., Ltd. (“21Vianet Beijing”) ^(1)/(2)	March 15, 2006	PRC		—		Provision of internet data center services

Held directly by 21Vianet Beijing:
21Vianet (Xi’an) Information Outsourcing Industry Park Services Co., Ltd. (“Xi’an Sub”) ^(1)/(2)	June 23, 2008	PRC		—		Provision of internet data center services
Langfang Xunchi Computer Data Processing Co., Ltd. (“LF Xunchi”) ^(1)/(2)	December 19, 2011	PRC		—		Dormant company
Shanghai Blue Cloud Technology Co., Ltd. (“SH Blue Cloud”) ^(1)/(2)	March 21, 2013	PRC		—		Provision of Office 365 and Windows Azure platform services
Beijing Yichengtaihe Investment Co., Ltd. (“BJ Yichengtaihe”) ^(1)/(2)	September 30, 2014	PRC		—		Provision of internet data center services
Beijing Hongyuan Network Technology Co., Ltd. (“BJ Hongyuan”) ^(1)/(2)/(4)	December 8, 2014	PRC		—		Provision of internet data center services
Guangzhou Lianyun Big Data Co. Ltd.^(1)/(2)	April 14, 2016	PRC		—		Provision of internet data center services

Held directly by DYX and LF Xunchi:
Shenzhen Diyixian Telecommunication Co., Ltd. (“SZ DYX”) ⁽¹⁾	August 10, 2014	PRC		100	%	Provision of virtual private network services

(1)	Collectively, the “PRC Subsidiaries”.

(2)	Collectively, the “Consolidated VIEs”.

(3)	On August 10, 2014, the Company and its subsidiary, LF Xunchi, acquired 100% equity interest Dermot BVI and its subsidiaries (collectively referred to as “Dermot Entities”).

(4)	On August 15, 2018, the Company through its subsidiary, 21Vianet Beijing disposed 49% equity interest of BJ Hongyuan to a third party.

(b)

PRC laws and regulations prohibit foreign ownership of internet and telecommunications-related businesses. To comply with these foreign ownership restrictions, the Company conducts its businesses in the PRC through its VIEs using contractual agreements (the “VIE Agreements”). The equity interests of 21Vianet Technology are legally held by certain PRC individuals, including Chen Sheng, the Executive Chairman of Board of Directors of the Company and Zhang Jun (collectively the “Nominee Shareholders”). The following is a summary of the key terms of the VIE Agreements:

Exclusive option agreement

Pursuant to the exclusive option agreement entered into amongst 21Vianet China and the Nominee Shareholders of 21Vianet Technology, the Nominee Shareholders granted the Company or its designated party, an exclusive irrevocable option to purchase all or part of the equity interests held by the Nominee Shareholders in 21Vianet Technology, when and to the extent permitted under the PRC laws, at an amount equal to RMB1. 21Vianet Technology cannot declare any profit distributions or grant loans in any form without the prior written consent of 21Vianet China. The Nominee Shareholders must remit in full any funds received from 21Vianet Technology to 21Vianet China, in the event any distributions are made by 21Vianet Technology. The term of this agreement is 10 years, expiring on December 18, 2016, which is renewable at the sole discretion of 21Vianet China. On December 19, 2016, this agreement was renewed for another 10 years, expiring on December 18, 2026.

Exclusive technical consulting and service agreement

Pursuant to the exclusive technical consulting and service agreement entered into between 21Vianet China and 21Vianet Technology, 21Vianet China is to provide exclusive management consulting services and internet technical services in return for fees based on of a predetermined hourly rate of RMB1, which is adjustable at the sole discretion of 21Vianet China. The term of this agreement is 10 years, expiring on December 18, 2016, which is renewable at the sole discretion of 21Vianet China. On December 19, 2016, this agreement was renewed for another 10 years, expiring on December 18, 2026.

Loan agreement

In January 2011, 21Vianet China and the Nominee Shareholders entered into a loan agreement. Pursuant to the agreement, 21Vianet China has provided interest-free loan facilities of RMB7,000 and RMB3,000, respectively, to the Nominee Shareholders of 21Vianet Technology for the purpose of providing capital to 21Vianet Technology to develop its data center and telecommunications value-added business and related businesses. There is no fixed term for the loan.

Power of attorney agreement

The Nominee Shareholders entered into the power of attorney agreement whereby they granted an irrevocable proxy of the voting rights underlying their respective equity interests in 21Vianet Technology to 21Vianet China, which includes, but are not limited to, all the shareholders’ rights and voting rights empowered to the Nominee Shareholders by the company law and 21Vianet Technology’s Articles of Association. The power of attorney remains valid and irrevocable from the date of execution, so long as each Nominee Shareholder remains as a shareholder of 21Vianet Technology.

The power of attorney agreement was subsequently reassigned to 21Vianet Group, Inc. in September 2010.

Share pledge agreement

Pursuant to the share pledge agreement entered into amongst 21Vianet China, 21Vianet Technology and the Nominee Shareholders, the Nominee Shareholders have contemporaneously pledged all their equity interests in 21Vianet Technology to guarantee the repayment of the loan under the Loan Agreement between 21Vianet China and the Nominee Shareholders.

On August 10, 2015, a Notification of Cancellation of share pledge registration was issued by Beijing Administration for Industry and Commerce, Pinggu Branch to cancel the registration of the share pledge by one of the Nominee Shareholders, Zhang Jun. Such cancellation does not affect the effectiveness of the share pledge agreement and does not lessen the control imposed on the contractual parties of the Company.

If 21Vianet Technology breaches its respective contractual obligations under the Share pledge agreement and the loan agreement, 21Vianet China, as pledgee, will be entitled to certain rights, including the right to sell the pledged equity interests. The Nominee Shareholders agreed not to transfer, sell, pledge, dispose of or otherwise create any new encumbrance on their equity interests in 21Vianet Technology without the prior written consent of 21Vianet China.

Financial support letter

Pursuant to the financial support letter, 21Vianet Group, Inc. agreed to provide unlimited financial support to 21Vianet Technology for its operations and agreed to forego the right to seek repayment in the event 21Vianet Technology is unable to repay such funding.

The Company also controls two other VIEs, namely BJ iJoy and WiFire Network through their primary beneficiary, aBitCool DG and SZ Zhuoaiyi, wholly owned subsidiaries of the Company. The key terms of the VIE Agreements in relation to BJ iJoy and WiFire Network are similar to those summarized above.

Despite the lack of technical majority ownership, there exists a parent-subsidiary relationship between the Company and 21Vianet Technology through the irrevocable power of attorney agreement, whereby the Nominee Shareholders effectively assigned all of their voting rights underlying their equity interests in 21Vianet Technology to the Company. In addition, the Company, through 21Vianet China, obtained effective control over 21Vianet Technology through the ability to exercise all the rights of 21Vianet Technology’s shareholders pursuant to the share pledge agreement and exclusive option agreement. The Company demonstrates its ability and intention to continue to exercise the ability to absorb substantially all of the expected losses through the financial support letter. In addition, the Company also demonstrates its ability to receive substantially all of the economic benefits of 21Vianet Technology through 21Vianet China through the consulting and service agreement. Thus, the Company is the primary beneficiary of 21Vianet Technology and consolidates 21Vianet Technology and its subsidiaries under Accounting Standards Codification (“ASC”) Subtopic 810-10, Consolidation: Overall, (“ASC 810-10”). Similar conclusion has been reached with respect to the VIE structures with aBitCool DG and SZ Zhuoaiyi as the primary beneficiary.

In the opinion of the Company’s management and PRC counsel, (i) the ownership structure of the VIEs is in compliance with applicable PRC laws and regulations in any material respect, and (ii) each of the VIE Agreements is valid, legally binding and enforceable to each party of such agreements under the existing PRC laws and will not violate any PRC laws or regulations currently in effect.

However, there are substantial uncertainties regarding the interpretation and application of current and future PRC laws and regulations. Accordingly, the Company cannot be assured that PRC regulatory authorities will not ultimately take a contrary view to its opinion. If the current ownership structure of the Company and its contractual arrangements with the VIEs are found to be in violation of any existing or future PRC laws and regulations, the Company may be required to restructure its ownership structure and operations in the PRC to comply with the changing and new PRC laws and regulations. To the extent that changes and new PRC laws and regulations prohibit the Company’s VIE arrangements from complying with the principles of consolidation, the Company would have to deconsolidate the financial position and results of operations of its VIEs. In the opinion of management, the likelihood of loss in respect of the Company’s current ownership structure or the contractual arrangements with the VIEs is remote based on current facts and circumstances.

(c)

VIE disclosures

Except for certain property with carrying amounts of RMB302,999 (US$44,069) that were pledged to secure banking borrowings granted to the Company (Note 13), there were no pledges or collateralization of the Consolidated VIEs’ assets. Creditors of the Consolidated VIEs have no recourse to the general credit of the primary beneficiaries of the Consolidated VIEs, and such amounts have been parenthetically presented on the face of the consolidated balance sheets. The Consolidated VIEs operate the data centers and own facilities including data center buildings, leasehold improvements, fiber optic cables, computers and network equipment, which are recognized in the Company’s consolidated financial statements. They also hold certain value-added technology licenses, registered copyrights, trademarks and registered domain names, including the official website, which are also considered as revenue-producing assets. However, none of such assets was recorded on the Company’s consolidated balance sheets as such assets were all acquired or internally developed with insignificant cost and expensed as incurred. In addition, the Company also hires data center operation and marketing workforce for its daily operations and such costs are expensed when incurred. The Company has not provided any financial or other support that it was not previously contractually required to provide to the Consolidated VIEs during the periods presented.

(d)

Cooperation with Waburg Pincus

In March 2017, the Company entered into an investment agreement with Warburg Pincus to establish a multi-stage joint venture and build a digital real estate platform in China. The Company seeded the initial JV with high-performing IDC assets, and Warburg Pincus contributed direct capital and extensive industry network and resources in the real estate sector. The Company owns 51% of the equity interests in the existing internet data center (“IDC”) assets while Warburg Pincus owns the remaining 49%. On March 14, 2017, Shihua Investment was established by the Company and a subsidiary of Warburg Pincus, with the equity interest of 51% and 49%, respectively.

In March 2017, the Company and Warburg Pincus set up two JVs, Shihua DC Investment Holdings 2 Limited and Shihua DC Investment Management Limited (collectively, “Shihua DC Holdings”) (Note 12), with the equity interest of 49% and 51%, respectively. The Company accounted for the investment in the two JVs under equity method investments for its ability to exercise significant influence.

(e)

Variable interests in a VIE

As of December 31, 2018, the Company held variable interest in an entity that does not have sufficient equity at risk where the Company is not the VIE’s primary beneficiary to consolidate the VIE. The Company’s maximum exposure to such an arrangement is RMB46,445 (US$6,755).

The following tables represent the financial information of the Consolidated VIEs as of December 31, 2017 and 2018 and for the years ended December 31, 2016, 2017 and 2018 before eliminating the intercompany balances and transactions between the Consolidated VIEs and other entities within the Company:


	As of December 31,
	2017		2018
	RMB		RMB		US$
ASSETS
Current assets:
Cash and cash equivalents		233,673		548,921		79,837
Restricted cash		149,375		203,103		29,540
Accounts receivable (net of allowance for doubtful debt of RMB70,627 and RMB69,723 (US$10,141) as of December 31, 2017 and 2018, respectively)		342,276		375,515		54,616
Short-term investments		—		94,000		13,672
Prepaid expenses and other current assets		809,546		1,013,563		147,417
Amounts due from related parties		86,824		123,726		17,995

Total current assets		1,621,694		2,358,828		343,077

Non-current assets:
Property and equipment, net		2,331,139		3,103,995		451,457
Intangible assets, net		45,203		47,121		6,853
Land use rights, net		74,162		60,078		8,738
Goodwill		302,956		302,647		44,018
Restricted cash		—		33,729		4,906
Deferred tax assets		169,224		156,412		22,749
Amounts due from related parties		—		13,514		1,966
Other non-current assets		67,517		162,392		23,619
Long-term investments		355,894		219,005		31,853

Total non-current assets		3,346,095		4,098,893		596,159

Total assets		4,967,789		6,457,721		939,236

Current liabilities:
Short-term bank borrowings		50,000		50,000		7,272
Accounts and notes payable		157,970		258,048		37,532
Accrued expenses and other payables		368,190		392,619		57,104
Advance from customers		403,244		670,037		97,453
Deferred revenue		49,699		51,026		7,421
Income tax payable		7,400		8,519		1,239
Amounts due to inter-companies ⁽¹⁾		1,863,780		2,117,097		307,919
Amounts due to related parties		16,053		51,763		7,529
Current portion of capital lease obligations		201,315		219,695		31,953
Current portion of long-term bank borrowings		70,289		75,284		10,950
Deferred government grants		4,574		4,173		607

Total current liabilities		3,192,514		3,898,261		566,978


	As of December 31,
	2017		2018
	RMB		RMB		US$
Non-current liabilities:
Amounts due to inter-companies ⁽¹⁾		1,020,972		1,020,972		148,494
Amounts due to related parties		—		504,478		73,373
Non-current portion of long-term bank borrowings		187,638		112,000		16,290
Non-current portion of capital lease obligations		687,176		852,287		123,960
Unrecognized tax benefits		13,225		4,938		718
Deferred tax liabilities		109,339		84,568		12,300
Deferred government grants		17,861		11,619		1,690

Total non-current liabilities		2,036,211		2,590,862		376,825

Total liabilities		5,228,725		6,489,123		943,803


	For the years ended December 31,
	2016			2017			2018
	RMB			RMB			RMB		US$
Net revenues		2,938,319			2,578,893			2,532,854		368,388
Net (loss) profit		(674,685	)		(567,395	)		52,986		7,706


	For the years ended December 31,
	2016 (As adjusted)			2017 (As adjusted)			2018
	RMB			RMB			RMB			US$
Net cash generated from operating activities		106,803			448,051			693,620			100,883
Net cash (used in) generated from investing activities		(470,955	)		(604,507	)		132,522			19,279
Net cash generated from (used in) financing activities		145,678			230,921			(423,467	)		(61,590	)
Net (decrease) increase in cash and cash equivalents and restricted cash		(218,474	)		74,465			402,705			58,572

(1)

Amounts due to inter-companies consist of intercompany payables to the other companies within the Company for the purchase of telecommunication resources and fixed assets on behalf of the Consolidated VIEs.

Summary of Significant Accounting Policies

12 Months Ended

Dec. 31, 2018

Accounting Policies [Abstract]

Summary of Significant Accounting Policies

2.	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

(a)

Basis of presentation

The accompanying consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”).

(b)

Principles of consolidation

The consolidated financial statements include the financial statements of the Company, its subsidiaries and the Consolidated VIEs for which the Company or a subsidiary of the Company is the primary beneficiary. All significant inter-company transactions and balances between the Company, its subsidiaries and the Consolidated VIEs are eliminated upon consolidation. Results of acquired subsidiaries and its Consolidated VIEs are consolidated from the date on which control is transferred to the Company.

(c)

Use of estimates

The preparation of the consolidated financial statements in conformity with US GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosures of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the period. Significant estimates and assumptions reflected in the Company’s financial statements include, but are not limited to, estimating the useful lives of long-lived assets, determining the fair value of equity method investments, accounting for investments and the subsequent impairment assessment, determining the provision for accounts and other receivable, determining the valuation allowance for deferred tax assets, accounting for share-based compensation arrangements, and determining the standalone lease price. Changes in facts and circumstances may result in revised estimates. Actual results could differ from those estimates, and as such, differences may be material to the consolidated financial statements.

(d)

Foreign currency

The functional currency of the Company and its overseas subsidiaries is the US$, whereas the functional currency of the Company’s PRC subsidiaries and its Consolidated VIEs is the RMB as determined based on the criteria of ASC Topic 830, Foreign Currency Matters, (“ASC 830”). The Company uses the RMB as its reporting currency.

The financial statements of the Company and its overseas subsidiaries are translated from the functional currency to the reporting currency, RMB. Transactions denominated in foreign currencies are re-measured into the functional currency at the exchange rates prevailing on the transaction dates. Monetary assets and liabilities denominated in foreign currencies are re-measured at the exchange rates prevailing at the balance sheet date. Non-monetary items that are measured in terms of historical costs in foreign currency are re-measured using the exchange rates at the dates of the initial transactions. Exchange gains and losses are included in the consolidated statements of operations.

The Company uses the average exchange rate for the year and the exchange rate at the balance sheet date to translate the operating results and financial position, respectively. Translation differences are recorded in accumulated other comprehensive (loss) income.

(e)

Convenience translation

Amounts in US$ are presented for the convenience of the reader and are translated at the noon buying rate of US$1.00 to RMB6.8755 on December 31, 2018, the last business day in fiscal year 2018, representing the noon buying rate set forth in the H.10 statistical release of the U.S. Federal Reserve Board. No representation is made that the RMB amounts could have been, or could be converted, realized or settled into US$ at such rate or at any other rate.

(f)

Cash and cash equivalents

Cash and cash equivalents consist of cash on hand and demand deposits placed with banks which are unrestricted as to withdrawal and use and have original maturities less than three months. All highly liquid investments with a stated maturity of 90 days or less from the date of purchase are classified as cash equivalents.

(g)

Restricted cash

Restricted cash mainly represents amounts held by a few banks in escrow as security for credit facilities, the guarantee of compliance with the network and service requirements of the radio spectrum license awarded by the Hong Kong Telecommunication Authority, the deposits for capital lease, the deposits held in escrow for the advances received from end customers subscribing Office 365 and Windows Azure services (the disbursement of which shall be agreed by both Microsoft (China) Co., Ltd. (“Microsoft”) and the Company).

The Company adopted Accounting Standards Update (“ASU”) No. 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash, (“ASU 2016-18”), effective January 1, 2018 using the retrospective transition method and included all restricted cash with cash and cash equivalent when reconciling beginning-of-period and end-of-period total amounts presented in the consolidated statements of cash flows.

(h)

Short-term investments

All highly liquid investments with original maturities of greater than three months but less than twelve months, are classified as short-term investments. Interest income is included in earnings.

(i)

Accounts receivable and allowance for doubtful debt

Accounts receivable are carried at net realizable value. An allowance for doubtful debt is recorded in the period when loss is probable based on an assessment of specific evidence indicating troubled collection, historical experience, accounts aging and other factors. An accounts receivable is written off after all collection effort has ceased.

(j)

Inventories

Inventories are stated at the lower of cost or net realizable value. Cost of inventory are determined using the first-in, first-out method. The Company records inventory reserves for obsolete and slow moving inventory. Inventory reserves are based on inventory obsolescence trends, historical experience and application of the specific identification method. For all periods presented, there were no inventory reserves recognized.

(k)

Property and equipment

Property and equipment are stated at cost less accumulated depreciation and any recorded impairment. Property and equipment acquired in a business combination are recognized initially at fair value at the date of acquisition. Property and equipment are depreciated using the straight-line method over the estimated useful lives of the assets, as follows:


Category		Estimated useful life
Property		25-46 years
Leasehold improvements		Over the shorter of lease term or the estimated useful lives of the assets
Optical fibers		10-20 years
Computer and network equipment		1-10 years
Office equipment		1-8 years
Motor vehicles		4-8 years

Repair and maintenance costs are charged to expense as incurred, whereas the costs of betterments that extend the useful life of property and equipment are capitalized as additions to the related assets. Retirements, sale and disposals of assets are recorded by removing the cost and accumulated depreciation with any resulting gain or loss reflected in the consolidated statements of operations.

Property and equipment that are purchased or constructed which require a period of time before the assets are ready for their intended use are accounted for as construction-in-progress. Construction-in-progress is recorded at acquisition cost, including installation costs. Construction-in-progress is transferred to specific property and equipment accounts and commences depreciation when these assets are ready for their intended use.

(l)

Intangible assets

Intangible assets are carried at cost less accumulated amortization and any recorded impairment. Intangible assets acquired in a business combination are recognized initially at fair value at the date of acquisition. Intangible assets with finite useful lives are amortized using a straight-line method. These amortization methods reflect the estimated pattern in which the economic benefits of the respective intangible assets are to be consumed.

The Company has capitalized certain internal use software development costs in accordance with ASC Subtopic 350-40, Intangibles-Goodwill and Other: Internal-Use Software, (“ASC 350-40”), amounting to RMB12,781, RMB9,238 and RMB6,093 (US$886) for the years ended December 31, 2016, 2017 and 2018, respectively. The Company capitalizes certain costs relating to software acquired, developed, or modified solely to meet the Company’s internal requirements and for which there are no substantive plans to market the software. These costs mainly include the consulting and service fees paid to a third-party developer that are directly associated with the internal-use software projects during the application development stage and the research staff costs directly associated with the internal-develop software projects during the application development stage. Capitalized internal-use software costs are included in “intangible assets, net”.

Intangible assets have weighted average useful lives from the date of purchase/ acquisition as follows:


Purchased software			6.5 years
Radio spectrum license			15 years
Contract backlog*			4.9 years
Customer relationships*			8.8 years
Supplier relationships*			10 years
Licenses*			15 years
Trade Name*			20 years
Platform software*			5 years
Non-compete agreement*			5 years
Internal-use software			4.9 years

Acquired in the acquisitions of subsidiaries.

(m)

Land use rights

The land use rights represent the amounts paid and relevant costs incurred for the rights to use land in the PRC and are recorded at purchase cost less accumulated amortization. Amortization is provided on a straight-line basis over the terms of the respective land use rights certificates.

(n)

Long-term investments

The Company’s long-term investments consist of equity investments without readily determinable fair value, equity method investments and available-for-sale debt investments.

Prior to adopting ASC Topic 321, Investments—Equity Securities, (“ASC 321”), on January 1, 2018, the Company carries at cost its investments in investees that do not have readily determinable fair value and over which the Company does not have significant influence, in accordance with ASC Subtopic 325-20, Investments-Other: Cost Method Investments, (“ASC 325-20”). The Company only adjusts the carrying value of such investments for other-than-temporary decline in fair value and for distribution of earnings that exceed the Company’s share of earnings since its investment.

Management regularly evaluates the impairment of equity investments without readily determinable fair value based on the performance and financial position of the investee as well as other evidence of market value. Such evaluation includes, but is not limited to, reviewing the investee’s cash position, recent financing, projected and historical financial performance, cash flow forecasts and financing needs. An impairment loss is recognized in earnings equal to the excess of the investment’s cost over its fair value at the balance sheet date of the reporting period for which the assessment is made. The fair value would then become the new cost basis of the investment.

The Company adopted ASC 321 on January 1, 2018 and the cumulative effect of adopting the new standard on opening accumulated deficit is nil. Pursuant to ASC 321, equity investments, except for those accounted for under the equity method and those that result in consolidation of the investee and certain other investments, are measured at fair value, and any changes in fair value are recognized in earnings. For equity securities without readily determinable fair value and do not qualify for the existing practical expedient in ASC Topic 820, Fair Value Measurements and Disclosures, (“ASC 820”), to estimate fair value using the net asset value per share (or its equivalent) of the investment, the Company elected to use the measurement alternative to measure those investments at cost, less any impairment, plus or minus changes resulting from observable price changes in orderly transactions for identical or similar investments of the same issuer, if any. Equity securities with readily determinable fair value are measured at fair values, and any changes in fair value are recognized in earnings.

Pursuant to ASC 321, for equity investments measured at fair value with changes in fair value recorded in earnings, the Company does not assess whether those securities are impaired. For those equity investments that the Company elects to use the measurement alternative, the Company makes a qualitative assessment of whether the investment is impaired at each reporting date. If a qualitative assessment indicates that the investment is impaired, the entity has to estimate the investment’s fair value in accordance with the principles of ASC 820. If the fair value is less than the investment’s carrying value, the entity has to recognize an impairment loss in net income equal to the difference between the carrying value and fair value.

Available-for-sale debt investments are convertible debt instruments issued by private companies, which are measured at fair value, with unrealized gains or losses recorded in accumulated other comprehensive income.

Investments in equity investees represent investments in entities in which the Company can exercise significant influence but does not own a majority equity interest or control are accounted for using the equity method of accounting in accordance with ASC Subtopic 323-10, Investments-Equity Method and Joint Ventures: Overall, (“ASC 323-10”). The Company applies the equity method of accounting that is consistent with ASC323-10 in limited partnerships in which the Company holds a three percent or greater interest. Under the equity method, the Company initially records its investment at cost and prospectively recognizes its proportionate share of each equity investee’s net profit or loss into its consolidated statements of operations. The difference between the cost of the equity investee and the amount of the underlying equity in the net assets of the equity investee is recognized as equity method goodwill included in equity method investments on the consolidated balance sheets. The Company evaluates its equity method investments for impairment under ASC 323-10. An impairment loss on the equity method investments is recognized in the consolidated statements of operations when the decline in value is determined to be other-than-temporary.

(o)

Goodwill

Goodwill represents the excess of the purchase price over the amounts assigned to the fair value of the assets acquired and the liabilities assumed of an acquired business. In accordance with ASC Topic 350, Goodwill and Other Intangible Assets, (“ASC 350”), recorded goodwill amounts are not amortized, but rather are tested for impairment annually or more frequently if there are indicators of impairment present.

In accordance with ASC 350, the Company assigned and assessed goodwill for impairment at the reporting unit level. A reporting unit is an operating segment or one level below the operating segment. Prior to the change in segment reporting in 2016, the Company had one single reporting unit which is also its only operating segment. Goodwill that has arisen as a result of the acquisitions of subsidiaries was assigned to this reporting unit. Immediately upon the change in segment reporting in 2016, there were two reporting units consisting of two service lines namely hosting and related services and managed network services. The goodwill was reassigned to the two reporting units using a relative fair value allocation approach.

After the disposal of WiFire Entities and Aipu Group as defined in Note 4 in September 2017, the Company determined that there is only hosting and related services remained and hence the Company as a whole is one reporting unit as of December 31, 2018.

The Company early adopted ASU No. 2017-04, Simplifying the Test for Goodwill Impairment, (“ASU 2017-04”), which simplifies the accounting for goodwill impairment by eliminating Step two from the goodwill impairment test. Under the new guidance, if a reporting unit’s carrying amount exceeds its fair value, an entity will record an impairment charge based on that difference. The impairment charge will be limited to the amount of goodwill allocated to that reporting unit. Fair value is primarily determined by computing the future discounted cash flows expected to be generated by the reporting unit.

Immediately before the disposal of WiFire Entities and Aipu Group in September 2017, the Company completed its impairment test for goodwill in managed network services. The Company determined the fair value of the reporting unit using the income approach based on the discounted expected cash flows associated with the reporting unit. The discounted cash flows for the reporting unit were based on five-year projections. Cash flow projections were based on past experience, actual operating results and management best estimates about future developments as well as certain market assumptions. Cash flows after five years were estimated using a terminal value calculation, which considered terminal value growth at 3%, considering the long-term revenue growth for entities in a similar industry in the PRC. The discount rate of approximately 13% was derived and used in the valuations which reflect the market assessment of the risks specific to the Company and its industry and is based on its weighted average cost of capital. The resulting fair value of the reporting unit significant lower than its carrying value, the Company fully impaired goodwill in managed network services and recorded an amount of RMB766 million for impairment loss of goodwill as of December 31, 2017.

Pursuant to ASC 350, the Company elected to perform a qualitative assessment for hosting and related services. As of October 1, 2018, the Company completed its annual impairment test for goodwill that has arisen out of its acquisitions. The Company evaluated all relevant factors including, but not limited to, macroeconomic conditions, industry and market conditions, financial performance, and the share price of the Company. The Company weighed all factors in their entirety and concluded that it was not more-likely-than-not the fair value was less than the carrying amount of the reporting unit, and further impairment testing on goodwill was unnecessary.

No impairment loss of goodwill in hosting and related services was recognized for the years ended December 31, 2016, 2017 and 2018, respectively.

(p)

Impairment of long-lived assets

The Company evaluates its long-lived assets or asset group, including intangible assets with finite lives, for impairment whenever events or changes in circumstances (such as a significant adverse change to market conditions that will impact the future use of the assets) indicate that the carrying amount of an asset or a group of long-lived assets may not be recoverable. When these events occur, the Company evaluates for impairment by comparing the carrying amount of the assets to future undiscounted net cash flows expected to result from the use of the assets and their eventual disposition. If the sum of the expected undiscounted cash flow is less than the carrying amount of the assets, the Company would recognize an impairment loss based on the excess of the carrying amount of the asset group over its fair value. Fair value is generally determined by discounting the cash flows expected to be generated by the assets, when the market prices are not readily available for the long-lived assets.

In 2016, due to the deterioration of the operating results of one of the Company’s asset group, the Company recognized an impairment loss based on the excess of the carrying amount of the asset group over its fair value. The Company determined the fair value of the asset group using the income approach based on the discounted expected cash flows associated with the asset group. The discounted cash flows for the asset group were based on eight year projections which is consistent with the remaining useful lives of its principal assets. Cash flow projections were based on past experience, actual operating results and management best estimates about future developments as well as certain market assumptions. The discount rate of approximately 13% was derived and used in the valuations which reflect the market assessment of the risks specific to the Company and its industry and is based on its weighted average cost of capital.

As of December 31, 2017, due to continued operational losses, the Company recorded the long-lived assets impairment amounting to RMB170,695 and RMB231,113 for the asset groups of Aipu Group and WiFire Entities, respectively, resulting from excess of the carrying amount of the asset groups over their fair values of the two asset groups, respectively.

The Company determined the fair value of the asset groups using the income approach based on the discounted expected cash flows associated with the respective asset groups. The discounted cash flows for the asset groups were based on seven year projections for Aipu and five years for WiFire Entities, which are consistent with the remaining useful lives of its principal assets. Cash flow projections were based on the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. The discount rate of approximately 13% was derived and used in the valuations which reflect the market assessment of the risks specific to the Company and its industry and is based on its weighted average cost of capital. No impairment was recognized in other assets groups as there was no impairment indicator identified.

The impairment loss reduced the carrying amount of the long-lived assets of a group on a pro-rata basis using the relative carrying amount of those assets.

In 2018, the Company performed a qualitative assessment for impairment on whether events or changes in circumstances indicate that the carrying amount of an asset or a group of long-lived assets might not be recoverable. No impairment was recognized for the year ended December 31, 2018 as there was no impairment indicator identified.

The Company recorded impairment charges associated with its long-lived assets and acquired intangibles as follows:


	For the years ended December 31,
	2016		2017		2018
	RMB		RMB		RMB		US$
Impairment of equipment		238,144		237,956		—		—
Impairment of intangible assets		154,803		163,852		—		—

(q)

Fair value of financial instruments

The Company’s financial instruments include cash and cash equivalents, restricted cash, short-term investments, accounts receivable and payable, other receivables and payables, bonds payable, short-term and long-term bank borrowings, available-for-sale debt securities, share-settled bonus, liability classified restricted share units (“RSU”), and the contingent purchase consideration payable included in the balances with related parties. Other than the bonds payable, long-term bank borrowings, share-settled bonus and the contingent purchase consideration payable included in the balances with related parties, the carrying values of these financial instruments approximate their fair values due to their short-term maturities.

The carrying amounts of long-term bank borrowings approximate their fair values since they bear interest rates which approximate market interest rates. The contingent purchase considerations in both cash and shares and share-settled bonus are initially measured at fair value on the acquisition dates of the acquired businesses and the date of grant, respectively, and subsequently remeasured at the end of each reporting period with an adjustment for fair value recorded to the current period income (expense).

(r)

Revenue recognition

The Company provides hosting and related services including hosting of customers’ servers and networking equipment, connecting customers’ servers with internet backbones and other value-added services (“Hosting services”), virtual private network services providing encrypted secured connection to public internet (“VPN services”) and public cloud service through strategic partnership with Microsoft (“Cloud services”).

On January 1, 2018, the Company adopted ASU No. 2014-09, Revenue from Contracts with Customers, (“ASC 606”), which supersedes the revenue recognition requirements in ASC Topic 605, Revenue Recognition, (“ASC 605”), using the modified retrospective transition method applied to those contracts which were not completed as of January 1, 2018. Results for reporting periods beginning after January 1, 2018 are presented under ASC 606, while prior period amounts have not been adjusted and continue to be reported in accordance with historic accounting under ASC 605. The impact of adopting the new revenue standard was not material to consolidated financial statements and there was no adjustment to beginning retained earnings on January 1, 2018.

Under ASC 606, an entity recognizes revenue as the Company satisfies a performance obligation when its customer obtains control of promised goods or services, in an amount that reflects the consideration that the entity expects to receive in exchange for those goods or services. To determine revenue recognition for arrangements that an entity determines are within the scope of ASC 606, the entity performs the following five steps: (i) identify the contract(s) with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price, including variable consideration, if any; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) the entity satisfies a performance obligation. The Company only applies the five-step model to contracts when it is probable that the entity will collect the consideration to which it is entitled in exchange for the goods or services it transfers to the customer.

Once a contract is determined to be within the scope of ASC 606 at contract inception, the Company reviews the contract to determine which performance obligations it must deliver and which of these performance obligations are distinct. The Company recognizes revenue based on the amount of the transaction price that is allocated to each performance obligation when that performance obligation is satisfied or as it is satisfied.

The Company is a principal and records revenue on a gross basis when the Company is primarily responsible for fulfilling the service, has discretion in establish pricing and controls the promised service before transferring that service to customers. Otherwise, the Company records revenue at the net amounts as commissions.

The Company derives revenue primary from the delivery of Hosting services, VPN services and Cloud services.

Hosting services are services that the Company dedicates data center space to house customers’ servers and networking equipment and provides tailored server administration services including operating system support and assistance with updates, server monitoring, server backup and restoration, server security evaluation, firewall services, and disaster recovery. The Company also provides interconnectivity services to connect customers with each other, internet backbones in China and other networks through Border Gateway Protocol, or BGP, network, or single-line, dual-line or multiple-line networks. Hosting services are typically provided to customers for a fixed amount over the contract service period and the related revenues are recognized on a straight-line basis over the term of the contract. For certain contracts where considerations are based on the usage of the Hosting services, the related revenues are recognized based on the consumption at the predetermined rate as the services are rendered throughout the contact term. The Company is a principal and records revenue for Hosting service on a gross basis.

VPN services are services that the Company extends customers’ private networks by setting up secure and dedicated connections through the public internet. VPN services are provided to customers for a fixed amount over the contract service period and revenue are recognized on a straight-line basis over the term of the contract. The Company is a principal and records revenue for VPN service on a gross basis.

Cloud services allow businesses to run their applications over the internet using the IT infrastructure. Revenue from Cloud services consisted of incentive revenue from Microsoft upon completion of certain conditions and a fixed percentage amount based on gross sales price generated from Cloud services provided to end customers. Cloud services are generally provided to end customers for a fixed amount over the contract period and the related revenues are recognized on a straight-line basis over the contract period. For certain contracts where considerations are based on the usage of the cloud resources, the related revenues are recognized based on the consumption at the predetermined rate as the services are rendered throughout the contract term. The Company records revenue for Cloud service on a net basis.

For certain arrangements, customers are required to pay the Company before the services are delivered. When either party to a revenue contract has performed, the Company recognizes a contract asset or a contract liability in the consolidated balance sheet, depending on the relationship between the Company’s performance and the customer’s payment. Contract liabilities were mainly related to fee received for Hosting services to be provided over the contract period, which were presented as deferred revenue on the consolidated balance sheets.

Deferred revenue represents the Company’s obligation to transfer the goods or services to a customer for which the Company has received consideration (or an amount of consideration is due) from the customer. As of December 31, 2017 and 2018, the Company has deferred revenue amounting up to RMB55,753 and RMB57,754 (US$8,400), respectively. The increase in deferred revenue as compared to the year ended December 31, 2017 is a result of the increase in consideration received from the customers. Revenue recognized from opening deferred revenue balance was RMB45,492 (US$6,617) for the year ended December 31, 2018.

(s)

Cost of revenues

Cost of revenues consists primarily of telecommunication costs, depreciation of the Company’s long-lived assets, amortization of acquired intangible assets, maintenance, data center rental expenses directly attributable to the provision of the IDC services, payroll and other related costs of operations.

(t)

Advertising expenditures

Advertising expenditures are expensed as incurred and are included in sales and marketing expenses, which amounted to RMB20,420, RMB7,773 and RMB7,968 (US$1,159) for the years ended December 31, 2016, 2017 and 2018, respectively.

(u)

Research and development expenses

Research and development expenses consist primarily of payroll and related personnel costs for routine upgrades and related enhancements of the Company’s services and network. Research and development expenses are expensed as incurred.

(v)

Government grants

Government grants are provided by the relevant PRC municipal government authorities to subsidize the cost of certain research and development projects. The amount of such government grants are determined solely at the discretion of the relevant government authorities and there is no assurance that the Company will continue to receive these government grants in the future. Government grants are recognized when it is probable that the Company will comply with the conditions attached to them, and the grants are received. When the grant relates to an expense item, it is recognized in the consolidated statement of operations over the period necessary to match the grant on a systematic basis to the costs that it is intended to compensate, as a reduction of the related operating expense. When the grant relates to an asset, it is recognized as deferred government grants and released to the consolidated statement of operations in equal amounts over the expected useful life of the related asset, when operational, as a reduction of the related depreciation expense.

(w)

Leases

Leases are classified at the inception date as either a capital lease or an operating lease. The Company did not enter into any leases whereby it is the lessor for any of the periods presented. As the lessee, a lease is a capital lease if any of the following conditions exists: a) ownership is transferred to the lessee by the end of the lease term, b) there is a bargain purchase option, c) the lease term is at least 75% of the property’s estimated remaining economic life, or d) the present value of the minimum lease payments at the beginning of the lease term is 90% or more of the fair value of the leased property to the lessor at the inception date. A capital lease is accounted for as if there was an acquisition of an asset and an incurrence of an obligation at the inception of the lease. The Company entered into capital leases for certain optical fiber, computer and network equipment and property in the years ended December 31, 2016, 2017 and 2018.

All other leases are accounted for as operating leases wherein rental payments are expensed on a straight-line basis over the periods of their respective lease terms. The Company leases office space and employee accommodation under operating lease agreements. Certain lease agreements contain rent holidays and escalating rent. Rent holidays and escalating rent are considered in determining the straight-line rent expense to be recorded over the lease term. The lease term begins on the date of initial possession of the lease property for purposes of recognizing lease expense on a straight-line basis over the term of the lease.

(x)

Capitalized interest

Interest expenses are capitalized if they are incurred during the acquisition, construction or production of a qualifying asset and such expenses could have been avoided if expenditures for these assets have not been made.

As a result of total interest expenses capitalized during the period, the interest expenses for the years ended December 31, 2016, 2017 and 2018, were as follows:


	For the years ended December 31,
	2016			2017			2018
	RMB			RMB			RMB			US$
Interest expense and amortization cost of bonds		113,367			63,354			150,098			21,831
Interest expense on bank borrowings		46,377			87,916			19,395			2,820
Interest expense on capital lease		66,687			63,757			79,935			11,626

Total interest expenses		226,431			215,027			249,428			36,277
Less: Total interest expenses capitalized		(27,842	)		(29,714	)		(13,362	)		(1,943	)

Interest expenses, net		198,589			185,313			236,066			34,334

(y)

Income taxes

The Company accounts for income taxes using the liability method. Under this method, deferred tax assets and liabilities are determined based on the difference between the financial reporting and tax bases of assets and liabilities using enacted tax rates that will be in effect in the period in which the differences are expected to reverse. The Company records a valuation allowance against deferred tax assets if, based on the weight of available evidence, it is more-likely-than-not that some portion, or all, of the deferred tax assets will not be realized. The effect on deferred taxes of a change in tax rates is recognized in income in the period that includes the enactment date of the change in tax rate.

The Company applies ASC Topic 740, Accounting for Income Taxes, (“ASC 740”), to account for uncertainty in income taxes. ASC 740 prescribes a recognition threshold a tax position is required to meet before being recognized in the financial statements.

The Company has elected to classify interest and penalties related to unrecognized tax benefits, if and when required, as part of “income tax expenses” in the consolidated statements of operations.

The Company adopted ASU No. 2015-17, Income Taxes (Topic 740): Balance Sheet Classification of Deferred Taxes, (“ASU 2015-17”), to classify all deferred income tax assets and liabilities as non-current on the consolidated balance sheets.

(z)

Share-based compensation

Share options and Restricted Share Units (“RSUs”) granted to employees are accounted for under ASC Topic 718, Compensation—Stock Compensation, (“ASC 718”), which requires that share-based awards granted to employees be measured based on the grant date fair value and recognized as compensation expenses over the requisite service period and/or performance period (which is generally the vesting period) in the consolidated statements of operations.

The Company has elected to recognize compensation expenses using the straight-line method for share-based awards granted with service conditions that have a graded vesting schedule. For share-based awards granted with performance conditions, the Company recognizes compensation expenses using the accelerated method. The Company commences recognition of the related compensation expenses if it is probable that the defined performance condition will be met. To the extent that the Company determines that it is probable that a different number of share-based awards will vest depending on the outcome of the performance condition, the cumulative effect of the change in estimate is recognized in the period of change. For share-based awards with market conditions, the probability to achieve market conditions is reflected in the grant date fair value. The Company recognized the related compensation expenses when the requisite service is rendered using the accelerate method.

For the performance bonuses that the employees can elect to settle in cash and/or restricted shares at an agreed premium of the Company (“Share-Settled Bonus”), the Company estimates the portion of the arrangement to be settled in shares based on its past settlement practices and classifies such portion as a liability in accordance with ASC Topic 480, Distinguishing Liabilities from Equity, (“ASC 480”). The Company remeasures the fair value of such liability at each reporting period end through earnings until the underlying shares were approved and granted to the employees and accounted for the granted restricted shares unit as equity award. The original cash bonus amount continues to be classified as a liability within “Accrued expenses and other payables” in the consolidated balance sheets until the end of the six months’ lock-up period as such amounts will be paid to the employees in cash upon the termination of their employment. The fair value of the premium will be reclassified to additional paid in capital and recognized over the remaining lock-up period using the accelerated method, respectively.

A cancellation of the terms or conditions of an equity award under original award in exchange for a new award should be treated as modification. The compensation costs associated with the modified awards are recognized if either the original vesting conditions or the new vesting conditions have been achieved. Total recognized compensation cost for the awards is at least equal to the fair value of the original awards at the grant date unless at the date of the modification the performance or service conditions of the original awards are not expected to be satisfied. The incremental compensation cost is measured as the excess of the fair value of the replacement awards over the fair value at the modification date. Therefore, in relation to the modified awards, the Company recognizes share-based compensation over the vesting periods of the new awards, which comprises (i) the amortization of the incremental portion of share-based compensation over the remaining vesting term, and (ii) any unrecognized compensation cost of original awards, using either the original term or the new term, whichever results in higher expenses for each reporting period. For modification of a liability award that remains a liability after modification, the liability award continues to be remeasured at fair value at each reporting date.

On April 15, 2016 (“the Modification date”), the Company made revisions to the Share-Settled Bonus to remove the agreed premium and six month lock-up period for the employees above a specified level and the option to settle in share for the employees below a specified level. The modified awards remain as liabilities in accordance with ASC 718 as the Company can only settle the Share-Settled Bonus by issuing variable number of shares until the settlement date or in cash. In January 2017, the Company made revisions to the Share-Settled Bonus to remove the option to settle bonus accrued in 2017. For the Share-Settled Bonus accrued in 2016 which were elected to be settled in shares, the Company issued shares to settle all the Share-Settled Bonus as of December 31, 2017.

On November 26, 2016, the Board approved a new incentive program to replace unvested RSUs to certain individuals with a new bonus scheme which will be settled by issuing a variable number of shares with a fair value equal to fixed dollar amount on the settlement date. The modification was treated as an equity to liability modification in accordance with ASC 718. The Company remeasures the fair value of such liability at each reporting period end through earnings until the actual settlement date, which is the date when the number of underlying shares were fixed and recorded the incremental cost over the remaining vesting term and the unrecognized compensation of original awards using the new term.

The Company adopted ASU No. 2016-09, Improvements to Employee Share-Based Payment Accounting, (“ASU 2016-09”), and elected to account for forfeitures as they occur.

(aa)

Loss per share

In accordance with ASC Topic 260, Earnings per Share, (“ASC 260”), basic loss per share is computed by dividing net loss attributable to ordinary shareholders by the weighted average number of unrestricted ordinary shares outstanding during the year. Diluted loss per share is calculated by dividing net loss attributable to ordinary shareholders as adjusted for the effect of dilutive ordinary equivalent shares, if any, by the weighted average number of ordinary and dilutive ordinary equivalent shares outstanding during the period. Contingently issuable shares, including performance-based share awards and contingent purchase considerations to be settled in shares, are included in the computation of basic earnings per share only when there is no circumstance under which those shares would not be issued. Contingently issuable shares are included in the denominator of the diluted loss per share calculation as of the beginning of the period or as of the inception date of the contingent share arrangement, if later, only when dilutive and when all the necessary conditions have been satisfied as of the reporting period end. For contracts that may be settled in ordinary shares or in cash at the election of the Company, share settlement is presumed, pursuant to which incremental shares relating to the number of shares that would be required to settle the contract are included in the denominator of diluted loss per share calculation if the effect is more dilutive. For the contracts that may be settled in ordinary shares or in cash at the election of the counterparty, the more dilutive option of cash or share settlement is used for the purposes of diluted loss per share calculation, pursuant to which share settlement requires the number of shares that would be required to settle the contract be included in the denominator whereas cash settlement requires an adjustment to be made to the numerator for any changes in income or loss that would result as if the contract had been classified as an asset or a liability for accounting purposes during the period for a contract that is classified as equity for accounting purposes, if the effect is more dilutive. Ordinary equivalent shares consist of the ordinary shares issuable upon the exercise of the share options, using the treasury stock method. Ordinary share equivalents are excluded from the computation of diluted loss per share if their effects would be anti-dilutive.

(bb)

Share repurchase program

Pursuant to the Board of Directors’ resolutions on August 18, 2016, the Company’s management is authorized to repurchase, in one or more tranches, up to an aggregate of US$200,000 of its own outstanding shares (including shares represented by ADSs) (each such transaction a “Repurchase”) over a period of 12 months starting from June 29, 2016.

The Company accounted for the repurchased shares as Treasury Stock at cost in accordance to ASC Subtopic 505-30, Treasury Stock, (“ASC 505-30”), and the share repurchase is shown separately in the consolidated statement of shareholder’s equity, as the Company has not yet decided on the ultimate disposition of those ADSs acquired. When the Company uses the treasury stock to settle the share consideration for the acquisitions (Note 18), the difference between the fair value at settlement date and the repurchase price is debited into additional paid-in capital. When the Company decides to retire the treasury stock, the difference between the original issuance price and the repurchase price is debited into accumulated deficit.

For the years ended December 31, 2016, 2017 and 2018, the Company repurchased 815,525, 3,448,482 and nil ADSs for a consideration of RMB42,665, RMB133,126 and nil, respectively.

(cc)

Comprehensive loss

Comprehensive loss is defined as the decrease in equity of the Company during a period from transactions and other events and circumstances excluding transactions resulting from investments by owners and distributions to owners. Accumulated other comprehensive (loss) income of the Company includes foreign currency translation adjustments related to the Company and its overseas subsidiaries, whose functional currency is US$.

(dd)

Segment reporting

In accordance with ASC Topic 280, Segment Reporting, (“ASC 280”), the Company historically had only one single reportable segment since the Company’s chief executive officer, who has been identified as the Company’s chief operating decision-maker (“CODM”) formerly relied on the consolidated results of operations when making decisions on allocating resources and assessing performance of the Company. On October 1, 2016, the Company changed its reportable segments as the CODM reviewed the operating result of two different services in order to allocate resources and assess performance of the Company. The operations of the Company are organized into two segments, consisting of the hosting and related services and managed network services. Hosting and related services business focuses primarily on colocation, interconnectivity, cloud, VPN, hybrid IT and other value-added services. Managed network services focuses on businesses that primarily utilize bandwidth such as content delivery network (“CDN”) service, hosting area network services and last-mile wired broadband service.

In September 2017, the Company disposed of WiFire Entities and Aipu Group, which are primarily engaged in the managed network services. After the disposals, the CODM reviews the operation results on the Company basis. As of December 31, 2017 and 2018, the Company only had one reporting segment.

(ee)

Employee benefits

The full-time employees of the Company’s PRC subsidiaries are entitled to staff welfare benefits including medical care, housing fund, pension benefits and unemployment insurance, which are governmental mandated defined contribution plans. These entities are required to accrue for these benefits based on certain percentages of the employees’ respective salaries, subject to certain ceilings, in accordance with the relevant PRC regulations, and make cash contributions to the state-sponsored plans out of the amounts accrued.

(ff)

Comparatives

Certain items reported in the prior year’s consolidated financial statements have been reclassified to conform with the current year’s presentation.

(gg)

Recent accounting pronouncements

In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842), (“ASU 2016-02”), which requires a lessee to recognize a lease liability and a right-of-use asset for all leases with lease terms of more than 12 months. This guidance is effective for annual reporting periods beginning after December 15, 2018, including interim periods within those years, and early adoption is permitted. In January 2018, the FASB issued ASU No. 2018-01, Leases: Land Easement Practical Expedient, (“ASU 2018-01”), which provides an optional transition practical expedient for land easements. The effective date of the transition requirements for the amendment is the same as the effective date and transition requirements in ASU 2016-02. Subsequently, the FASB issued ASU No. 2018-10 Codification Improvements to Topic 842, Leases, (“ASU 2018-10”), which clarifies certain aspects of the guidance issued in ASU 2016-02; and ASU No. 2018-11, Leases (Topic 842): Targeted Improvements, (“ASU 2018-11”), which provides an additional transition method and a practical expedient for separating components of a contract for lessors. ASU 2016-02 modifies existing guidance for off balance sheet treatment of lessees’ operating leases by requiring lessees to recognize lease assets and lease liabilities. Under ASU 2016-02, lessor accounting is largely unchanged. ASU 2018-10 clarifies certain provisions and correct unintended applications of the guidance such as the application of implicit rate, lessee reassessment of lease classification, and certain transition adjustments that should be recognized to earnings rather than to stockholders’ equity. ASU 2018-11 provides an alternative transition method and practical expedient for separating contract components for the adoption of Topic 842. ASU 2018-11, ASU 2018-10, and ASU 2016-02 (collectively, “the new lease standards”) are effective for public business entities for annual reporting periods and interim periods within those years beginning after December 15, 2018. These new lease standards become effective for the Company on January 1, 2019. The Company will adopt this standard effective January 1, 2019 using the modified retrospective method, and chose to apply the new standard as of the effective date and will not restate comparable period. Consequently, all of the Company’s operating lease commitments were recognized as lease liabilities, with correspondingright-of-use assets, based on the present value of the remaining minimum rental payments under current leasing standards for existing operating leases. The Company will elect the package of practical expedients permitted under the transition guidance within the new standard, which permits the Company not to reassess under the new standard its prior conclusions about lease identification, lease classification and initial direct costs. The Company’s operating leases mainly related to offices and data center space will be subject to ASU 2016-02 and right-of-use assets and lease liabilities will be recognized on the Company’s consolidated balance sheet. The Company currently believes the most significant change will be related to the recognition of right-of-use assets and lease liabilities on the Company’s balance sheet for operating leases. The Company does not expect any material impact on net assets and the consolidated statement of comprehensive loss as a result of adopting the new standards.

In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments—Credit Losses (Topic 326), Measurement of Credit Losses on Financial Instruments, (“ASU 2016-13”). ASU 2016-13 changes the impairment model for most financial assets and certain other instruments. The standard will replace “incurred loss” approach with an “expected loss” model for instruments measured at amortized cost. For available-for-sale debt securities, entities will be required to record allowances rather than reduce the carrying amount, as they do today under the other-than-temporary impairment model. The standard is effective for public business entities for annual periods beginning after December 15, 2019, and interim periods therein. Early adoption is permitted. The Company is evaluating the effect that this guidance will have on its consolidated financial statements.

In August 2018, the FASB issued ASU No. 2018-13, Fair Value Measurement, (“ASU 2018-13”). ASU 2018-13 modifies the disclosure requirements for fair value measurements by removing, modifying, or adding certain disclosures. The amendments in ASU 2018-13 will be effective for the Company beginning after January 1, 2020 including interim periods within the year. Early adoption is permitted. An entity is permitted to early adopt any removed or modified disclosures upon issuance of ASU No. 2018-13 and delay adoption of the additional disclosures until their effective date. The Company is evaluating the impact of adopting this new standard will have on its consolidated financial statements.

Concentration of Risks

12 Months Ended

Dec. 31, 2018

Risks and Uncertainties [Abstract]

Concentration of Risks

3.	CONCENTRATION OF RISKS

(a)

Credit risk

Financial instruments that potentially subject the Company to significant concentrations of credit risk consist primarily of cash and cash equivalents, short-term investments, accounts receivable, other receivables and amounts due from related parties. As of December 31, 2017 and 2018, the aggregate amount of cash and cash equivalents, restricted cash and short-term investments of RMB640,001 and RMB1,131,588 (US$164,583), respectively, were held at major financial institutions located in the PRC, and US$323,434 and US$258,083 (RMB1,774,447), respectively, were deposited with major financial institutions located outside the PRC. Management believes that these financial institutions are of high credit quality and continually monitors the credit worthiness of these financial institutions. Historically, deposits in Chinese banks are secure due to the state policy on protecting depositors’ interests. However, China promulgated a new Bankruptcy Law in August 2006 that came into effect on June 1, 2007, which contains a separate article expressly stating that the State Council may promulgate implementation measures for the bankruptcy of Chinese banks based on the Bankruptcy Law. Under the new Bankruptcy Law, a Chinese bank may go into bankruptcy. In addition, since China’s concession to the World Trade Organization, foreign banks have been gradually permitted to operate in China and have been significant competitors against Chinese banks in many aspects, especially since the opening of the Renminbi business to foreign banks in late 2006. Therefore, the risk of bankruptcy of those Chinese banks in which the Company has deposits has increased. In the event of bankruptcy of one of the banks which holds the Company’s deposits, the Company is unlikely to claim its deposits back in full since the bank is unlikely to be classified as a secured creditor based on PRC laws.

(b)

Business, supplier, customer, and economic risk

The Company participates in a relatively dynamic and competitive industry that is heavily reliant operation excellence of the services. The Company believes that changes in any of the following areas could have a material adverse effect on the Company’s future financial position, result of operations or cash flows:

(i) Business Risk—Third parties may develop technological or business model innovations that address data center and network requirements in a manner that is, or is perceived to be, equivalent or superior to the Company’s services. If competitors introduce services that compete with, or surpass the quality, price or performance of the Company’s services, the Company may be unable to renew its agreements with existing customers or attract new customers at the prices and levels that allow the Company to generate reasonable rates of return on its investment.

(ii) Supplier Risk—The Company’s operations are dependent upon bandwidth and cabinet capacity provided by the third-party telecom carriers. There can be no assurance that the Company will be able to secure the cabinet and bandwidth supply from the third-party telecom carriers, neither the Company is adequately prepared for unexpected increases in bandwidth demands by its customers. The communications capacity the Company has leased, include cabinet and bandwidth, may become unavailable for a variety of reasons, such as physical interruption, technical difficulties, contractual disputes, or the financial health of its third-party providers. Any failure of these network providers to provide the capacity the Company requires may result in a reduction in, or interruption of, service to its customers. A significant portion of the Company’s total bandwidth and cabinet resources are purchased from its five largest suppliers, who collectively accounted for 19%, 21% and 19% of the Company’s total bandwidth and cabinet resources for the years ended December 31, 2016, 2017 and 2018, respectively.

(iii) Customer Risk—The success of the Company’s business going forward will rely in part on Group’s ability to continue to obtain and expand business from existing customers while also attracting new customers. The Company has a diversified base of customers covering its services and the revenue from the largest single customer accounted for less than 12% of the Company’s total net revenues in the year ended December 31, 2018. Certain customers are local subsidiaries of a telecommunication carrier in China, which the Company views as separate customers as it negotiates with, maintain and support each of these entities given that each of them has the separate decision-making authority and services procurement budget. None of these customers on a stand-alone basis contributed more than 3% of the Company’s revenues in any given year but in the aggregate, they contributed approximately 4%, 2% and 4% of the Company’s total revenues for the years ended December 31, 2016, 2017 and 2018, respectively.

(iv) Political, economic and social uncertainties—The Company’s operations could be adversely affected by significant political, economic and social uncertainties in the PRC. Although the PRC government has been pursuing economic reform policies for more than 20 years, no assurance can be given that the PRC government will continue to pursue such policies or that such policies may not be significantly altered, especially in the event of a change in leadership, social or political disruption or unforeseen circumstances affecting the PRC political, economic and social conditions. There is also no guarantee that the PRC government’s pursuit of economic reforms will be consistent or effective.

(v) Regulatory restrictions—The applicable PRC laws, rules and regulations currently prohibit foreign ownership of companies that provide internet related services, including hosting and related services. Accordingly, the Company’s subsidiary, 21Vianet China, is currently ineligible to apply for the required licenses for providing IDC services in China. As a result, the Company operates its IDC services in the PRC through its Consolidated VIEs which holds the licenses and permits required to provide IDC services in the PRC. The PRC Government may also choose at anytime to block access to certain website operators which could also materially impact the Company’s ability to generate revenue.

(c)

Currency convertibility risk

The Company transacts substantially all its business in RMB, which is not freely convertible into foreign currencies. On January 1, 1994, the PRC government abolished the dual-rate system and introduced a single rate of exchange as quoted daily by the People’s Bank of China (the “PBOC”). However, the unification of the exchange rates does not imply that the RMB may be readily convertible into US$ or other foreign currencies. All foreign exchange transactions continue to take place either through the PBOC or other banks authorized to buy and sell foreign currencies at the exchange rates quoted by the PBOC. Approval of foreign currency payments by the PBOC or other institutions requires submitting a payment application form together with suppliers’ invoices, shipping documents and signed contracts.

(d)

Foreign currency exchange rate risk

From July 21, 2005, the RMB is permitted to fluctuate within a narrow and managed band against a basket of certain foreign currencies. The depreciation (appreciation) of the RMB against US$ was approximately 6.8%, (5.8)% and 5.0% in the years ended December 31, 2016, 2017 and 2018, respectively.

(e)

Interest rate risk

The Company is exposed to interest rate risk on its interest-bearing assets and liabilities. As part of its asset and liability risk management, the Company reviews and takes appropriate steps to manage its interest rate exposures on its interest-bearing assets and liabilities. The Company has not been exposed to material risks due to changes in market interest rates, and not used any derivative financial instruments to manage the interest risk exposure during the periods presented.

Disposal of Subsidiaries

12 Months Ended

Dec. 31, 2018

Discontinued Operations and Disposal Groups [Abstract]

Disposal of Subsidiaries

4.	DISPOSAL OF SUBSIDIARIES

Disposals

in 2017

In September 2017, six wholly-owned subsidiaries engaged in CDN, hosting area network services and route optimization businesses, namely Guangzhou Gehua Network Technology Development Co., Ltd., CYSD, Zhiboxintong (Beijing) Network Technology Co., Ltd., WiFire BJ, BJ Fastweb and SH Guotong and Sichuan Aipu Network Co., Ltd. (“SC Aipu”) and its affiliates (collectively, the “Aipu Group”), which are engaged in the last-mile broadband business, were deconsolidated by the Company.

Disposal of WiFire Entities

In September 2017, the Company transferred 66.67% of the equity interest in the WiFire Entities for a nominal consideration of RMB6 yuan for each of the WiFire Entities to Beijing TUS Yuanchuang Technology Development Co., Ltd., a wholly-owned subsidiary of Tus-Holdings, the controlling shareholder of the Company. Upon completion of disposal, the Company accounted for the remaining 33.33% of equity interest in the WiFire Entities as equity method investments under ASC 323-10 for its ability to exercise significant influence in the WiFire Entities.

Disposal

of Aipu Group

In September 2017, the Company transferred two shares in SC Aipu to Mr. Jian Li, the Co-CEO and a director of SC Aipu, for a nominal consideration of RMB1 yuan. Immediately after the disposal, the Company’s ownership in SC Aipu changed from 50% equity interest plus one share to 50% equity interest minus one share and lost control. The Company accounted for the remaining equity interest as equity method investment for its ability to exercise significant influence in the Aipu Group.

Subsequently in December 2017, the Company transferred all the remaining 50% equity interest minus one share in SC Aipu to Tibet Xingtao Culture Communications Co., Ltd., one of SC Aipu’s shareholders, for a nominal consideration of RMB1 yuan.

In addition to the impairment losses for long-lived assets and goodwill of RMB401,808 and RMB766,440, respectively, recognized in relation to Wifire Entities and Aipu Group before the disposal, the Company recognized a gain on disposal of WiFire Entities and Aipu Group of RMB497,036 for the year ended December 31, 2017.

Accounts and Notes Receivable, Net

12 Months Ended

Dec. 31, 2018

Receivables [Abstract]

Accounts and Notes Receivable, Net

5.	ACCOUNTS AND NOTES RECEIVABLE, NET

Accounts and notes receivable and the allowance for doubtful debt consisted of the following:


	As of December 31,
	2017			2018
	RMB			RMB			US$
Accounts receivable		526,747			592,669			86,200
Notes receivable		2,720			2,606			379
Allowance for doubtful debt		(73,656	)		(70,970	)		(10,322	)

		455,811			524,305			76,257

As of December 31, 2017 and 2018, all accounts and notes receivable were due from third party customers. An analysis of the allowance for doubtful debt was as follows:


	For the years ended December 31,
	2017			2018
	RMB			RMB			US$
Balance at beginning of the year		80,910			73,656			10,712
Additional provision charged to expense		69,553			315			46
Write-off of accounts receivable		(19,766	)		(3,001	)		(436	)
Provision included in disposed subsidiaries		(57,041	)		—			—

Balance at end of the year		73,656			70,970			10,322

- Definition

The entire disclosure for claims held for amounts due a entity, excluding financing receivables. Examples include, but are not limited to, trade accounts receivables, notes receivables, loans receivables. Includes disclosure for allowance for credit losses.

+ References + Details

Short-Term Investments

12 Months Ended

Dec. 31, 2018

Investments Schedule [Abstract]

Short-Term Investments

6.	SHORT-TERM INVESTMENTS

Short-term investments consisted of the following as of December 31, 2017 and 2018:

As of December 31,

2017

2018

RMB

US$

Time deposits

548,890

245,014

35,636

The Company recorded interest income related to its short-term investments amounting to RMB1,148, RMB4,021 and RMB7,303 (US$1,062) for the years ended December 31, 2016, 2017 and 2018, respectively, in the consolidated statements of operations.

Prepaid Expenses and Other Current Assets

12 Months Ended

Dec. 31, 2018

Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]

Prepaid Expenses and Other Current Assets

7.	PREPAID EXPENSES AND OTHER CURRENT ASSETS

Prepaid expenses and other current assets consisted of the following:


	As of December 31,
	2017		2018
	RMB		RMB		US$
Prepaid expenses		380,869		565,710		82,279
Staff advances		6,735		10,730		1,561
Interest receivables		17,644		12,037		1,751
Tax recoverables		376,642		421,654		61,327
Deposits		30,669		39,971		5,814
Prepayment for share repurchase plan		42,710		—		—
Loan to third parties		60,805		58,909		8,567
Other receivables		17,676		48,729		7,086

		933,750		1,157,740		168,385

Prepaid expenses mainly represented the unamortized portion of prepayments made to Microsoft for the cloud computing services, and the prepayments to telecommunication operators for bandwidth, data centers or cabinets.

Property and Equipment, Net

12 Months Ended

Dec. 31, 2018

Property, Plant and Equipment [Abstract]

Property and Equipment, Net

8.	PROPERTY AND EQUIPMENT, NET

Property and equipment, including those held under capital leases, consisted of the following:


	As of December 31,
	2017			2018
	RMB			RMB			US$
At cost:
Property		467,312			753,319			109,566
Leasehold improvements		789,734			932,896			135,684
Computer and network equipment		2,681,759			3,260,336			474,196
Optical fibers		142,723			142,723			20,758
Office equipment		12,671			24,390			3,547
Motor vehicles		1,891			1,841			268

		4,096,090			5,115,505			744,019
Less: Accumulated depreciation		(1,326,511	)		(1,870,640	)		(272,073	)

		2,769,579			3,244,865			471,946
Construction-in-progress		549,845			786,377			114,374

		3,319,424			4,031,242			586,320

Depreciation expense was RMB480,105, RMB523,500 and RMB566,491 (US$82,393) for the years ended December 31, 2016, 2017 and 2018, respectively, and were included in the following captions:


	For the years ended December 31,
	2016		2017		2018
	RMB		RMB		RMB		US$
Cost of revenues		397,014		458,655		520,791		75,746
Sales and marketing expenses		3,759		3,188		986		144
General and administrative expenses		45,746		41,675		28,727		4,178
Research and development expenses		33,586		19,982		15,987		2,325

		480,105		523,500		566,491		82,393

The carrying amounts of the Company’s property and equipment held under capital leases at respective balance sheet dates were as follows:


	As of December 31,
	2017			2018
	RMB			RMB			US$
Property		365,353			365,353			53,138
Computer and network equipment		497,532			719,676			104,673
Optical fibers		142,723			142,723			20,758

		1,005,608			1,227,752			178,569
Less: Accumulated depreciation		(262,601	)		(291,579	)		(42,408	)

		743,007			936,173			136,161
Construction-in-progress		130,192			576,022			83,779

		873,199			1,512,195			219,940

Depreciation expense of property, computer and network equipment and optical fibers under capital leases was RMB100,157, RMB92,920 and RMB170,264 (US$24,764), for the years ended December 31, 2016, 2017 and 2018, respectively.

The carrying amounts of property and equipment pledged by the Company to secure banking borrowings (Note 13) granted to the Company at the respective balance sheet dates were as follows:


	As of December 31,
	2017		2018
	RMB		RMB		US$
Property		143,893		140,393		20,419
Computer and network equipment		200,954		146,159		21,258
Office equipment		85		44		6

Intangible Assets, Net

12 Months Ended

Dec. 31, 2018

Goodwill and Intangible Assets Disclosure [Abstract]

Intangible Assets, Net

9.	INTANGIBLE ASSETS, NET

The following table presented the Company’s intangible assets as of the respective balance sheet dates:


	Purchased software			Radio spectrum license			Network use right			Contract backlog			Customer relationships			Licenses			Supplier relationships			Trade names			Platform software			Non-compete agreements			Internal- use software			Property management relationship			Total
	RMB			RMB						RMB			RMB			RMB			RMB			RMB			RMB			RMB			RMB			RMB			RMB
Intangible assets, net January 1, 2017		73,445			91,568			15,834			18,338			412,775			12,557			88,443			168,385			3,924			8,903			40,006			43,163			977,341
Additions		11,073			—			—			—			—			—			—			—			—			—			9,238			—			20,311
Disposals		(5,973	)		—			(15,086	)		—			(134,706	)		(4,000	)		(7,227	)		(37,270	)		—			(4,297	)		(41,660	)		(30,178	)		(280,397	)
Foreign currency translation difference		(905	)		(7,781	)		—			—			—			—			—			—			—			—			—			—			(8,686	)
Amortization expense		(27,011	)		(6,646	)		(748	)		(6,588	)		(52,992	)		(757	)		(19,304	)		(12,217	)		(3,241	)		(3,347	)		(5,524	)		(5,227	)		(143,602	)
Impairment		—			—			—			—			(87,195	)		(3,532	)		(41,768	)		(22,494	)		—			(1,105	)		—			(7,758	)		(163,852	)

Intangible assets, net December 31, 2017		50,629			77,141			—			11,750			137,882			4,268			20,144			96,404			683			154			2,060			—			401,115

Additions		18,744			—			—			—			—			—			—			—			—			—			6,093			—			24,837
Disposals		(6,772	)		—			—			—			—			—			—			—			—			—			—			—			(6,772	)
Foreign currency translation difference		364			3,884			—			—			—			—			—			—			—			—			—			—			4,248
Amortization expense		(15,711	)		(8,117	)		—			(6,588	)		(24,921	)		(385	)		(3,074	)		(5,813	)		(683	)		(110	)		(2,713	)		—			(68,115	)

Intangible assets, net December 31, 2018		47,254			72,908			—			5,162			112,961			3,883			17,070			90,591			—			44			5,440			—			355,313

Intangible assets, net December 31, 2018 (US$)		6,873			10,604			—			751			16,429			565			2,483			13,176			—			6			791			—			51,678

Contract backlog relate to the order placed by the customers that have yet to be delivered at the acquisition date. Customer relationships relate to the relationships that arose as a result of existing customer agreements acquired and is derived from the estimated net cash flows that are expected to be derived from the expected renewal of these existing customer agreements after subtracting the estimated net cash flows from other contributory assets. Licenses mainly represented the telecommunication service license in relation to virtual private network services. Supplier relationships relate to the relationships that arose as a result of existing bandwidth supply agreements with certain network operators, which were valued using a replacement cost method given the relative ease of replacement. Trade names mainly relate to the trade names of Dermot Entities.

The intangible assets are amortized using the straight-line method, which is the Company’s best estimate of how these assets will be economically consumed over their respective estimated useful lives ranging from 1 to 20 years.

Amortization expenses were approximately RMB183,964, RMB143,602 and RMB68,115 (US$9,907) for the years ended December 31, 2016, 2017 and 2018, respectively.

The annual estimated amortization expenses for the intangible assets for each of the next five years are as follows:


	RMB		US$
2019		56,567		8,227
2020		47,232		6,870
2021		45,005		6,545
2022		41,088		5,976
2023		28,322		4,120

		218,214		31,738

Land Use Rights, Net

12 Months Ended

Dec. 31, 2018

Text Block [Abstract]

Land Use Rights, Net

10.

LAND USE RIGHTS, NET

Land use rights held by the Company are amortized over the remaining term of the respective land use rights certificates.


	As of December 31,
	2017			2018
	RMB			RMB			US$
Cost		172,520			159,494			23,197
Accumulated amortization		(8,849	)		(12,001	)		(1,745	)

Land use rights, net		163,671			147,493			21,452

The carrying amounts of land use rights pledged by the Company to secure banking borrowings (Note 13) granted to the Company at the respective balance sheet dates were as follows:

As of December 31,

2017

2018

RMB

US$

Land use rights

16,818

16,403

2,386

Goodwill

12 Months Ended

Dec. 31, 2018

Goodwill and Intangible Assets Disclosure [Abstract]

Goodwill

11.

GOODWILL

The changes in the carrying amount of goodwill were as follows:


	For the years ended December 31,
	2016		2017			2018
	RMB		RMB			RMB		US$
Balance at beginning of the year		1,755,970		1,755,970			989,530		143,921
Impairment		—		(766,440	)		—		—

Balance at end of the year		1,755,970		989,530			989,530		143,921

As of December 31, 2016, goodwill allocated to the reporting units of hosting and related services and managed network services was RMB989,530 and RMB766,440, respectively.

In September 2017, goodwill included in managed network services reporting unit was fully impaired immediately before disposal of WiFire Entities and Aipu Group. As of December 31, 2017, no impairment loss of goodwill in hosting and related services was recorded.

As of December 31, 2018, the Company has performed a qualitative assessment for hosting and related services and no impairment loss was recorded for this year.

Long-Term Investments

12 Months Ended

Dec. 31, 2018

Investments Schedule [Abstract]

Long-Term Investments

12.

LONG-TERM INVESTMENTS

The Company’s long-term investments consisted of the following:


	As of December 31,
	2017		2018
	RMB		RMB		US$
Equity investments without readily determinable fair values		57,567		51,410		7,477
Equity method investments		450,822		490,376		71,322
Available-for-sale debt investments		2,537		2,537		369

		510,926		544,323		79,168

Equity investments without readily determinable fair values

The Company disposed an equity investment without readily determinable fair values with a consideration of RMB26,653 (US$3,877) in 2018. The investment income comprised of dividend income of RMB1,821 and RMB406 (US$59), and disposal gain of nil and RMB20,496 (US$2,981) for the years ended December 31, 2017 and 2018, respectively.

The Company recorded an impairment loss of long-term investment amounting nil, RMB20,258 and nil for the years ended December 31, 2016, 2017 and 2018, respectively.

Equity method investments:


	As of December 31, 2016							Increase (decrease) during the year ended December 31, 2017					As of December 31, 2017
	Cost of investments		Share equity gain (loss)			Investments in equity investee		Cost of investments		Share equity gain (loss)			Cost of investments		Share equity gain (loss)			Investments in equity investee
	RMB		RMB			RMB		RMB		RMB			RMB		RMB			RMB
Yizhuang Fund		101,000		85,148			186,148		—		90,888			101,000		176,036			277,036
Unis Tech		49,000		(285	)		48,175		—		(12,676	)		49,000		(12,961	)		36,039
Shihua DC Holdings		—		—			—		147,176		(9,429	)		147,176		(9,429	)		137,747
WiFire Entities		—		—			—		15,000		(15,000	)		15,000		(15,000	)		—

		150,000		84,863			234,863		162,176		53,783			312,176		138,646			450,822


	As of December 31, 2017							Increase (decrease) during the year ended December 31, 2018								As of December 31, 2018
	Cost of investments		Share equity gain (loss)			Investments in equity investee		Cost of investments			Share equity loss			Disposal gain		Cost of investments		Share equity gain (loss)			Disposal gain		Investments in equity investee		Investments in equity investee
	RMB		RMB			RMB		RMB			RMB			RMB		RMB		RMB			RMB		RMB		US$
Yizhuang Fund		101,000		176,036			277,036		—			(150,355	)		—		101,000		25,681			—		126,681		18,425
Unis Tech		49,000		(12,961	)		36,039		(49,000	)		(3,548	)		16,509		—		(16,509	)		16,509		—		—
Shihua DC Holdings		147,176		(9,429	)		137,747		219,447			(24,229	)		—		366,623		(33,658	)		—		332,965		48,428
Jingliang Inter Cloud		—		—			—		6,000			(34	)		—		6,000		(34	)		—		5,966		868
Jingliang Century Cloud		—		—			—		4,000			—			—		4,000		—			—		4,000		582
Huaye Cloud		—		—			—		23,333			(6,319	)		—		23,333		(6,319	)		—		17,014		2,474
ZJK Energy		—		—			—		5,907			(2,157	)		—		5,907		(2,157	)		—		3,750		545
WiFire Entities		15,000		(15,000	)		—		—			—			—		15,000		(15,000	)		—		—		—

		312,176		138,646			450,822		209,687			(186,642	)		16,509		521,863		(47,996	)		16,509		490,376		71,322

In April 2012, the Company through its subsidiary, 21Vianet Beijing, entered into an agreement to invest in the Yizhuang Venture Investment Fund (“Yizhuang Fund”) as a limited partner with an amount of RMB50,500. In December 2013, the Company made the second tranche of investment of another amount of RMB50,500 in the Yizhuang Fund, and held 27.694% of the investee as of December 31, 2016, 2017 and 2018. Given the Company holds more than three percent interest in the Yizhuang Fund as a limited partner, the investment is accounted for under the equity method as prescribed in ASC Subtopic 323-10, Investments—Equity Method, (“ASC 323-10”).

In June 2016, the Company through its subsidiary, 21Vianet Beijing, and a related company jointly set up Unisplendour-Vianet Technology Inc. (“Unis Tech”). The Company injected capital of RMB49,000 to acquire 49% of equity interest in Unis Tech with the ability to exercise significant influence. In March 2018, the Company disposed all its equity interests in Unis Tech with a total cash consideration of RMB49,000 (US$7,127) and recognized investment loss with an amount of RMB3,548 (US$516) and disposal gain with an amount of RMB16,509 (US$2,401).

In March 2017, the Company through its subsidiary, 21Vianet HK, and a third company jointly set up Shihua DC Holdings Inc. (“Shihua DC Holdings”). The Company injected capital of RMB147,176 to acquire 49% of equity interest in Shihua DC Holdings with the ability to exercise significant influence. In the year of 2018, the Company increased the capital injection with the amount of RMB219,447 (US$31,917) on a pro rata basis.

In September 2017, after the disposal of 66.67% equity interest in the WiFire Entities, the Company held the remaining 33.33% equity interest in the WiFire Entities, which is accounted for equity method investment at fair value of RMB6 yuan at the disposal date. In December 2017, the Company injected capital of RMB15,000 in the WiFire Entities pursuant to the sale and purchase agreement. As of December 31, 2017, the equity method investment balance is reduced to nil after the pickup of loss in the WiFire Entities.

In January 2018, the Company through its subsidiary, 21Vianet Beijing, and a third company jointly set up Beijing Jingliang Interconnected Cloud Technology Inc. (“Jingliang Inter Cloud”) and Jingliang Century Cloud Technology Inc. (“Jingliang Century Cloud”). The Company injected capital of RMB6,000 (US$873) and RMB4,000 (US$582) and the Company held 60% and 40% of equity interest in Jingliang Inter Cloud and Jingliang Century Cloud, respectively. Based on the article of association, the Company cannot exercise control over relevant activities of the investees, but it has the ability to exercise significant influence over operation and financial decisions of Jingliang Inter Cloud and Jingliang Century Cloud.

In March 2018, the Company through its subsidiary, 21Vianet Beijing, acquired 50% equity interest in Guangdong Huaye Cloud Inc. (“Huaye Cloud”) with an amount of RMB23,333 (US$3,394), with the ability to exercise significant influence.

Available-for-sale debt investments

Available-for-sale debt investments consisted of investments in convertible notes with conversion option to preferred shares that are not readily convertible to cash and therefore the bifurcation of embedded derivative is not required as the conversion option did not qualify as derivatives in accordance with ASC Topic 815, Derivatives and Hedging, (“ASC 815”).

Debt Disclosure

12 Months Ended

Dec. 31, 2018

Bank Borrowings

Debt Disclosure

13.

BANK BORROWINGS

Bank borrowings were as follows as of the respective balance sheet dates:


	As of December 31,
	2017		2018
	RMB		RMB		US$
Short-term bank borrowings		50,000		50,000		7,272
Long-term bank borrowings, current portion		70,289		75,284		10,950

		120,289		125,284		18,222
Long-term bank borrowings, non-current portion		187,638		112,000		16,290

Total bank borrowings		307,927		237,284		34,512

The short-term bank borrowings outstanding as of December 31, 2017 and 2018 bore a weighted average interest rate of 4.04% and 4.05% per annum, respectively, and were denominated in RMB. These borrowings were obtained from financial institutions and have terms of one year. The long-term bank borrowings (including current portion) outstanding as of December 31, 2017 and 2018 bore a weighted average interest rate of 5.50% and 5.31% per annum, and were denominated in RMB. These loans were obtained from financial institutions located in the PRC.

As of December 31, 2017 and 2018, unused loan facilities for bank borrowings amounted to RMB140,940 and RMB21,375 (US$3,109), respectively.

Bank borrowings as of December 31, 2017 and 2018 were secured by the following:

December 31, 2017


Short-term bank borrowings		Secured by
(RMB)
	50,000	Secured by restricted cash of RMB50,809.

	50,000


Long-term bank borrowings (including current portion)		Secured by
(RMB)
	158,000	Secured by a subsidiary’s fixed assets and land-use right with net book value of RMB344,932 and RMB16,818, respectively (Note 8/Note 10).
	99,927	Unsecured borrowings.

	257,927


December 31, 2018 Short-term bank borrowings		Secured by
(RMB)
	50,000	Secured by restricted cash of RMB60,796 (US$8,842).

	50,000


Long-term bank borrowings (including current portion)		Secured by
(RMB)
	138,000	Secured by a subsidiary’s fixed assets and land-use right with net book value of RMB286,596 (US$41,683) and RMB16,403 (US$2,386), respectively (Note 8/Note 10).
	49,284	Unsecured borrowings.

	187,284

Bonds Payable

Debt Disclosure

16.

BONDS PAYABLE

On August 17, 2017, the Company issued and sold bonds with an aggregate principal amount of US$200,000 at a coupon rate of 7% per annum, or the original bonds. On September 29, 2017, the Company issued and sold follow-on bonds with an aggregate principal amount of US$100,000 at a coupon rate of 7% per annum, or the Bonds. The Bonds were priced at a slight premium of 100.04%, with an effective yield of 6.98% (together with the original bonds, “2020 Notes”). The 2020 Notes will mature on August 17, 2020. The 2020 Notes were listed and quoted on the Official List of the Singapore Exchange Securities Trading Limited. Interest on the 2020 Notes is payable semi-annually in arrears on August 17 and February 17 in each year, beginning from February 17, 2018.

Net proceeds from 2020 Notes after deducting issuance costs were RMB1,926,419. The proceeds from issuance of 2020 Notes will be used for refinancing outstanding indebtedness, fund future capital needs, and for general corporate purposes.

The 2020 Notes are unsecured and rank senior in right of payment to any of the Company’s indebtedness that is expressly subordinated to the bonds; equal in right of payment to any of the Company’s liabilities that are not so subordinated; but rank lower than any secured indebtedness of the Company and all liabilities (including accounts payable) of the Company’s subsidiaries and Consolidated VIEs.

The following table summarizes the aggregate required repayments of the principal amounts of the Company’s long-term borrowings, including the bonds payable and bank borrowings (Note 13) in the succeeding five years and thereafter:


	RMB		US$
For the years ending December 31,
2019		125,284		18,222
2020		2,091,460		304,190
2021		39,000		5,672
2022		40,500		5,890
2023 thereafter		—		—

Accrued Expenses And Other Payables

12 Months Ended

Dec. 31, 2018

Payables and Accruals [Abstract]

Accrued Expenses And Other Payables

14.

ACCRUED EXPENSES AND OTHER PAYABLES

The components of accrued expenses and other payables were as follows:


	As of December 31,
	2017		2018
	RMB		RMB		US$
Payroll and welfare payables		197,171		224,265		32,618
Value-added tax and other taxes payable		16,951		16,931		2,463
Payables for office supplies and utilities		29,488		21,719		3,159
Payables for the purchase of property and equipment		185,594		207,512		30,181
Payables for the purchase of intangible assets		3,706		4,576		666
Accrued service fees		52,090		41,618		6,053
Interest payables		57,359		54,376		7,909
Liability classified RSU		11,865		4,970		723
Payables for acquisitions		47,755		47,755		6,946
Payables for litigation settlement		9,801		—		—
Others		45,353		35,598		5,176

	657,133		659,320		95,894

Capital Leases

12 Months Ended

Dec. 31, 2018

Leases [Abstract]

Capital Leases

15.

CAPITAL LEASES

Certain property, computer and network equipment and optical fibers were acquired through capital leases entered into by the Company.

Future minimum lease payments under non-cancellable capital lease arrangements as lessee are as follows:


	RMB			US$
2019		305,710			44,464
2020		217,525			31,638
2021		317,382			46,161
2022		96,990			14,106
2023 and thereafter		575,941			83,767

Total minimum lease payments		1,513,548			220,136
Less: amount representing interest		(527,860	)		(76,774	)

Present value of remaining minimum lease payments		985,688			143,362

Capital leases bore weighted average interest rates of 9.93% and 10.37% per annum for the years ended December 31, 2017 and 2018, respectively.

Deferred Government Grants

12 Months Ended

Dec. 31, 2018

Revenue Recognition and Deferred Revenue [Abstract]

Deferred Government Grants

17.

DEFERRED GOVERNMENT GRANTS

During the years ended December 31, 2016, 2017 and 2018, the Company received nil, RMB2,877 and RMB500 (US$73), respectively, in government grants from the relevant PRC government authorities for the use in construction of property and equipment. These grants are initially deferred and subsequently recognized in the consolidated statements of operations when the Company has complied with the conditions or performance obligations attached to the related government grants, if any, and the grants are no longer refundable. Grants that subsidize the construction cost of property and equipment are amortized over the life of the related assets as a reduction of the associated depreciation expense.

Movements of deferred government grants were as follows:


	For the years ended December 31,
	2016			2017			2018
	RMB			RMB			RMB			US$
Balance at beginning of the year		37,620			30,993			22,435			3,263
Additions		—			2,877			500			73
Decrease due to disposal of subsidiaries		—			(3,573	)		—			—
Recognized as a reduction of depreciation expense		(6,627	)		(7,862	)		(7,143	)		(1,039	)

Balance at end of the year		30,993			22,435			15,792			2,297

Treasury Stock

12 Months Ended

Dec. 31, 2018

Equity [Abstract]

Treasury Stock

18.

TREASURY STOCK

For the years ended December 31, 2016, 2017 and 2018, the Company repurchased the number of 815,525, 3,448,482 and nil ADSs pursuant to the share repurchase plans.

For the years ended December 31, 2016, 2017 and 2018, 223,161, nil and nil ADSs were issued to settle the contingent purchase consideration in relation to acquisitions.

Accumulated Other Comprehensive (Loss) Income

12 Months Ended

Dec. 31, 2018

Equity [Abstract]

Accumulated Other Comprehensive (Loss) Income

19.

ACCUMULATED OTHER COMPREHENSIVE (LOSS) INCOME

The changes in accumulated other comprehensive (loss) income by component, net of tax of nil, were as follows:


	Foreign currency translation
	RMB
Balance as of January 1, 2016		(24,236	)
Current year other comprehensive income		142,526

Balance as of December 31, 2016		118,290
Current year other comprehensive loss		(120,963	)

Balance as of December 31, 2017		(2,673	)
Current year other comprehensive income		88,652

Balance as of December 31, 2018		85,979

Balance as of December 31, 2018, in US$		12,505

Mainland China Employee Contribution Plan

12 Months Ended

Dec. 31, 2018

Text Block [Abstract]

Mainland China Employee Contribution Plan

20.

MAINLAND CHINA EMPLOYEE CONTRIBUTION PLAN

As stipulated by the regulations of the PRC, full-time employees of the Company in the PRC participate in a government-mandated multiemployer defined contribution plan organized by municipal and provincial governments. Under the plan, certain pension benefits, medical care, unemployment insurance, employee housing fund and other welfare benefits are provided to employees. The Company is required to make contributions to the plan based on certain percentages of employees’ salaries. The total expenses for the plan were RMB130,630, RMB134,053 and RMB122,362 (US$17,797) for the years ended December 31, 2016, 2017 and 2018, respectively.

Share Based Compensation

12 Months Ended

Dec. 31, 2018

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Share Based Compensation

21.

SHARE-BASED COMPENSATION

(a)

Option granted to employees

In order to provide additional incentives to employees and to promote the success of the Company’s business, the Company adopted a share incentive plan in 2010 (the “2010 Plan”). Under the 2010 Plan, the Company may grant options and RSUs to its employees, directors and consultants to purchase an aggregate of no more than 39,272,595 ordinary shares of the Company. The 2010 Plan was approved by the Board of Directors and shareholders of the Company on July 16, 2010. The 2010 Plan is administered by the Board of Directors or the Compensation Committee of the Board as set forth in the 2010 Plan (the “Plan Administrator”). All share options to be granted under the 2010 Plan have a contractual term of ten years and generally vest over 3 to 4 years in the grantee’s option agreement.

In order to further promote the success and enhance the value, the Company adopted a share incentive plan in 2014 (the “2014 Plan”). Under the 2014 Plan, the Company may issue an aggregate of no more than 20,461,380 shares (“Maximum Number”) and such Maximum Number should be automatically increased by a number that is equal to 15% of the number of new shares issued by the Company from time to time. The maximum aggregate number of ordinary shares to be issued under 2014 Plan was subsequently amended to 39,606,817, as approved by the Board of Directors and shareholders of the Company on October 30, 2015. All share options, restricted shares and restricted share units to be granted under the 2014 Plan have a contractual term of ten years and generally vest over 3 to 4 years in the grantee’s option agreement.

The Company granted 1,059,668, 611,111 and 487,368 RSUs in 2016, 2017 and 2018, respectively, with performance conditions whereby a predetermined number will vest upon the assignment of an annual performance review in accordance with predetermined performance targets for the grantees over a one or four-year period. As it is probable for the Company to estimate the annual performance review ratings for the individual grantees, the Company commenced recognition of the related compensation expenses using the accelerated recognition method.

The Company granted 2,188,226 RSUs in 2018 with performance conditions whereby a predetermined number will vest upon with the achievement of predetermined operation performance targets for the Company. As it is probable for the Company to estimate the operation performance for the Company, the Company commenced recognition of the related compensation expenses using the accelerated recognition method.

The Company granted 547,056 RSUs in 2018 with market conditions whereby a predetermined number will vest upon with the achievement of predetermined share price targets for the Company. The probability to achieve market condition is reflected in the grant date fair value of the award and thus compensation cost is recognized when the requisite service is rendered using the accelerated method.

The compensation expenses related to remaining unvested share options shall be recognized over the remaining requisite service period or the performance review period. As of December 31, 2018, options to purchase 1,479,214 of ordinary shares were outstanding.

The following table summarized the Company’s employee share option activity under the 2010 Plan:


	Number of options			Weighted average exercise price		Weighted average remaining contractual term		Aggregate intrinsic value
				(US$)		(Years)		(US$)
Outstanding, January 1, 2018		1,699,186			0.49		3.5
Exercised		(219,972	)		0.31

Outstanding, December 31, 2018		1,479,214			0.51		2.2		1,370

Vested and expected to vest at December 31, 2018		1,479,214			0.51		2.2		1,370

Exercisable as of December 31, 2018		1,479,214			0.51		2.2		1,370

The aggregate intrinsic value is calculated as the difference between the exercise price of the underlying awards and the fair value of the underlying stock at each reporting date, for those awards that have an exercise price below the estimated fair value of the Company’s shares. As of December 31, 2018, the Company had options outstanding to purchase an aggregate of 1,479,214 shares with an exercise price below the fair value of the Company’s shares, resulting in an aggregate intrinsic value of RMB9,419 (US$1,370).

The aggregate fair value of the outstanding options at the grant date was determined to be RMB14,617 (US$2,126) as of December 31, 2018 and such amount is recognized as share-based compensation expenses using the straight-line method for all employee share options granted with graded vesting based on service conditions and the accelerated method for share options granted with graded vesting based on performance conditions. The weighted average grant date fair value of options granted during the years ended December 31, 2016, 2017 and 2018 was US$2, nil and nil, respectively. The total fair value of share options exercised during the years ended December 31, 2016, 2017 and 2018 was US$2,147, US$404, and US$239, respectively. The aggregate intrinsic value of options exercised during the years ended December 31, 2016, 2017 and 2018 was US$1,906, US$306, and US$248, respectively.

As of December 31, 2018, the Company has recorded all the share-based compensation expenses in relation to outstanding share options.

The following table summarized the Company’s RSUs activity under the 2014 Plan:


	Number of RSUs			Weighted average grant date fair value		Weighted average remaining contractual life		Aggregate intrinsic value
				(US$)		(Years)		(US$)
Unvested, January 1, 2018		1,516,898			11.76		7.9
Granted		3,222,650			6.39
Vested		(852,593	)		11.05
Forfeited		(668,503	)		14.95

Unvested, December 31, 2018		3,218,452			6.66		9		27,807

Share-based compensation expenses for RSUs are measured based on the closing fair market value of the Company’s ADS on the date of grant and the reporting date for liability classified RSUs, respectively. The aggregate fair value of the unvested RSUs as of December 31, 2018 was RMB191,187 (US$27,807), and such amount is recognized as share-based compensation expenses using the straight-line method for the RSUs with graded vesting based on service conditions and the accelerated method for the RSUs with graded vesting based on performance conditions, market conditions and share-settled bonuses. The weighted average grant date fair value of RSUs granted during the years ended December 31, 2016, 2017 and 2018 was US$8.85, US$6.31 and US$6.39, respectively. The total fair value of RSUs vested during the years ended December 31, 2016, 2017 and 2018 was US$14,849, US$18,238 and US$9,422, respectively.

As of December 31, 2018, there was RMB84,307 (US$12,262) of unrecognized share-based compensation expenses related to RSUs which is expected to be recognized over a weighted average vesting period of 3.6 years. Total unrecognized share-based compensation expenses may be adjusted for future changes when actual forfeitures incurred.

(b)

Shares issued to management of Dermot Entities

For the years ended December 31, 2016, 2017 and 2018, the Company recorded share-based compensation expenses of RMB10,871, RMB5,752 and nil within the Company’s consolidated statements of operations, respectively.

Total share-based compensation expenses relating to share options and RSUs granted to employees recognized for the years ended December 31, 2016, 2017 and 2018 were as follows:


	For the years ended December 31,
	2016			2017			2018
	RMB			RMB			RMB		US$
Cost of revenues		(4,110	)		(277	)		2,668		388
Sales and marketing expenses		2,490			(681	)		2,139		311
General and administrative expenses		123,273			47,945			53,346		7,759
Research and development expenses		(2,924	)		142			1,385		201

		118,729			47,129			59,538		8,659

Taxation

12 Months Ended

Dec. 31, 2018

Income Tax Disclosure [Abstract]

Taxation

22.

TAXATION

Enterprise

income tax (“EIT”)

Cayman Islands

The Company is incorporated in the Cayman Islands and conducts its primary business operations through the subsidiaries and VIEs in the PRC and Hong Kong. Under the current laws of the Cayman Islands, the Company is not subject to tax on income or capital gain arising in Cayman Islands. Additionally, upon payments of dividends by the Company to its shareholders, no Cayman Islands withholding tax will be imposed.

British Virgin Islands

Subsidiaries in British Virgin Islands are not subject to tax on income or capital gains under the current laws of the British Virgin Islands. Additionally, upon payments of dividends by the Company to its shareholders, no BVI withholding tax will be imposed.

Hong Kong

Subsidiaries in Hong Kong are subject to Hong Kong profits tax rate of 16.5% for the years ended December 31, 2016, 2017 and 2018. They may be exempted from income tax on their foreign-derived income and there are no withholding taxes in Hong Kong on remittance of dividends.

Taiwan

DYX Taiwan branch is incorporated in Taiwan and is subject to Taiwan profits tax rate of 17% for the years ended December 31, 2016, 2017 and 2018.

The PRC

The Company’s PRC subsidiaries are incorporated in the PRC and subject to the statutory rate of 25% on the taxable income in accordance with the Enterprise Income Tax Law (The “EIT Law”), which was effective since January 1, 2008, except for certain entities eligible for preferential tax rates.

Dividends, interests, rent or royalties payable by the Company’s PRC subsidiaries, to non-PRC resident enterprises, and proceeds from any such non-resident enterprise investor’s disposition of assets (after deducting the net value of such assets) shall be subject to 10% withholding tax, unless the respective non-PRC resident enterprise’s jurisdiction of incorporation has a tax treaty or arrangement with China that provides a reduced withholding tax rate or an exemption from withholding tax.

21Vianet Beijing was qualified for a High and New Technology Enterprise (“HNTE”) since 2008 and is eligible for a 15% preferential tax rate. In October 2014, 21Vianet Beijing obtained a new certificate and renewed the certificate in October 2017, which will expire in October 2020. In accordance with the PRC Income Tax Laws, an enterprise awarded with the HNTE certificate may enjoy a reduced EIT rate of 15%. For the years ended December 31, 2016, 2017 and 2018, 21Vianet Beijing enjoyed a preferential tax rate of 15%.

In April 2011, Xi’an Sub, a subsidiary located in Shaanxi Province, was qualified for a preferential tax rate of 15% and started to apply this rate from then on. The preferential tax rate is awarded to companies that are located in West Regions of China which operate in certain encouraged industries. This qualification will need to be assessed on an annual basis. For the years ended December 31, 2016, 2017 and 2018, the tax rate assessed for Xi’an Sub was 25%, 25% and 15%, respectively.

In 2013, BJ iJoy was qualified as a software enterprise which allows BJ iJoy to utilize a two-year 100% exemption for 2013 and 2014 followed by a three-year half-reduced EIT rate effective for the years from 2015 to 2017. For the years ended December 31, 2013 and 2014, BJ iJoy enjoyed the 100% tax exemption for its taxable income. For the years ended December 31, 2015, 2016 and 2017, BJ iJoy enjoyed the half-reduced EIT rate for its taxable income. For the year ended December 31, 2018, BJ iJoy was subject to the statutory rate of 25% for the taxable income.

In October 2015, SH Blue Cloud, a subsidiary located in Shanghai, was qualified for a HNTE and became eligible for 15% preferential tax rate effective for three consecutive years. The certificate was renewed in October 2018 which will expire in October 2021. Accordingly, for the years ended December 31, 2016, 2017 and 2018, SH Blue Cloud enjoyed a preferential tax rate of 15%.

In November 2016, SZ DYX, a subsidiary located in Guangdong Province, was qualified for a HNTE and became eligible for 15% preferential tax rate effective for three consecutive years, expiring in November 2019 and thereafter for an additional three years if it is able to meet HNTE technical and administrative requirements in those three years. Accordingly, for the years ended December 31, 2016, 2017 and 2018, SZ DYX enjoyed a preferential tax rate of 15%.

The New EIT Law also provides that enterprises established under the laws of foreign countries or regions and whose “place of effective management” is located within the PRC are considered PRC tax resident enterprises and subject to PRC income tax at the rate of 25% on worldwide income. The definition of “place of effective management” refers to an establishment that exercises, in substance, overall management and control over the production and business, personnel, accounting, properties, etc. of an enterprise. As of December 31, 2018, the administrative practice associated with interpreting and applying the concept of “place of effective management” is unclear. If the Company is deemed as a PRC tax resident, it will be subject to 25% PRC EIT under the New EIT Law on its worldwide income, meanwhile the dividend it receives from another PRC tax resident company will be exempted from 25% PRC income tax. The Company will continue to monitor changes in the interpretation or guidance of this law.

Loss before income taxes consisted of:


	For the years ended December 31,
	2016			2017			2018
	RMB			RMB			RMB			US$
Non-PRC		(155,364	)		(286,388	)		(214,063	)		(31,136	)
PRC		(787,718	)		(721,426	)		51,738			7,525

		(943,082	)		(1,007,814	)		(162,325	)		(23,611	)

Income tax benefits (expenses) comprised of:


	For the years ended December 31,
	2016			2017			2018
	RMB			RMB			RMB			US$
Current		(54,772	)		(37,856	)		(44,187	)		(6,426	)
Deferred		65,932			128,026			19,776			2,876

		11,160			90,170			(24,411	)		(3,550	)

The reconciliation of tax computed by applying the statutory income tax rate of 25% for the years ended December 31, 2016, 2017 and 2018 applicable to the PRC operations to income tax benefits (expenses) was as follows:


	For the years ended December 31,
	2016			2017			2018
	RMB			RMB			RMB			US$
Loss before income taxes		(943,082	)		(1,007,814	)		(162,325	)		(23,611	)
Income tax benefits computed at applicable tax rates (25%)		235,770			251,954			40,581			5,902
Non-deductible expenses		(16,610	)		(5,468	)		(2,834	)		(412	)
Research and development expenses		7,766			11,895			25,906			3,768
Effect of tax holidays		1,691			—			—			—
Preferential rate		(11,060	)		(90,076	)		11,701			1,702
Current and deferred tax rate differences		(1,521	)		33,366			37,934			5,517
International rate differences		(51,392	)		59,029			(63,525	)		(9,239	)
Tax exempted income		9,878			—			—			—
Unrecognized tax benefits		(14,525	)		(6,259	)		1,472			214
Deferred tax expense		1,516			2,851			—			—
Change in valuation allowance		(158,724	)		(174,388	)		(79,694	)		(11,591	)
Prior year provision to return true up		8,371			7,266			4,048			589

Income tax benefits (expenses)		11,160			90,170			(24,411	)		(3,550	)

The benefit of the tax holiday per basic and diluted earnings per share was as follows:


	For the years ended December 31,
	2016		2017		2018
	RMB		RMB		RMB		US$
Basic		0.003		—		—		—

Diluted		0.003		—		—		—

Deferred

Tax

The significant components of deferred taxes were as follows:


	As of December 31,
	2017			2018
	RMB			RMB			US$
Deferred tax assets
Non-current
Allowance for doubtful debt		33,978			38,993			5,670
Accrued expenses		7,409			25,894			3,766
Tax losses		135,433			153,171			22,278
Property and equipment		7,642			15,299			2,226
Intangible assets		2,976			2,221			323
Capital lease		22,006			50,980			7,415
Deferred government grants		3,728			2,662			387
Disposal loss on long-term investments		57,697			49,007			7,128
Loss picked up on equity method investments		6,919			5,878			855
Valuation allowance		(104,970	)		(184,664	)		(26,858	)

Total deferred tax assets		172,818			159,441			23,190

Deferred tax liabilities
Non-current
Intangible assets		97,915			89,536			13,022
Property and equipment		49,676			48,496			7,053
Capitalized interest expenses		16,185			15,837			2,303
Gain picked up from equity method investments		27,097			3,851			561

Total deferred tax liabilities		190,873			157,720			22,939

Valuation allowance is considered for each of the entities. Realization of the net deferred tax assets is dependent on factors including future reversals of existing taxable temporary differences and adequate future taxable income, exclusive of reversing deductible temporary differences and tax loss or credit carry forwards. The Company evaluates the potential realization of deferred tax assets on an entity-by-entity basis. As of December 31, 2017 and 2018, valuation allowances were provided against deferred tax assets in entities where it was determined it was more likely than not that the benefits of the deferred tax assets will not be realized in future years.

As of December 31, 2018, the Company has net tax operating losses from its PRC subsidiaries and its Consolidated VIEs, as per filed tax returns, of RMB454,513 (US$66,106), which will expire between 2019 to 2028.

As of December 31, 2018, the Company intends to permanently reinvest the undistributed earnings from other foreign subsidiaries to fund future operations. As of December 31, 2018, the total amount of undistributed earnings from its PRC subsidiaries as well as VIEs was RMB1,123,491 (US$163,405). The amount of unrecognized deferred tax liabilities for temporary differences related to investments in foreign subsidiaries is not determined because such a determination is not practicable.

Unrecognized

Tax Benefits

As of December 31, 2017 and 2018, the Company recorded unrecognized tax benefits of RMB16,511 and RMB6,677 (US$971), respectively.

The unrecognized tax benefits and its related interest are primarily related to non-deductible expenses and accrued expenses. RMB1,896 of the total unrecognized tax benefits, ultimately recognized, will impact the effective tax rate. It is possible that the amount of uncertain tax benefits will change in the next 12 months, however, an estimate of the range of the possible outcomes cannot be made at this time.

A roll-forward of unrecognized tax benefits principal was as follows:


	For the years ended December 31,
	2017			2018
	RMB			RMB			US$
Balance at beginning of year		23,220			11,582			1,685
Reversal based on tax positions related to prior years		(8,880	)		(9,070	)		(1,319	)
Additions based on tax positions related to the current year		4,825			1,997			290
Decrease due to disposal of subsidiaries		(7,583	)		—			—

Balance at end of year		11,582			4,509			656

For the years ended December 31, 2016, 2017 and 2018, the Company recorded (reversed) interest expenses of RMB2,779, RMB674 and RMB(2,761) (US$(402)), respectively. Accumulated interest expenses recorded by the Company was RMB4,929 and RMB2,168 (US$315) as of December 31, 2017 and 2018, respectively. As of December 31, 2018, the tax years ended December 31, 2013 through 2018 for the PRC subsidiaries remain open for statutory examination by the PRC tax authorities.

Related Party Transactions

12 Months Ended

Dec. 31, 2018

Related Party Transactions

23.

RELATED PARTY TRANSACTIONS

Related parties *


Name of related parties		Relationship with the Company
Shanghai Shibei Hi-Tech Co., Ltd. (“SH Shibei”)		Noncontrolling shareholder of a subsidiary
A PRC citizen		Seller of iJoy
Mr. Li ⁽³⁾		Seller of Aipu Group
Dyxnet Internet Center Limited (“DIC”)		A related party of seller of Dermot Entities
Beijing Cheetah Mobile Technology Co., Ltd. (“BJ Cheetah”) ⁽¹⁾		A company controlled by principal shareholder of the Company
Beijing Kingsoft Cloud Network Technology Co., Ltd. (“BJ Kingsoft”) ⁽¹⁾		A company controlled by principal shareholder of the Company
Xiaomi Communication Technology Co., Ltd., and its subsidiary, Beijing Xiaomi Mobile Software Co., Ltd. (collectively, “Xiaomi Group”) ⁽²⁾		A group controlled by principal shareholder of the Company
WNT Technology Limited (“WNT Technology”)		A related party of seller of Dermot Entities
Chengdu Guotao Communication Co., Ltd. (“CD Guotao”) ⁽³⁾		A related party of the controlling shareholder of Aipu Group
Dyxnet Data Centre Services Limited (“DCSS”)		A related party of seller of Dermot entities
Beijing Chengyishidai Network Engineering Technology Co., Ltd. (“CYSD”) ⁽⁴⁾		Equity investee of the Company
WiFire (Beijing) Technology Co., Ltd. (“WiFire BJ”) ⁽⁴⁾		Equity investee of the Company
Beijing Fastweb Network Technology Co., Ltd. (“BJ Fastweb”) ⁽⁴⁾		Equity investee of the Company
Shanghai Fawei Technology Co., Ltd. (“SH Fawei”) ⁽⁴⁾		Equity investee of the Company
Wuhan Fastweb Cloud Computing Co., Ltd. (“WH Fastweb”) ⁽⁴⁾		Equity investee of the Company
Beijing Bozhi Ruihai Network Technology Co., Ltd. (“BZRH”) ⁽⁴⁾		Equity investee of the Company
Unisvnet Technology Co., Ltd. (“Unisvnet”)		A company controlled by controlling shareholder of the Company
Beijing Taiji Data Tech Co., Ltd. (“Taiji”)		Equity investee of the Company
WiFire (Shanghai) Network Technology Co., Ltd. (“SH Guotong”)		Equity investee of the Company
Jingliang Interconnected Cloud Technology Co., Ltd. (“Jingliang Inter Cloud”)		Equity investee of the Company
Beijing Tuspark Harmonious Investment Development Co., Ltd. (“Tuspark Harmonious”)		A company controlled by controlling shareholder of the Company
Ziguang Financial Leasing Co., Ltd. (“Ziguang Financial Leasing”)		A company controlled by controlling shareholder of the Company
Shihua DC Investment Holdings 2 Limited (“Shihua DC Holdings”)		A joint venture under equity method investment of the Company

*	These are the related parties that have engaged in significant transactions with the Company for the years ended December 31, 2016, 2017 and 2018.

(1)	These companies and Kingsoft are ultimately controlled by the same party. Kingsoft made a significant investment in the Company in 2015.

(2)	These companies and Xiaomi are ultimately controlled by the same party. Xiaomi made a significant investment in the Company in 2015.

(3)	These entities ceased to be related parties immediately after the disposal of Aipu Group in 2017.

(4)	These entities were disposed by the Company in September 2017, included in WiFire Entities, and determined by the Company as related parties as of December 31, 2017 and 2018.

Other than disclosed elsewhere, the Company had the following significant related party transactions for the years ended December 31, 2016, 2017 and 2018:


	For the years ended December 31,
	2016		2017		2018
	RMB		RMB		RMB		US$
Services provided to:
- Xiaomi Group		125,147		220,110		374,085		54,408
- WiFire BJ		—		9,726		16,490		2,398
- Taiji		—		—		13,681		1,990
- BJ Kingsoft		19,471		8,046		6,281		914
- BJ Cheetah		9,478		5,128		2,079		302
- Unisvnet		—		—		1,011		147
- Others		2,413		3,314		4,493		653

Services provided by:
- CYSD		—		2,979		18,667		2,715
- BJ Kingsoft		1,045		7,775		13,204		1,920
- Taiji		—		—		7,095		1,032
- DCSS		10,883		6,424		5,238		762
- BZRH		—		—		4,239		617
- WiFire BJ		—		1,616		4,066		591
- Jingliang Inter Cloud		—		—		3,477		506
- Others		9,178		2,632		6,396		963

Sales of equipment and property to:
- BJ Fastweb		—		1,021		—		—

Purchases of equipment and property from:
- WNT Technology		—		2,629		—		—
- DIC		3,079		1,234		—		—

Loan to:
- BJ Fastweb		—		20,000		—		—

Loan from:
- CD Guotao		3,483		—		—		—

Interest income from loan to:
- BJ Fastweb		—		210		700		102

Lease deposit paid to:
- Tuspark Harmonious		—		—		11,472		1,669
- Ziguang Financial Leasing		—		—		2,042		297

Lease payment paid to:
- Ziguang Financial Leasing		—		—		4,897		712

The Company had the following related party balances as of December 31, 2017 and 2018:


	As of December 31,
	2017		2018
	RMB		RMB		US$
Amounts due from related parties:
Current:
- Xiaomi Group		39,016		41,159		5,986
- WiFire BJ		15,321		36,578		5,320
- SH Fawei		10,332		13,742		1,999
- Taiji		—		13,542		1,970
- SH Shibei		9,800		9,800		1,425
- WH Fastweb		4,600		5,131		746
- Unisvnet		—		1,072		156
- BJ Kingsoft		5,663		982		143
- Seller of iJoy		26,137		—		—
- Others		3,387		3,440		500

		114,256		125,446		18,245

Non-current:
- BJ Fastweb		20,210		20,910		3,041
- Tuspark Harmonious		—		11,472		1,669
- Ziguang Financial Leasing		—		2,042		297

		20,210		34,424		5,007

Amounts due to related parties:
Current:
- Tuspark Harmonious		—		13,850		2,014
- Ziguang Financial Leasing		—		8,938		1,300
- SH Guotong		—		8,135		1,183
- CYSD		3,618		7,158		1,041
- Taiji		—		6,724		978
- BZRH		9,358		5,088		740
- BJ Kingsoft		2,070		609		89
- Seller of iJoy		39,068		—		—
- Others		1,561		1,826		266

		55,675		52,328		7,611

Non-current:
- Tuspark Harmonious		—		443,622		64,522
- Shihua DC Holdings		—		48,329		7,029
- Ziguang Financial Leasing		—		12,527		1,822

		—		504,478		73,373

Segment Reporting

12 Months Ended

Dec. 31, 2018

Segment Reporting [Abstract]

Segment Reporting

24.

SEGMENT REPORTING

As of December 31, 2016, the operations of the Company were organized into two segments, consisting of the hosting and related services and managed network services. The Company derived the results of the segments directly from its internal management reporting system. The CODM measures the performance of each segment based on metrics of revenue and earnings from operations and uses these results to evaluate the performance of, and to allocate resources to, each of the segments. After disposal of WiFire Entities and Aipu Group in September 2017 (Note 4), the Company had only one reporting segment as of December 31, 2017 and 2018.

Because substantially all of the Company’s long-lived assets and revenues are located in and derived from the PRC, geographical segments are not presented.


	For the years ended December 31,
	2016			2017			2018
	RMB			RMB			RMB			US$
Hosting and related services
Revenues		2,668,655			2,975,178			3,401,037			494,660
Cost		(1,936,658	)		(2,130,279	)		(2,456,166	)		(357,235	)

Gross profit		731,997			844,899			944,871			137,425
Operating income (expenses)
Operating income		6,783			5,439			5,027			731
Sales and marketing expenses		(144,335	)		(171,761	)		(172,176	)		(25,042	)
Research and development expenses		(87,227	)		(97,597	)		(92,109	)		(13,397	)
General and administrative expenses		(404,181	)		(417,154	)		(462,637	)		(67,288	)
(Allowance) reversal for doubtful debt		(78,330	)		(6,257	)		598			87
Changes in the fair value of contingent purchase consideration payables		19,394			(937	)		13,905			2,022

Operating profit		44,101			156,632			237,479			34,538
Managed network services
Revenues		973,119			417,527			—			—
Cost		(992,980	)		(504,016	)		—			—

Gross loss		(19,861	)		(86,489	)		—			—
Operating expenses
Sales and marketing expenses		(208,591	)		(84,921	)		—			—
Research and development expenses		(62,110	)		(51,546	)		—			—
General and administrative expenses		(235,467	)		(102,796	)		—			—
Allowance for doubtful debt		(39,234	)		(31,170	)		—			—
Changes in the fair value of contingent purchase consideration payables		73,913			—			—			—
Impairment of goodwill		—			(766,440	)		—			—
Impairment of long-lived assets		(392,947	)		(401,808	)		—			—

Operating loss		(884,297	)		(1,525,170	)		—			—

Group consolidated revenue		3,641,774			3,392,705			3,401,037			494,660
Group consolidated operating (loss) profit		(840,196	)		(1,368,538	)		237,479			34,538

Restricted Net Assets

12 Months Ended

Dec. 31, 2018

Receivables [Abstract]

Restricted Net Assets

25.

RESTRICTED NET ASSETS

The Company’s ability to pay dividends is primarily dependent on the Company receiving distributions of funds from its subsidiaries. Relevant PRC statutory laws and regulations permit payments of dividends by the Company’s PRC subsidiaries only out of their retained earnings, if any, as determined in accordance with PRC accounting standards and regulations. The results of operations reflected in the consolidated financial statements prepared in accordance with U.S. GAAP differ from those reflected in the statutory financial statements of the Company’s PRC subsidiaries.

In accordance with the PRC Regulations on Enterprises with Foreign Investment and the articles of association of the Company’s PRC subsidiaries, a foreign-invested enterprise established in the PRC is required to provide certain statutory reserves, namely general reserve fund, the enterprise expansion fund and staff welfare and bonus fund which are appropriated from net profit as reported in the enterprise’s PRC statutory accounts. A foreign-invested enterprise is required to allocate at least 10% of its annual after-tax profit to the general reserve until such reserve has reached 50% of its respective registered capital based on the enterprise’s PRC statutory accounts. Appropriations to the enterprise expansion fund and staff welfare and bonus fund are at the discretion of the board of directors for all foreign-invested enterprises. The aforementioned reserves can only be used for specific purposes and are not distributable as cash dividends. 21Vianet China was established as a foreign-invested enterprise and, therefore, is subject to the above mandated restrictions on distributable profits. As of December 31, 2017, and 2018, the Company’s PRC subsidiaries had appropriated RMB38,736 and RMB42,403 (US$6,167), respectively, in its statutory reserves.

As a result of these PRC laws and regulations subject to the limit discussed above that require annual appropriations of 10% of after-tax income to be set aside, prior to payment of dividends as general reserve fund, the Company’s PRC subsidiaries are restricted in their ability to transfer a portion of their net assets to the Company. Amounts restricted include paid-in capital, additional paid in capital and statutory reserve funds of the Company’s PRC subsidiaries and the equity of the Consolidated VIEs, as determined pursuant to PRC generally accepted accounting principles, totaling an aggregate of RMB5,234,597 (US$761,341) as of December 31, 2018.

Loss Per Share

12 Months Ended

Dec. 31, 2018

Earnings Per Share [Abstract]

Loss Per Share

26.

LOSS PER SHARE

Basic and diluted loss per share for each of the years presented were calculated as follows:


	For the years ended December 31,
	2016			2017			2018
	RMB			RMB			RMB			US$
*Numerator:*
Net loss		(931,922	)		(917,644	)		(186,736	)		(27,161	)
Net loss (profit) attributable to noncontrolling interest and redeemable noncontrolling interest		298,324			144,914			(18,329	)		(2,666	)

Net loss attributable to ordinary shareholders		(633,598	)		(772,730	)		(205,065	)		(29,827	)
Plus increase in accretion of redeemable noncontrolling interests		(210,484	)		(141,896	)		—			—

Adjusted net loss attributable to ordinary shareholders		(844,082	)		(914,626	)		(205,065	)		(29,827	)

*Denominator:*
Weighted average number of shares outstanding—basic		617,169,833			672,836,226			674,732,130			674,732,130
Weighted average number of shares outstanding—diluted		617,169,833			672,836,226			674,732,130			674,732,130
Loss per share—Basic:
Net loss		(1.37	)		(1.36	)		(0.30	)		(0.04	)

		(1.37	)		(1.36	)		(0.30	)		(0.04	)

Loss per share—Diluted:
Net loss		(1.37	)		(1.36	)		(0.30	)		(0.04	)

		(1.37	)		(1.36	)		(0.30	)		(0.04	)

In 2016, 2017 and 2018, the Company issued 4,500,000, 9,000,000 and nil ordinary shares to its share depositary bank which will be used to settle stock option awards upon their exercise, respectively. No consideration was received by the Company for this issuance of ordinary shares. These ordinary shares are legally issued and outstanding but are treated as escrowed shares for accounting purposes and therefore, have been excluded from the computation of loss per share. Any ordinary shares not used in the settlement of stock option awards will be returned to the Company.

Share Capital

12 Months Ended

Dec. 31, 2018

Federal Home Loan Banks [Abstract]

Share Capital

27.

SHARE CAPITAL

Holders of Class A Ordinary Shares and Class B Ordinary Shares are entitled to the same rights except for voting and conversion rights. In respect of matters requiring a shareholder’s vote, each Class A Ordinary Share is entitled to one vote and each Class B Ordinary Share is entitled to 10 votes. Each Class B Ordinary Share is convertible into one Class A Ordinary Share at any time by the holder. Class A Ordinary Shares are not convertible into Class B Ordinary Shares under any circumstances. Upon any transfer of Class B Ordinary Shares by a holder to any person or entity which is not an affiliate of such holder, such Class B Ordinary Shares will be automatically converted into an equal number of Class A Ordinary Shares.

For the years ended December 31, 2016, 2017 and 2018, 3,261,456, 3,119,052 and 3,070,500 Class A ordinary shares were issued to settle the share options exercised and RSUs vested.

Redeemable Noncontrolling Interests

12 Months Ended

Dec. 31, 2018

Noncontrolling Interest [Abstract]

Redeemable Noncontrolling Interests

28.

REDEEMABLE NONCONTROLLING INTERESTS

In May 2014, the Company acquired 50% equity interests plus one share in SC Aipu. The sale and purchase agreement also provided put options that allows the seller of Aipu Group to sell the remaining 50% equity interests in the Aipu Group in three tranches, namely 28% equity interest in 2015, 11% equity interest in 2016 and the remaining equity interests (including those in 2015 and 2016 if these put options are not exercised) in 2017 for a consideration determined using certain financial or operational targets with a floor of RMB700,000 or a ceiling of RMB800,000, in aggregate. A portion of the consideration is to be settled in cash based on certain financial target stipulated in the sale and purchase agreement. The difference will be settled in cash or shares, with the choice to settle in cash or shares residing with the Company for the first tranche and the seller of Aipu Group in the subsequent tranches.

The noncontrolling interests are to be redeemed by the Company at the option of the seller of Aipu Group (“Written Put Option”) in return for cash and shares where the maximum number of shares required to be delivered is outside of the control of the Company, and thus are accounted for as redeemable noncontrolling interests. The Company elects to recognize the changes in redemption value immediately as they occur and adjust the carrying amount of the noncontrolling interests to the redemption value at the end of each reporting period as if it was the redemption date in accordance with ASC 480. As of December 31, 2015 and 2016, as the remaining 50% equity interests are held by a few non-controllingshareholders where the underlying shares of the Aipu Group are not publicly traded, the Written Put Option are embedded features in the Aipu Group’s shares, which does not qualify for bifurcation accounting. The put options are recognized as part of redeemable non-controlling interests. The redeemable noncontrolling interests were initially recorded at the higher of acquisition date fair value and subsequently adjusted to the balance after attribution of Aipu Group’s net income pursuant to ASC 810, Consolidation, and the redemption value pursuant to ASC 480, which is capped within the aforementioned range. Adjustments to the carrying amount of redeemable noncontrolling interests pursuant to ASC 480, if any, are charged to additional paid-in capital.

Upon the disposal of Aipu Group in September 2017, the redeemable noncontrolling interests recognized was reversed due to the deconsolidation of Aipu Group. However, as the Written Put Option outstanding is legally detachable separately exercisable from the 50% minus one share of equity in Aipu Group held by the Company, the Written Put Option qualifies as a freestanding financial instrument as defined under ASC Topic 480 and the Written Put Option is accounted as derivative liability pursuant to ASC 815. However, in December 2017 as part of the transfer of all the remaining 50% equity interest, the Written Put Option was terminated and the gain was recognized as part of the disposal of subsidiaries for the year ended December 31, 2017.


	For the years ended December 31,
	2016			2017			2018
	RMB			RMB			RMB		US$
Balance at beginning of the year		790,229			700,000			—		—
Loss for the year		(300,713	)		(141,896	)		—		—
Increase in accretion of redeemable noncontrolling interests		210,484			141,896			—		—
Reversal due to extinguishment of put option		—			(700,000	)		—		—

Balance at end of the year		700,000			—			—		—

Fair Value Measurements

12 Months Ended

Dec. 31, 2018

Fair Value Disclosures [Abstract]

Fair Value Measurements

29.

FAIR VALUE MEASUREMENTS

The Company applies ASC 820. ASC 820 defines fair value, establishes a framework for measuring fair value and expands disclosures about fair value measurements. ASC 820 requires disclosures to be provided on fair value measurement.

ASC 820 establishes a three-tier fair value hierarchy, which prioritizes the inputs used in measuring fair value as follows:

Level 1 — Observable inputs that reflect quoted prices (unadjusted) for identical assets or liabilities in active markets.

Level 2 — Include other inputs that are directly or indirectly observable in the marketplace.

Level 3 — Unobservable inputs which are supported by little or no market activity.

ASC 820 describes three main approaches to measuring the fair value of assets and liabilities: (1) market approach; (2) income approach; and (3) cost approach. The market approach uses prices and other relevant information generated from market transactions involving identical or comparable assets or liabilities. The income approach uses valuation techniques to convert future amounts to a single present value amount. The measurement is based on the value indicated by current market expectations about those future amounts. The cost approach is based on the amount that would currently be required to replace an asset.

Cash equivalents, time deposits and bonds payable are classified within Level 1 because they are valued by using quoted market prices.

The contingent purchase consideration payable for the acquired businesses, the share-settled bonus, liability classified RSU and available-for-sale debt securities are classified within Level 3. The contingent purchase considerations are based on the achievement of certain financial targets in accordance with the sales and purchase agreements for the various periods, as well as other non-financial measures. The fair value of the share-settled bonus was estimated using the performance bonuses that the Company estimates to be settled in shares and the observable market prices of the underlying ADSs of the Company. The fair value of liability classified RSU was estimated using the share price and exchange rate that the Company estimates to be settled in shares.

The Company measures equity investments elected to use the measurement alternative at fair value on a nonrecurring basis, in the cases of an impairment charge is recognized, fair value of an investment is remeasured in an acquisition/a disposal, and an orderly transaction for identical or similar investments of the same issuer was identified.

Assets and liabilities measured at fair value on a recurring basis were summarized below:


	Fair value measurement using:
	Quoted prices in active markets for identical assets (Level 1)		Significant other observable inputs (Level 2)		Unobservable inputs (Level 3)		Fair value at December 31, 2017
	RMB		RMB		RMB		RMB
Cash equivalents:
- Time deposits		874,786		—		—		874,786
Short-term investments:
- Time deposits		548,890		—		—		548,890
Long-term investments
- Available-for-sale debt securities		—		—		2,537		2,537

Assets		1,423,676		—		2,537		1,426,213

Long-term borrowings:
- Bonds payable		1,980,529		—		—		1,980,529

Other liabilities:
- Liability classified RSU		—		—		11,865		11,865

Amounts due to related parties:
- Contingent purchase consideration payable in relation to the acquisition of subsidiaries		—		—		36,734		36,734

Liabilities		1,980,529		—		48,599		2,029,128


	Fair value measurement using:
	Quoted prices in active markets for identical assets (Level 1)		Significant other observable inputs (Level 2)		Unobservable inputs (Level 3)		Fair value at December 31, 2018
	RMB		RMB		RMB		RMB		US$
Cash equivalents:
- Time deposits		1,194,425		—		—		1,194,425		173,722

Short-term investments:
- Time deposits		245,014		—		—		245,014		35,636

Long-term investments
- Available-for-sale debt securities		—		—		2,537		2,537		369

Assets		1,439,439		—		2,537		1,441,976		209,727

Long-term borrowings:
- Bonds payable		2,030,361		—		—		2,030,361		295,304

Other liabilities:
- Liability classified RSU		—		—		4,970		4,970		723

Liabilities		2,030,361		—		4,970		2,035,331		296,027

The following table presented a reconciliation of all liabilities measured at fair value on a recurring basis using significant unobservable inputs (level 3):


	Contingent purchase consideration payable
	RMB
Fair value at January 1, 2017		65,797
Changes in the fair value		937
Settlement of contingent purchase consideration payable		(30,000	)
Transfers in and/or out of Level 3		—

Fair value at December 31, 2017		36,734

Changes in the fair value		(13,905	)
Settlement of contingent purchase consideration payable		(22,829	)
Transfers in and/or out of Level 3		—

Fair value at December 31, 2018		—

Fair value at December 31, 2018 (US$)		—


	Share-settled bonus
	RMB
Fair value at January 1, 2017		37,526
Changes in the fair value		(810	)
Reclassification to equity		(22,752	)
Bonuses settled in cash during 2017		(13,964	)
Transfers in and/or out of Level 3		—

Fair value at December 31, 2017		—

Transfers in and/or out of Level 3		—

Fair value at December 31, 2018		—

Fair value at December 31, 2018 (US$)		—


	Liability classified RSU
	RMB
Fair value at January 1, 2017		34,612
Increase in liability classified RSU		61,903
Reclassification to equity		(84,650	)
Transfers in and/or out of Level 3		—

Fair value at December 31, 2017		11,865

Reclassification to equity		(587	)
Reversal of share-settled bonus		(6,308	)
Transfers in and/or out of Level 3		—

Fair value at December 31, 2018		4,970

Fair value at December 31, 2018 (US$)		723

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

Commitments and Contingencies

12 Months Ended

Dec. 31, 2018

Commitments and Contingencies Disclosure [Abstract]

Commitments and Contingencies

30.

COMMITMENTS AND CONTINGENCIES

Capital commitments

As of December 31, 2018, the Company has the following commitments to purchase certain computer and network equipment and construction in progress:


	RMB		US$
2019		1,148,922		167,104
2020		281,529		40,947
2021		147,609		21,469
2022		104,645		15,220
2023 and thereafter		708,597		103,062

		2,391,302		347,802

Operating lease commitments

The Company leases facilities in the PRC, Hong Kong and United States under non-cancelable operating leases expiring on different dates. For the years ended December 31, 2016, 2017 and 2018, total rental expenses for all operating leases amounted to RMB93,869, RMB89,780 and RMB137,649 (US$20,020), respectively. As of December 31, 2018, the Company has future minimum lease payments under non-cancelableoperating leases with initial terms in excess of one year in relation to office premises and data center space consisting of the following:


	RMB		US$
2019		171,404		24,930
2020		131,268		19,092
2021		151,428		22,024
2022		96,025		13,966
2023 and thereafter		813,854		118,370

		1,363,979		198,382

Payments under operating leases are expensed on a straight-line basis over the periods of their respective leases. The terms of the leases do not contain material rent escalation clauses or contingent rents.

Bandwidth

and cabinet capacity purchase commitments

As of December 31, 2018, the Company has outstanding purchase commitments in relation to bandwidth and cabinet capacity consisting of the following:


	RMB		US$
2019		480,159		69,836
2020		196,274		28,547
2021		53,537		7,787
2022		51,166		7,442
2023 and thereafter		8,942		1,300

		790,078		114,912

Managed Network Services

As of December 31, 2018, the Company was still in the process of negotiation with the seller of the Managed Network Entities on the quality assessment of the fiber optic network subsequent to the completion of construction. As this is a pending event subsequent to the acquisition which is unrelated to the original acquisition, the Company concluded that the accounting for any settlement should be separated from that of the business combination. Based on the Company’s best estimate, the fair value of the related contingent purchase consideration in shares of RMB47,755, as determined based on the remeasured amount of December 31, 2012, is accrued as a contingent payable pursuant to ASC 450, Contingencies. The Company is negotiating with the seller of the Managed Network Entities to come to an agreement on the quality assessment of the fiber optic network as of December 31, 2018 and the Company’s estimate of the contingent payable remains unchanged.

Income Taxes

As of December 31, 2018, the Company has recognized an accrual of RMB6,677 (US$971) for unrecognized tax benefits and its interest expenses (Note 22). The final outcome of the tax uncertainty is dependent upon various matters including tax examinations, interpretation of tax laws or expiration of statutes of limitation. However, due to the uncertainties associated with the status of examinations, including the protocols of finalizing audits by the relevant tax authorities, there is a high degree of uncertainty regarding the future cash outflows associated with these tax uncertainties. As of December 31, 2018, the Company classified the accrual for unrecognized tax benefits as a non-current liability.

Securities Litigation

In 2014, the Company and certain of its officers and directors were named as defendants in two putative securities class actions filed in U.S. federal district courts in Texas, The complaints in both actions alleged that certain of the Company’s financial statements and other public disclosures contained misstatements or omissions and asset claims under the U.S. securities laws. In 2016, the Company filed a motion to dismiss the complaint and in 2017, the magistrate judge issued a report and recommendation to deny the Company’s motion to dismiss.

On April 9, 2018, the lead plaintiff of the putative class action filed an unopposed motion for preliminary approval of class action settlement, requesting that, among others, the Court preliminarily approve a settlement agreement that the parties reached to settle the case for RMB58,808 (US$9,000). The unopposed motion for preliminary approval is currently pending before the Court.

The Company assessed that the settlement is probable and recorded an estimated loss after deduction of insurance claim of RMB10,007 within accrued expenses and other payables in the consolidated balance sheets as of December 31, 2017. The Company has paid the settlement amount as of December 31, 2018.

Subsequent Events

12 Months Ended

Dec. 31, 2018

Subsequent Events [Abstract]

Subsequent Events

31.

SUBSEQUENT EVENTS

On December 25, 2018, the Company through its subsidiary, 21Vianet Beijing entered into a share purchase agreement to acquire 100% equity interests in Beijing Shuhai Data Technology Co., Ltd (“BJ Shuhai”) with total cash consideration of RMB100,000 (US$14,544) in installment upon achievement of certain conditions. The purpose is to establish a new data center with the acquired property. As of December 31, 2018, the transaction was not yet closed.

Parent Company Only Condensed Financial Information

12 Months Ended

Dec. 31, 2018

Condensed Financial Information Disclosure [Abstract]

Parent Company Only Condensed Financial Information

32.

PARENT COMPANY ONLY CONDENSED FINANCIAL INFORMATION

Condensed balance sheets


				As of December 31,
	Notes			2017			2018
				RMB			RMB			US$
ASSETS
Current assets
Cash and cash equivalents					845,632			590,470			85,880
Restricted cash					71,412			—			—
Short-term investments					548,873			150,990			21,961
Prepaid expenses and other current assets					131,834			98,337			14,303
Amount due from a related party		(b	)		26,137			—			—
Amounts due from subsidiaries		(b	)		4,285,743			5,062,149			736,259

Total current assets					5,909,631			5,901,946			858,403


Non-current assets
Investments in subsidiaries and Consolidated VIEs					1,259,455			1,364,685			198,485

Total non-current assets					1,259,455			1,364,685			198,485

Total assets					7,169,086			7,266,631			1,056,888

LIABILITIES AND SHAREHOLDERS’ EQUITY
Current liabilities:
Accrued expenses and other payables					70,504			56,656			8,241
Accounts payable					6,351			2,725			396
Interest payable					56,809			53,965			7,849
Amount due to a related party		(b	)		39,068			—			—
Amounts due to subsidiaries		(b	)		17,613			21,242			3,090

Total current liabilities					190,345			134,588			19,576


Non-current liabilities
Bonds payable		(d	)		1,929,208			2,037,836			296,391

Total non-current liabilities					1,929,208			2,037,836			296,391

Total liabilities					2,119,553			2,172,424			315,967

Shareholders’ equity:
Class A Ordinary shares (par value of US$0.00001 per share; 1,200,000,000 and 1,200,000,000 shares authorized; 496,636,128 and 499,706,628 shares issued and outstanding as of December 31, 2017 and 2018, respectively)					34			34			5
Class B Ordinary shares (par value of US$0.00001 per share; 300,000,000 and 300,000,000 shares authorized; 174,649,638 and 174,649,638 shares issued and outstanding as of December 31, 2017 and 2018, respectively)					12			12			2
Additional paid-in capital					8,980,407			9,141,494			1,329,574
Accumulated other comprehensive (loss) income					(2,673	)		85,979			12,505
Accumulated deficit					(3,590,564	)		(3,795,629	)		(552,051	)
Treasury stock					(337,683	)		(337,683	)		(49,114	)

Total shareholders’ equity					5,049,533			5,094,207			740,921

Total liabilities and shareholders’ equity					7,169,086			7,266,631			1,056,888

Condensed

statements of operations


	For the years ended December 31,
	2016			2017			2018
	RMB			RMB			RMB			US$
Operating Expenses
General and administrative expenses		(124,450	)		(145,890	)		(65,949	)		(9,592	)
Changes in the fair value of contingent purchase consideration payables		93,307			(937	)		13,905			2,022

Operating loss		(31,143	)		(146,827	)		(52,044	)		(7,570	)
Other loss		(169,915	)		(95,210	)		(262,186	)		(38,134	)
Share of (losses) profit from subsidiaries and Consolidated VIEs		(432,540	)		(530,693	)		109,165			15,877

Loss before income taxes		(633,598	)		(772,730	)		(205,065	)		(29,827	)
Income tax expense		—			—			—			—

Net loss		(633,598	)		(772,730	)		(205,065	)		(29,827	)

Condensed

statements of comprehensive loss


	For the years ended December 31,
	2016			2017			2018
	RMB			RMB			RMB			US$
Net loss		(633,598	)		(772,730	)		(205,065	)		(29,827	)
Other comprehensive income (loss), net of tax of nil:
Foreign currency translation adjustments, net of tax of nil		142,526			(120,963	)		88,652			12,894

Other comprehensive income (loss), net of tax of nil:		142,526			(120,963	)		88,652			12,894

Comprehensive loss		(491,072	)		(893,693	)		(116,413	)		(16,933	)

Comprehensive loss attributable to the Company’s ordinary shareholders		(491,072	)		(893,693	)		(116,413	)		(16,933	)

Condensed

statements of cash flows


	For the years ended December 31,
	2016 (As adjusted)			2017 (As adjusted)			2018
	RMB			RMB			RMB			US$
Net cash used in operating activities		(78,567	)		(18,324	)		(166,068	)		(24,154	)
Net cash used in investing activities		(617,613	)		(1,291,042	)		(203,651	)		(29,620	)
Net cash generated from (used in) financing activities		2,254,577			(130,187	)		43,145			6,275

Net increase (decrease) in cash and cash equivalents and restricted cash		1,558,397			(1,439,553	)		(326,574	)		(47,499	)
Cash and cash equivalents and restricted cash at beginning of the year		798,200			2,356,597			917,044			133,379

Cash and cash equivalents and restricted cash at end of the year		2,356,597			917,044			590,470			85,880

(a)

Basis of presentation

In the Company-only financial statements, the Company’s investment in subsidiaries is stated at cost plus equity in undistributed earnings of subsidiaries since inception.

The Company records its investment in its subsidiaries under the equity method of accounting as prescribed in ASC 323-10, Investment-Equity Method and Joint Ventures, (“ASC 323-10”), and such investments are presented on the balance sheet as “Investments in subsidiaries and Consolidated VIEs” and the share of the subsidiaries’ profit or loss are presented as “Share of (losses) profits of subsidiaries and Consolidated VIEs” on the condensed statements of operations.

The subsidiaries did not pay any dividends to the Company for the years presented.

Certain information and footnote disclosures normally included in financial statements prepared in accordance with U.S. GAAP have been condensed or omitted and as such, these Company-only financial statements should be read in conjunction with the Company’s consolidated financial statements.

(b)

Related party transactions

The Company had the following related party balances as of December 31, 2017 and 2018:


	As of December 31,
	2017		2018
	RMB		RMB		US$
Amounts due from subsidiaries
- 21Vianet HK		4,143,269		4,938,618		718,292
- HongKong Fastweb Holdings Co., Ltd.		61,637		65,976		9,596
- 21V Mobile		50,453		52,579		7,647
- Ventures		25,549		—		—
- WiFire Open Network Group Ltd.		4,170		4,277		622
- WiFire Group Inc.		653		686		100
- Others		12		13		2

		4,285,743		5,062,149		736,259

Amount due from a related party
Current:
- Seller of iJoy		26,137		—		—

Amounts due to subsidiaries
- 21Vianet Beijing		17,595		18,351		2,669
- Others		18		2,891		421

		17,613		21,242		3,090

As of December 31,

2017

2018

RMB

US$

Amount due to a related party

Current:

- Seller of iJoy

39,068

—

(c)

Commitments

Operating

lease commitments

The Company leases a facility in the United States under non-cancelable operating lease expiring on March 1, 2025. For the years ended December 31, 2016, 2017 and 2018, total rental expense for the operating lease amounted to RMB15,824, RMB5,366 and RMB10,848 (US$1,578), respectively.

As of December 31, 2018, the Company has future minimum lease payments under non-cancelable operating leases with initial terms in excess of one year in relation to data center space consisting of the following:


	RMB		US$
2019		7,878		1,146
2020		7,564		1,100
2021		7,564		1,100
2022		7,564		1,100
2023 and thereafter		8,941		1,300

		39,511		5,746

(d)

Bonds payable

On August 17, 2017, the Company issued and sold bonds with an aggregate principal amount of US$200,000 at a coupon rate of 7% per annum or the Original Bonds. On September 29, 2017, the Company issued and sold follow-on bonds with an aggregate principal amount of US$100,000 at a coupon rate of 7% per annum, or the Bonds. The Bonds were priced at a slight premium of 100.04%, with an effective yield of 6.98% (collectively, “2020 Notes”). The 2020 Notes will mature on August 17, 2020. The 2020 Notes were listed and quoted on the Official List of the Singapore Exchange Securities Trading Limited. Interest on the 2020 Notes is payable semi-annually in arrears on August 17 and February 17 in each year, beginning from February 17, 2018.

Net proceeds from the 2020 Notes after deducting issuance costs were RMB1,926,419. The proceeds from issuance of 2020 Notes will be used for refinancing outstanding indebtedness, fund future capital needs, and for general corporate purposes.

Summary of Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2018

Accounting Policies [Abstract]

Basis of presentation

(a)

Basis of presentation

The accompanying consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”).

Principles of Consolidation

(b)

Principles of consolidation

Use of estimates

(c)

Use of estimates

Foreign Currency

(d)

Foreign currency

Convenience Translation

(e)

Convenience translation

Cash and cash equivalents

(f)

Cash and cash equivalents

Restricted cash

(g)

Restricted cash

Short-term investments

(h)

Short-term investments

All highly liquid investments with original maturities of greater than three months but less than twelve months, are classified as short-term investments. Interest income is included in earnings.

Accounts Receivable and Allowance for Doubtful Debt

(i)

Accounts receivable and allowance for doubtful debt

Inventories

(j)

Inventories

Property and equipment

(k)

Property and equipment


Category		Estimated useful life
Property		25-46 years
Leasehold improvements		Over the shorter of lease term or the estimated useful lives of the assets
Optical fibers		10-20 years
Computer and network equipment		1-10 years
Office equipment		1-8 years
Motor vehicles		4-8 years

Intangible assets

(l)

Intangible assets

Intangible assets have weighted average useful lives from the date of purchase/ acquisition as follows:


Purchased software			6.5 years
Radio spectrum license			15 years
Contract backlog*			4.9 years
Customer relationships*			8.8 years
Supplier relationships*			10 years
Licenses*			15 years
Trade Name*			20 years
Platform software*			5 years
Non-compete agreement*			5 years
Internal-use software			4.9 years

Acquired in the acquisitions of subsidiaries.

Land use rights

(m)

Land use rights

Long-term investments

(n)

Long-term investments

The Company’s long-term investments consist of equity investments without readily determinable fair value, equity method investments and available-for-sale debt investments.

Goodwill

(o)

Goodwill

No impairment loss of goodwill in hosting and related services was recognized for the years ended December 31, 2016, 2017 and 2018, respectively.

Impairment of long-lived assets

(p)

Impairment of long-lived assets

The impairment loss reduced the carrying amount of the long-lived assets of a group on a pro-rata basis using the relative carrying amount of those assets.

The Company recorded impairment charges associated with its long-lived assets and acquired intangibles as follows:


	For the years ended December 31,
	2016		2017		2018
	RMB		RMB		RMB		US$
Impairment of equipment		238,144		237,956		—		—
Impairment of intangible assets		154,803		163,852		—		—

Fair value of financial instruments

(q)

Fair value of financial instruments

Revenue recognition

(r)

Revenue recognition

The Company derives revenue primary from the delivery of Hosting services, VPN services and Cloud services.

Cost of revenues

(s)

Cost of revenues

Advertising expenditures

(t)

Advertising expenditures

Research and development expenses

(u)

Research and development expenses

Government grants

(v)

Government grants

Leases

(w)

Leases

Capitalized interest

(x)

Capitalized interest

As a result of total interest expenses capitalized during the period, the interest expenses for the years ended December 31, 2016, 2017 and 2018, were as follows:


	For the years ended December 31,
	2016			2017			2018
	RMB			RMB			RMB			US$
Interest expense and amortization cost of bonds		113,367			63,354			150,098			21,831
Interest expense on bank borrowings		46,377			87,916			19,395			2,820
Interest expense on capital lease		66,687			63,757			79,935			11,626

Total interest expenses		226,431			215,027			249,428			36,277
Less: Total interest expenses capitalized		(27,842	)		(29,714	)		(13,362	)		(1,943	)

Interest expenses, net		198,589			185,313			236,066			34,334

Income taxes

(y)

Income taxes

Share-based compensation

(z)

Share-based compensation

On April 15, 2016 (“the Modification date”), the Company made revisions to the Share-Settled Bonus to remove the agreed premium and six month lock-up period for the employees above a specified level and the option to settle in share for the employees below a specified level. The modified awards remain as liabilities in accordance with ASC 718 as the Company can only settle the Share-Settled Bonus by issuing variable number of shares until the settlement date or in cash. In January, 2017, the Company made revisions to the Share-Settled Bonus to remove the option to settle bonus accrued in 2017. For the Share-Settled Bonus accrued in 2016 which were elected to be settled in shares, the Company issued shares to settle all the Share-Settled Bonus as of December 31, 2017.

The Company adopted ASU No. 2016-09, Improvements to Employee Share-Based Payment Accounting, (“ASU 2016-09”), and elected to account for forfeitures as they occur.

Loss per share

(aa)

Loss per share

Share repurchase program

(bb)

Share repurchase program

For the years ended December 31, 2016, 2017 and 2018, the Company repurchased 815,525, 3,448,482 and nil ADSs for a consideration of RMB42,665, RMB133,126 and nil, respectively.

Comprehensive loss

(cc)

Comprehensive loss

Segment reporting

(dd)

Segment reporting

Employee benefits

(ee)

Employee benefits

Comparatives

(ff)

Comparatives

Certain items reported in the prior year’s consolidated financial statements have been reclassified to conform with the current year’s presentation.

Recent accounting pronouncements

gg)

Recent accounting pronouncements

In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842), (“ASU 2016-02”), which requires a lessee to recognize a lease liability and a right-of-use asset for all leases with lease terms of more than 12 months. This guidance is effective for annual reporting periods beginning after December 15, 2018, including interim periods within those years, and early adoption is permitted. In January 2018, the FASB issued ASU No. 2018-01, Leases: Land Easement Practical Expedient, (“ASU 2018-01”), which provides an optional transition practical expedient for land easements. The effective date of the transition requirements for the amendment is the same as the effective date and transition requirements in ASU 2016-02. Subsequently, the FASB issued ASU No. 2018-10 Codification Improvements to Topic 842, Leases, (“ASU 2018-10”), which clarifies certain aspects of the guidance issued in ASU 2016-02; and ASU No. 2018-11, Leases (Topic 842): Targeted Improvements, (“ASU 2018-11”), which provides an additional transition method and a practical expedient for separating components of a contract for lessors. ASU 2016-02 modifies existing guidance for off balance sheet treatment of lessees’ operating leases by requiring lessees to recognize lease assets and lease liabilities. Under ASU 2016-02, lessor accounting is largely unchanged. ASU 2018-10 clarifies certain provisions and correct unintended applications of the guidance such as the application of implicit rate, lessee reassessment of lease classification, and certain transition adjustments that should be recognized to earnings rather than to stockholders’ equity. ASU 2018-11 provides an alternative transition method and practical expedient for separating contract components for the adoption of Topic 842. ASU 2018-11, ASU 2018-10, and ASU 2016-02 (collectively, “the new lease standards”) are effective for public business entities for annual reporting periods and interim periods within those years beginning after December 15, 2018. These new lease standards become effective for the Company on January 1, 2019. The Company will adopt this standard effective January 1, 2019 using the modified retrospective method, and chose to apply the new standard as of the effective date and will not restate comparable period. Consequently, all of the Company’s operating lease commitments were recognized as lease liabilities, with corresponding right-of-use assets, based on the present value of the remaining minimum rental payments under current leasing standards for existing operating leases. The Company will elect the package of practical expedients permitted under the transition guidance within the new standard, which permits the Company not to reassess under the new standard its prior conclusions about lease identification, lease classification and initial direct costs. The Company’s operating leases mainly related to offices and data center space will be subject to ASU 2016-02 and right-of-use assets and lease liabilities will be recognized on the Company’s consolidated balance sheet. The Company currently believes the most significant change will be related to the recognition of right-of-use assets and lease liabilities on the Company’s balance sheet for operating leases. The Company does not expect any material impact on net assets and the consolidated statement of comprehensive loss as a result of adopting the new standards.

Organization (Tables)

12 Months Ended

Dec. 31, 2018

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Summary of Subsidiaries and Consolidated Variable Interest Entities

The Company through its consolidated subsidiaries and variable interest entities (the “VIEs”) are principally engaged in the provision of hosting and related services after the disposal of subsidiaries which are engaged in managed network services in September 2017 (Note 4).

(a)	As of December 31, 2018, the significant subsidiaries of the Company, VIEs and subsidiaries of VIEs are as follows:


Entity	Date of incorporation/ acquisition	Place of incorporation	Percentage of direct ownership by the Company			Principal activities
			Direct
Subsidiaries:
21ViaNet Group Limited (“21Vianet HK”)	May 25, 2007	Hong Kong		100	%	Investment holding
21ViaNet Data Center Co., Ltd. (“21Vianet China”) ⁽¹⁾	June 12, 2000	PRC		100	%	Provision of technical and consultation services and rental of long-lived assets
21Vianet (Foshan) Technology Co., Ltd. (“FS Technology”) ⁽¹⁾	December 20, 2011	PRC		100	%	Trading of network equipment, provision of technical and internet data center services
21Vianet Anhui Suzhou Technology Co., Ltd. (“SZ Technology”) ⁽¹⁾	November 16, 2011	PRC		100	%	Trading of network equipment
21Vianet Hangzhou Information Technology Co., Ltd. (“HZ Technology”) ⁽¹⁾	March 4, 2013	PRC		100	%	Provision of internet data center services
21Vianet Mobile Limited (“21V Mobile”)	April 30, 2013	Hong Kong		100	%	Investment holding and provision of telecommunication services
Joytone Infotech Co., Ltd. (“SZ Zhuoaiyi”) ⁽¹⁾	April 30, 2013	PRC		100	%	Provision of technical and consultation services
21Vianet Ventures Limited (“Ventures”)	March 6, 2014	Hong Kong		100	%	Investment holding
Abitcool (China) Broadband Inc. (“aBitCool DG”) ⁽¹⁾	June 13, 2014	PRC		100	%	Dormant company
Diyixian.com Limited (“DYX”)	August 10, 2014	Hong Kong		100	%	Provision of virtual private network services
21Vianet Zhuhai Financial Leasing Co., Ltd. (“Zhuhai Financial Leasing”) ⁽¹⁾	April 9, 2015	PRC		100	%	Provision of financial leasing business services
21Vianet DRP Investment Holdings Limited (“DRP investment”)	January 10, 2017	Hong Kong		100	%	Investment holding
Shihua DC Investment Holdings Limited (“Shihua Investment”)	March 14, 2017	Cayman		51	%	Investment holding
21Vianet (Xi’an) Technology Co., Ltd. (“Xi’an Tech”) ⁽¹⁾	July 5, 2012	PRC		51	%	Provision of technical and internet data center services
Foshan Zhuoyi Intelligence Data Co., Ltd. (“FS Zhuoyi”) ⁽¹⁾	July 7, 2016	PRC		51	%	Provision of internet data center services
Dermot Holding Limited (“Dermot BVI”) ⁽³⁾	August 8, 2014	British Virgin Islands		100	%	Investment holding

Variable Interest Entities (the “VIEs”):
Beijing Yiyun Network Technology Co., Ltd. (“21Vianet Technology”)⁽¹⁾^/(2)	October 22, 2002	PRC		—		Provision of internet data center services
Beijing iJoy Information Technology Co., Ltd. (“BJ iJoy”) ^(1)/(2)	April 30, 2013	PRC		—		Provision of internet data center, content delivery network services
WiFire Network Technology (Beijing) Co., Ltd. (“WiFire Network”) ^(1)/(2)	April 1, 2014	PRC		—		Provision of telecommunication services

Held directly by 21Vianet Technology:
Beijing 21Vianet Broad Band Data Center Co., Ltd. (“21Vianet Beijing”) ^(1)/(2)	March 15, 2006	PRC		—		Provision of internet data center services

Held directly by 21Vianet Beijing:
21Vianet (Xi’an) Information Outsourcing Industry Park Services Co., Ltd. (“Xi’an Sub”) ^(1)/(2)	June 23, 2008	PRC		—		Provision of internet data center services
Langfang Xunchi Computer Data Processing Co., Ltd. (“LF Xunchi”) ^(1)/(2)	December 19, 2011	PRC		—		Dormant company
Shanghai Blue Cloud Technology Co., Ltd. (“SH Blue Cloud”) ^(1)/(2)	March 21, 2013	PRC		—		Provision of Office 365 and Windows Azure platform services
Beijing Yichengtaihe Investment Co., Ltd. (“BJ Yichengtaihe”) ^(1)/(2)	September 30, 2014	PRC		—		Provision of internet data center services
Beijing Hongyuan Network Technology Co., Ltd. (“BJ Hongyuan”) ^(1)/(2)/(4)	December 8, 2014	PRC		—		Provision of internet data center services
Guangzhou Lianyun Big Data Co. Ltd.^(1)/(2)	April 14, 2016	PRC		—		Provision of internet data center services

Held directly by DYX and LF Xunchi:
Shenzhen Diyixian Telecommunication Co., Ltd. (“SZ DYX”) ⁽¹⁾	August 10, 2014	PRC		100	%	Provision of virtual private network services

(1)	Collectively, the “PRC Subsidiaries”.

(2)	Collectively, the “Consolidated VIEs”.

(3)	On August 10, 2014, the Company and its subsidiary, LF Xunchi, acquired 100% equity interest Dermot BVI and its subsidiaries (collectively referred to as “Dermot Entities”).

(4)	On August 15, 2018, the Company through its subsidiary, 21Vianet Beijing disposed 49% equity interest of BJ Hongyuan to a third party.

Consolidated VIE before Eliminating Intercompany Balances


	As of December 31,
	2017		2018
	RMB		RMB		US$
ASSETS
Current assets:
Cash and cash equivalents		233,673		548,921		79,837
Restricted cash		149,375		203,103		29,540
Accounts receivable (net of allowance for doubtful debt of RMB70,627 and RMB69,723 (US$10,141) as of December 31, 2017 and 2018, respectively)		342,276		375,515		54,616
Short-term investments		—		94,000		13,672
Prepaid expenses and other current assets		809,546		1,013,563		147,417
Amounts due from related parties		86,824		123,726		17,995

Total current assets		1,621,694		2,358,828		343,077

Non-current assets:
Property and equipment, net		2,331,139		3,103,995		451,457
Intangible assets, net		45,203		47,121		6,853
Land use rights, net		74,162		60,078		8,738
Goodwill		302,956		302,647		44,018
Restricted cash		—		33,729		4,906
Deferred tax assets		169,224		156,412		22,749
Amounts due from related parties		—		13,514		1,966
Other non-current assets		67,517		162,392		23,619
Long-term investments		355,894		219,005		31,853

Total non-current assets		3,346,095		4,098,893		596,159

Total assets		4,967,789		6,457,721		939,236

Current liabilities:
Short-term bank borrowings		50,000		50,000		7,272
Accounts and notes payable		157,970		258,048		37,532
Accrued expenses and other payables		368,190		392,619		57,104
Advance from customers		403,244		670,037		97,453
Deferred revenue		49,699		51,026		7,421
Income tax payable		7,400		8,519		1,239
Amounts due to inter-companies ⁽¹⁾		1,863,780		2,117,097		307,919
Amounts due to related parties		16,053		51,763		7,529
Current portion of capital lease obligations		201,315		219,695		31,953
Current portion of long-term bank borrowings		70,289		75,284		10,950
Deferred government grants		4,574		4,173		607

Total current liabilities		3,192,514		3,898,261		566,978


	As of December 31,
	2017		2018
	RMB		RMB		US$
Non-current liabilities:
Amounts due to inter-companies ⁽¹⁾		1,020,972		1,020,972		148,494
Amounts due to related parties		—		504,478		73,373
Non-current portion of long-term bank borrowings		187,638		112,000		16,290
Non-current portion of capital lease obligations		687,176		852,287		123,960
Unrecognized tax benefits		13,225		4,938		718
Deferred tax liabilities		109,339		84,568		12,300
Deferred government grants		17,861		11,619		1,690

Total non-current liabilities		2,036,211		2,590,862		376,825

Total liabilities		5,228,725		6,489,123		943,803


	For the years ended December 31,
	2016			2017			2018
	RMB			RMB			RMB		US$
Net revenues		2,938,319			2,578,893			2,532,854		368,388
Net (loss) profit		(674,685	)		(567,395	)		52,986		7,706


	For the years ended December 31,
	2016 (As adjusted)			2017 (As adjusted)			2018
	RMB			RMB			RMB			US$
Net cash generated from operating activities		106,803			448,051			693,620			100,883
Net cash (used in) generated from investing activities		(470,955	)		(604,507	)		132,522			19,279
Net cash generated from (used in) financing activities		145,678			230,921			(423,467	)		(61,590	)
Net (decrease) increase in cash and cash equivalents and restricted cash		(218,474	)		74,465			402,705			58,572

(1)

- Definition

Tabular disclosure of the significant judgments and assumptions made in determining whether a variable interest (as defined) held by the entity requires the variable interest entity (VIE) (as defined) to be consolidated and (or) disclose information about its involvement with the VIE, individually or in aggregate (as applicable); the nature of restrictions, if any, on the consolidated VIE's assets and on the settlement of its liabilities reported by an entity in its statement of financial position, including the carrying amounts of such assets and liabilities; the nature of, and changes in, the risks associated with involvement in the VIE; how involvement with the VIE affects the entity's financial position, financial performance, and cash flows; the lack of recourse if creditors (or beneficial interest holders) of the consolidated VIE have no recourse to the general credit of the primary beneficiary (if applicable); the terms of arrangements, giving consideration to both explicit arrangements and implicit variable interests, if any, that could require the entity to provide financial support to the VIE, including events or circumstances that could expose the entity to a loss; the methodology used by the entity for determining whether or not it is the primary beneficiary of the variable interest entity; the significant factors considered and judgments made in determining that the power to direct the activities of a VIE that most significantly impact the VIE's economic performance are shared (as defined); the carrying amounts and classification of assets and liabilities of the VIE included in the statement of financial position; the entity's maximum exposure to loss, if any, as a result of its involvement with the VIE, including how the maximum exposure is determined and significant sources of the entity's exposure to the VIE; a comparison of the carrying amounts of the assets and liabilities and the entity's maximum exposure to loss; information about any liquidity arrangements, guarantees, and (or) other commitments by third parties that may affect the fair value or risk of the entity's variable interest in the VIE; whether or not the entity has provided financial support or other support (explicitly or implicitly) to the VIE that it was not previously contractually required to provide or whether the entity intends to provide that support, including the type and amount of the support and the primary reasons for providing the support; and supplemental information the entity determines necessary to provide.

+ References + Details

Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2018

Accounting Policies [Abstract]

Estimated Useful Lives of Property and Equipment

Property and equipment are depreciated using the straight-line method over the estimated useful lives of the assets, as follows:


Category		Estimated useful life
Property		25-46 years
Leasehold improvements		Over the shorter of lease term or the estimated useful lives of the assets
Optical fibers		10-20 years
Computer and network equipment		1-10 years
Office equipment		1-8 years
Motor vehicles		4-8 years

Weighted Average Useful Lives of Intangible Assets

Intangible assets have weighted average useful lives from the date of purchase/ acquisition as follows:


Purchased software			6.5 years
Radio spectrum license			15 years
Contract backlog*			4.9 years
Customer relationships*			8.8 years
Supplier relationships*			10 years
Licenses*			15 years
Trade Name*			20 years
Platform software*			5 years
Non-compete agreement*			5 years
Internal-use software			4.9 years

Acquired in the acquisitions of subsidiaries.

Summary of Impairment Charges Associated with Long-Lived Assets and Acquired Intangibles

The Company recorded impairment charges associated with its long-lived assets and acquired intangibles as follows:


	For the years ended December 31,
	2016		2017		2018
	RMB		RMB		RMB		US$
Impairment of equipment		238,144		237,956		—		—
Impairment of intangible assets		154,803		163,852		—		—

Interest Expense

As a result of total interest expenses capitalized during the period, the interest expenses for the years ended December 31, 2016, 2017 and 2018, were as follows:


	For the years ended December 31,
	2016			2017			2018
	RMB			RMB			RMB			US$
Interest expense and amortization cost of bonds		113,367			63,354			150,098			21,831
Interest expense on bank borrowings		46,377			87,916			19,395			2,820
Interest expense on capital lease		66,687			63,757			79,935			11,626

Total interest expenses		226,431			215,027			249,428			36,277
Less: Total interest expenses capitalized		(27,842	)		(29,714	)		(13,362	)		(1,943	)

Interest expenses, net		198,589			185,313			236,066			34,334

Accounts and Notes Receivable, Net (Tables)

12 Months Ended

Dec. 31, 2018

Receivables [Abstract]

Accounts and Notes Receivable and Allowance for Doubtful Debt

Accounts and notes receivable and the allowance for doubtful debt consisted of the following:


	As of December 31,
	2017			2018
	RMB			RMB			US$
Accounts receivable		526,747			592,669			86,200
Notes receivable		2,720			2,606			379
Allowance for doubtful debt		(73,656	)		(70,970	)		(10,322	)

		455,811			524,305			76,257

Analysis of Allowance for Doubtful Debt

As of December 31, 2017 and 2018, all accounts and notes receivable were due from third party customers. An analysis of the allowance for doubtful debt was as follows:


	For the years ended December 31,
	2017			2018
	RMB			RMB			US$
Balance at beginning of the year		80,910			73,656			10,712
Additional provision charged to expense		69,553			315			46
Write-off of accounts receivable		(19,766	)		(3,001	)		(436	)
Provision included in disposed subsidiaries		(57,041	)		—			—

Balance at end of the year		73,656			70,970			10,322

Short-Term Investments (Tables)

12 Months Ended

Dec. 31, 2018

Investments Schedule [Abstract]

Short-Term Investments

Short-term investments consisted of the following as of December 31, 2017 and 2018:

As of December 31,

2017

2018

RMB

US$

Time deposits

548,890

245,014

35,636

Prepaid Expenses and Other Current Assets (Tables)

12 Months Ended

Dec. 31, 2018

Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]

Prepaid Expenses and Other Current Assets

Prepaid expenses and other current assets consisted of the following:


	As of December 31,
	2017		2018
	RMB		RMB		US$
Prepaid expenses		380,869		565,710		82,279
Staff advances		6,735		10,730		1,561
Interest receivables		17,644		12,037		1,751
Tax recoverables		376,642		421,654		61,327
Deposits		30,669		39,971		5,814
Prepayment for share repurchase plan		42,710		—		—
Loan to third parties		60,805		58,909		8,567
Other receivables		17,676		48,729		7,086

		933,750		1,157,740		168,385

Property and Equipment, Net (Tables)

12 Months Ended

Dec. 31, 2018

Property, Plant and Equipment [Abstract]

Property and Equipment Including Those Held under Capital Leases

Property and equipment, including those held under capital leases, consisted of the following:


	As of December 31,
	2017			2018
	RMB			RMB			US$
At cost:
Property		467,312			753,319			109,566
Leasehold improvements		789,734			932,896			135,684
Computer and network equipment		2,681,759			3,260,336			474,196
Optical fibers		142,723			142,723			20,758
Office equipment		12,671			24,390			3,547
Motor vehicles		1,891			1,841			268

		4,096,090			5,115,505			744,019
Less: Accumulated depreciation		(1,326,511	)		(1,870,640	)		(272,073	)

		2,769,579			3,244,865			471,946
Construction-in-progress		549,845			786,377			114,374

		3,319,424			4,031,242			586,320

Depreciation Expense

Depreciation expense was RMB480,105, RMB523,500 and RMB566,491 (US$82,393) for the years ended December 31, 2016, 2017 and 2018, respectively, and were included in the following captions:


	For the years ended December 31,
	2016		2017		2018
	RMB		RMB		RMB		US$
Cost of revenues		397,014		458,655		520,791		75,746
Sales and marketing expenses		3,759		3,188		986		144
General and administrative expenses		45,746		41,675		28,727		4,178
Research and development expenses		33,586		19,982		15,987		2,325

		480,105		523,500		566,491		82,393

Carrying Amounts of Property and Equipment Held under Capital Leases

The carrying amounts of the Company’s property and equipment held under capital leases at respective balance sheet dates were as follows:


	As of December 31,
	2017			2018
	RMB			RMB			US$
Property		365,353			365,353			53,138
Computer and network equipment		497,532			719,676			104,673
Optical fibers		142,723			142,723			20,758

		1,005,608			1,227,752			178,569
Less: Accumulated depreciation		(262,601	)		(291,579	)		(42,408	)

		743,007			936,173			136,161
Construction-in-progress		130,192			576,022			83,779

		873,199			1,512,195			219,940

Carrying Amounts of Property and Equipment Pledged to Secure Banking Borrowings

The carrying amounts of property and equipment pledged by the Company to secure banking borrowings (Note 13) granted to the Company at the respective balance sheet dates were as follows:


	As of December 31,
	2017		2018
	RMB		RMB		US$
Property		143,893		140,393		20,419
Computer and network equipment		200,954		146,159		21,258
Office equipment		85		44		6

Intangible Assets, Net (Tables)

12 Months Ended

Dec. 31, 2018

Goodwill and Intangible Assets Disclosure [Abstract]

Summary of Intangible Assets

The following table presented the Company’s intangible assets as of the respective balance sheet dates:


	Purchased software			Radio spectrum license			Network use right			Contract backlog			Customer relationships			Licenses			Supplier relationships			Trade names			Platform software			Non-compete agreements			Internal- use software			Property management relationship			Total
	RMB			RMB						RMB			RMB			RMB			RMB			RMB			RMB			RMB			RMB			RMB			RMB
Intangible assets, net January 1, 2017		73,445			91,568			15,834			18,338			412,775			12,557			88,443			168,385			3,924			8,903			40,006			43,163			977,341
Additions		11,073			—			—			—			—			—			—			—			—			—			9,238			—			20,311
Disposals		(5,973	)		—			(15,086	)		—			(134,706	)		(4,000	)		(7,227	)		(37,270	)		—			(4,297	)		(41,660	)		(30,178	)		(280,397	)
Foreign currency translation difference		(905	)		(7,781	)		—			—			—			—			—			—			—			—			—			—			(8,686	)
Amortization expense		(27,011	)		(6,646	)		(748	)		(6,588	)		(52,992	)		(757	)		(19,304	)		(12,217	)		(3,241	)		(3,347	)		(5,524	)		(5,227	)		(143,602	)
Impairment		—			—			—			—			(87,195	)		(3,532	)		(41,768	)		(22,494	)		—			(1,105	)		—			(7,758	)		(163,852	)

Intangible assets, net December 31, 2017		50,629			77,141			—			11,750			137,882			4,268			20,144			96,404			683			154			2,060			—			401,115

Additions		18,744			—			—			—			—			—			—			—			—			—			6,093			—			24,837
Disposals		(6,772	)		—			—			—			—			—			—			—			—			—			—			—			(6,772	)
Foreign currency translation difference		364			3,884			—			—			—			—			—			—			—			—			—			—			4,248
Amortization expense		(15,711	)		(8,117	)		—			(6,588	)		(24,921	)		(385	)		(3,074	)		(5,813	)		(683	)		(110	)		(2,713	)		—			(68,115	)

Intangible assets, net December 31, 2018		47,254			72,908			—			5,162			112,961			3,883			17,070			90,591			—			44			5,440			—			355,313

Intangible assets, net December 31, 2018 (US$)		6,873			10,604			—			751			16,429			565			2,483			13,176			—			6			791			—			51,678

Annual Estimated Amortization Expenses of Intangible Assets

The annual estimated amortization expenses for the intangible assets for each of the next five years are as follows:


	RMB		US$
2019		56,567		8,227
2020		47,232		6,870
2021		45,005		6,545
2022		41,088		5,976
2023		28,322		4,120

		218,214		31,738

Land Use Rights, Net (Tables)

12 Months Ended

Dec. 31, 2018

Text Block [Abstract]

Land Use Rights

Land use rights held by the Company are amortized over the remaining term of the respective land use rights certificates.


	As of December 31,
	2017			2018
	RMB			RMB			US$
Cost		172,520			159,494			23,197
Accumulated amortization		(8,849	)		(12,001	)		(1,745	)

Land use rights, net		163,671			147,493			21,452

Carrying Value of Land Use Rights Pledged by Company to Secure Banking Borrowings

The carrying amounts of land use rights pledged by the Company to secure banking borrowings (Note 13) granted to the Company at the respective balance sheet dates were as follows:

As of December 31,

2017

2018

RMB

US$

Land use rights

16,818

16,403

2,386

Goodwill (Tables)

12 Months Ended

Dec. 31, 2018

Goodwill and Intangible Assets Disclosure [Abstract]

Goodwill

The changes in the carrying amount of goodwill were as follows:


	For the years ended December 31,
	2016		2017			2018
	RMB		RMB			RMB		US$
Balance at beginning of the year		1,755,970		1,755,970			989,530		143,921
Impairment		—		(766,440	)		—		—

Balance at end of the year		1,755,970		989,530			989,530		143,921

Long-Term Investments (Tables)

12 Months Ended

Dec. 31, 2018

Investments Schedule [Abstract]

Long Term Investments

The Company’s long-term investments consisted of the following:


	As of December 31,
	2017		2018
	RMB		RMB		US$
Equity investments without readily determinable fair values		57,567		51,410		7,477
Equity method investments		450,822		490,376		71,322
Available-for-sale debt investments		2,537		2,537		369

		510,926		544,323		79,168

Equity Method Investments

Equity method investments:


	As of December 31, 2016							Increase (decrease) during the year ended December 31, 2017					As of December 31, 2017
	Cost of investments		Share equity gain (loss)			Investments in equity investee		Cost of investments		Share equity gain (loss)			Cost of investments		Share equity gain (loss)			Investments in equity investee
	RMB		RMB			RMB		RMB		RMB			RMB		RMB			RMB
Yizhuang Fund		101,000		85,148			186,148		—		90,888			101,000		176,036			277,036
Unis Tech		49,000		(285	)		48,175		—		(12,676	)		49,000		(12,961	)		36,039
Shihua DC Holdings		—		—			—		147,176		(9,429	)		147,176		(9,429	)		137,747
WiFire Entities		—		—			—		15,000		(15,000	)		15,000		(15,000	)		—

		150,000		84,863			234,863		162,176		53,783			312,176		138,646			450,822


	As of December 31, 2017							Increase (decrease) during the year ended December 31, 2018								As of December 31, 2018
	Cost of investments		Share equity gain (loss)			Investments in equity investee		Cost of investments			Share equity loss			Disposal gain		Cost of investments		Share equity gain (loss)			Disposal gain		Investments in equity investee		Investments in equity investee
	RMB		RMB			RMB		RMB			RMB			RMB		RMB		RMB			RMB		RMB		US$
Yizhuang Fund		101,000		176,036			277,036		—			(150,355	)		—		101,000		25,681			—		126,681		18,425
Unis Tech		49,000		(12,961	)		36,039		(49,000	)		(3,548	)		16,509		—		(16,509	)		16,509		—		—
Shihua DC Holdings		147,176		(9,429	)		137,747		219,447			(24,229	)		—		366,623		(33,658	)		—		332,965		48,428
Jingliang Inter Cloud		—		—			—		6,000			(34	)		—		6,000		(34	)		—		5,966		868
Jingliang Century Cloud		—		—			—		4,000			—			—		4,000		—			—		4,000		582
Huaye Cloud		—		—			—		23,333			(6,319	)		—		23,333		(6,319	)		—		17,014		2,474
ZJK Energy		—		—			—		5,907			(2,157	)		—		5,907		(2,157	)		—		3,750		545
WiFire Entities		15,000		(15,000	)		—		—			—			—		15,000		(15,000	)		—		—		—

		312,176		138,646			450,822		209,687			(186,642	)		16,509		521,863		(47,996	)		16,509		490,376		71,322

Debt Disclosure (Tables)

12 Months Ended

Dec. 31, 2018

Debt Disclosure [Abstract]

Summary of Bank Borrowings

Bank borrowings were as follows as of the respective balance sheet dates:


	As of December 31,
	2017		2018
	RMB		RMB		US$
Short-term bank borrowings		50,000		50,000		7,272
Long-term bank borrowings, current portion		70,289		75,284		10,950

		120,289		125,284		18,222
Long-term bank borrowings, non-current portion		187,638		112,000		16,290

Total bank borrowings		307,927		237,284		34,512

Secured Short Term Bank Borrowings

Bank borrowings as of December 31, 2017 and 2018 were secured by the following:

December 31, 2017


Short-term bank borrowings		Secured by
(RMB)
	50,000	Secured by restricted cash of RMB50,809.

	50,000


Long-term bank borrowings (including current portion)		Secured by
(RMB)
	158,000	Secured by a subsidiary’s fixed assets and land-use right with net book value of RMB344,932 and RMB16,818, respectively (Note 8/Note 10).
	99,927	Unsecured borrowings.

	257,927


December 31, 2018 Short-term bank borrowings		Secured by
(RMB)
	50,000	Secured by restricted cash of RMB60,796 (US$8,842).

	50,000


Long-term bank borrowings (including current portion)		Secured by
(RMB)
	138,000	Secured by a subsidiary’s fixed assets and land-use right with net book value of RMB286,596 (US$41,683) and RMB16,403 (US$2,386), respectively (Note 8/Note 10).
	49,284	Unsecured borrowings

	187,284

Repayments of Principal Amounts of Long-Term Borrowings, Including Bonds Payable, Bank and Other Borrowings


	RMB		US$
For the years ending December 31,
2019		125,284		18,222
2020		2,091,460		304,190
2021		39,000		5,672
2022		40,500		5,890
2023 thereafter		—		—

Accrued Expenses And Other Payables (Tables)

12 Months Ended

Dec. 31, 2018

Payables and Accruals [Abstract]

Components of Accrued Expenses and Other Payables

The components of accrued expenses and other payables were as follows:


	As of December 31,
	2017		2018
	RMB		RMB		US$
Payroll and welfare payables		197,171		224,265		32,618
Value-added tax and other taxes payable		16,951		16,931		2,463
Payables for office supplies and utilities		29,488		21,719		3,159
Payables for the purchase of property and equipment		185,594		207,512		30,181
Payables for the purchase of intangible assets		3,706		4,576		666
Accrued service fees		52,090		41,618		6,053
Interest payables		57,359		54,376		7,909
Liability classified RSU		11,865		4,970		723
Payables for acquisitions		47,755		47,755		6,946
Payables for litigation settlement		9,801		—		—
Others		45,353		35,598		5,176

	657,133		659,320		95,894

Capital Leases (Tables)

12 Months Ended

Dec. 31, 2018

Leases [Abstract]

Future Minimum Lease Payments Under Non Cancellable Capital Lease Arrangements

Future minimum lease payments under non-cancellable capital lease arrangements as lessee are as follows:


	RMB			US$
2019		305,710			44,464
2020		217,525			31,638
2021		317,382			46,161
2022		96,990			14,106
2023 and thereafter		575,941			83,767

Total minimum lease payments		1,513,548			220,136
Less: amount representing interest		(527,860	)		(76,774	)

Present value of remaining minimum lease payments		985,688			143,362

Deferred Government Grants (Tables)

12 Months Ended

Dec. 31, 2018

Revenue Recognition and Deferred Revenue [Abstract]

Movements of Deferred Government Grants

Movements of deferred government grants were as follows:


	For the years ended December 31,
	2016			2017			2018
	RMB			RMB			RMB			US$
Balance at beginning of the year		37,620			30,993			22,435			3,263
Additions		—			2,877			500			73
Decrease due to disposal of subsidiaries		—			(3,573	)		—			—
Recognized as a reduction of depreciation expense		(6,627	)		(7,862	)		(7,143	)		(1,039	)

Balance at end of the year		30,993			22,435			15,792			2,297

Accumulated Other Comprehensive (Loss) Income (Tables)

12 Months Ended

Dec. 31, 2018

Equity [Abstract]

Changes in Accumulated Other Comprehensive (Loss) Income by Component, Net of Tax of Nil

The changes in accumulated other comprehensive (loss) income by component, net of tax of nil, were as follows:


	Foreign currency translation
	RMB
Balance as of January 1, 2016		(24,236	)
Current year other comprehensive income		142,526

Balance as of December 31, 2016		118,290
Current year other comprehensive loss		(120,963	)

Balance as of December 31, 2017		(2,673	)
Current year other comprehensive income		88,652

Balance as of December 31, 2018		85,979

Balance as of December 31, 2018, in US$		12,505

Share Based Compensation (Tables)

12 Months Ended

Dec. 31, 2018

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Summary of Employee Share Option Activity Under Twenty Ten Plan

The following table summarized the Company’s employee share option activity under the 2010 Plan:


	Number of options			Weighted average exercise price		Weighted average remaining contractual term		Aggregate intrinsic value
				(US$)		(Years)		(US$)
Outstanding, January 1, 2018		1,699,186			0.49		3.5
Exercised		(219,972	)		0.31

Outstanding, December 31, 2018		1,479,214			0.51		2.2		1,370

Vested and expected to vest at December 31, 2018		1,479,214			0.51		2.2		1,370

Exercisable as of December 31, 2018		1,479,214			0.51		2.2		1,370

Restricted Stock Units Activity

The following table summarized the Company’s RSUs activity under the 2014 Plan:


	Number of RSUs			Weighted average grant date fair value		Weighted average remaining contractual life		Aggregate intrinsic value
				(US$)		(Years)		(US$)
Unvested, January 1, 2018		1,516,898			11.76		7.9
Granted		3,222,650			6.39
Vested		(852,593	)		11.05
Forfeited		(668,503	)		14.95

Unvested, December 31, 2018		3,218,452			6.66		9		27,807

Total Compensation Expense Recognized Relating to Options Granted to Employees

Total share-based compensation expenses relating to share options and RSUs granted to employees recognized for the years ended December 31, 2016, 2017 and 2018 were as follows:


	For the years ended December 31,
	2016			2017			2018
	RMB			RMB			RMB		US$
Cost of revenues		(4,110	)		(277	)		2,668		388
Sales and marketing expenses		2,490			(681	)		2,139		311
General and administrative expenses		123,273			47,945			53,346		7,759
Research and development expenses		(2,924	)		142			1,385		201

		118,729			47,129			59,538		8,659

Taxation (Tables)

12 Months Ended

Dec. 31, 2018

Income Tax Disclosure [Abstract]

Profit or Loss Before Income Taxes

Loss before income taxes consisted of:


	For the years ended December 31,
	2016			2017			2018
	RMB			RMB			RMB			US$
Non-PRC		(155,364	)		(286,388	)		(214,063	)		(31,136	)
PRC		(787,718	)		(721,426	)		51,738			7,525

		(943,082	)		(1,007,814	)		(162,325	)		(23,611	)

Income Tax (Expense) Benefits

Income tax benefits (expenses) comprised of:


	For the years ended December 31,
	2016			2017			2018
	RMB			RMB			RMB			US$
Current		(54,772	)		(37,856	)		(44,187	)		(6,426	)
Deferred		65,932			128,026			19,776			2,876

		11,160			90,170			(24,411	)		(3,550	)

Reconciliation Tax Computed Applying Statutory Income Tax Rate


	For the years ended December 31,
	2016			2017			2018
	RMB			RMB			RMB			US$
Loss before income taxes		(943,082	)		(1,007,814	)		(162,325	)		(23,611	)
Income tax benefits computed at applicable tax rates (25%)		235,770			251,954			40,581			5,902
Non-deductible expenses		(16,610	)		(5,468	)		(2,834	)		(412	)
Research and development expenses		7,766			11,895			25,906			3,768
Effect of tax holidays		1,691			—			—			—
Preferential rate		(11,060	)		(90,076	)		11,701			1,702
Current and deferred tax rate differences		(1,521	)		33,366			37,934			5,517
International rate differences		(51,392	)		59,029			(63,525	)		(9,239	)
Tax exempted income		9,878			—			—			—
Unrecognized tax benefits		(14,525	)		(6,259	)		1,472			214
Deferred tax expense		1,516			2,851			—			—
Change in valuation allowance		(158,724	)		(174,388	)		(79,694	)		(11,591	)
Prior year provision to return true up		8,371			7,266			4,048			589

Income tax benefits (expenses)		11,160			90,170			(24,411	)		(3,550	)

Tax Holiday Benefit Per Basic and Diluted Earnings Per Share

The benefit of the tax holiday per basic and diluted earnings per share was as follows:


	For the years ended December 31,
	2016		2017		2018
	RMB		RMB		RMB		US$
Basic		0.003		—		—		—

Diluted		0.003		—		—		—

Significant Components of Deferred Taxes

The significant components of deferred taxes were as follows:


	As of December 31,
	2017			2018
	RMB			RMB			US$
Deferred tax assets
Non-current
Allowance for doubtful debt		33,978			38,993			5,670
Accrued expenses		7,409			25,894			3,766
Tax losses		135,433			153,171			22,278
Property and equipment		7,642			15,299			2,226
Intangible assets		2,976			2,221			323
Capital lease		22,006			50,980			7,415
Deferred government grants		3,728			2,662			387
Disposal loss on long-term investments		57,697			49,007			7,128
Loss picked up on equity method investments		6,919			5,878			855
Valuation allowance		(104,970	)		(184,664	)		(26,858	)

Total deferred tax assets		172,818			159,441			23,190

Deferred tax liabilities
Non-current
Intangible assets		97,915			89,536			13,022
Property and equipment		49,676			48,496			7,053
Capitalized interest expenses		16,185			15,837			2,303
Gain picked up from equity method investments		27,097			3,851			561

Total deferred tax liabilities		190,873			157,720			22,939

Unrecognized Tax Benefits

A roll-forward of unrecognized tax benefits principal was as follows:


	For the years ended December 31,
	2017			2018
	RMB			RMB			US$
Balance at beginning of year		23,220			11,582			1,685
Reversal based on tax positions related to prior years		(8,880	)		(9,070	)		(1,319	)
Additions based on tax positions related to the current year		4,825			1,997			290
Decrease due to disposal of subsidiaries		(7,583	)		—			—

Balance at end of year		11,582			4,509			656

Related Party Transactions (Tables)

12 Months Ended

Dec. 31, 2018

Related Party Transactions

Other than disclosed elsewhere, the Company had the following significant related party transactions for the years ended December 31, 2016, 2017 and 2018:


	For the years ended December 31,
	2016		2017		2018
	RMB		RMB		RMB		US$
Services provided to:
- Xiaomi Group		125,147		220,110		374,085		54,408
- WiFire BJ		—		9,726		16,490		2,398
- Taiji		—		—		13,681		1,990
- BJ Kingsoft		19,471		8,046		6,281		914
- BJ Cheetah		9,478		5,128		2,079		302
- Unisvnet		—		—		1,011		147
- Others		2,413		3,314		4,493		653

Services provided by:
- CYSD		—		2,979		18,667		2,715
- BJ Kingsoft		1,045		7,775		13,204		1,920
- Taiji		—		—		7,095		1,032
- DCSS		10,883		6,424		5,238		762
- BZRH		—		—		4,239		617
- WiFire BJ		—		1,616		4,066		591
- Jingliang Inter Cloud		—		—		3,477		506
- Others		9,178		2,632		6,396		963

Sales of equipment and property to:
- BJ Fastweb		—		1,021		—		—

Purchases of equipment and property from:
- WNT Technology		—		2,629		—		—
- DIC		3,079		1,234		—		—

Loan to:
- BJ Fastweb		—		20,000		—		—

Loan from:
- CD Guotao		3,483		—		—		—

Interest income from loan to:
- BJ Fastweb		—		210		700		102

Lease deposit paid to:
- Tuspark Harmonious		—		—		11,472		1,669
- Ziguang Financial Leasing		—		—		2,042		297

Lease payment paid to:
- Ziguang Financial Leasing		—		—		4,897		712

Related Party Balances

c)	The Company had the following related party balances as of December 31, 2017 and 2018:


	As of December 31,
	2017		2018
	RMB		RMB		US$
Amounts due from related parties:
Current:
- Xiaomi Group		39,016		41,159		5,986
- WiFire BJ		15,321		36,578		5,320
- SH Fawei		10,332		13,742		1,999
- Taiji		—		13,542		1,970
- SH Shibei		9,800		9,800		1,425
- WH Fastweb		4,600		5,131		746
- Unisvnet		—		1,072		156
- BJ Kingsoft		5,663		982		143
- Seller of iJoy		26,137		—		—
- Others		3,387		3,440		500

		114,256		125,446		18,245

Non-current:
- BJ Fastweb		20,210		20,910		3,041
- Tuspark Harmonious		—		11,472		1,669
- Ziguang Financial Leasing		—		2,042		297

		20,210		34,424		5,007

Amounts due to related parties:
Current:
- Tuspark Harmonious		—		13,850		2,014
- Ziguang Financial Leasing		—		8,938		1,300
- SH Guotong		—		8,135		1,183
- CYSD		3,618		7,158		1,041
- Taiji		—		6,724		978
- BZRH		9,358		5,088		740
- BJ Kingsoft		2,070		609		89
- Seller of iJoy		39,068		—		—
- Others		1,561		1,826		266

		55,675		52,328		7,611

Non-current:
- Tuspark Harmonious		—		443,622		64,522
- Shihua DC Holdings		—		48,329		7,029
- Ziguang Financial Leasing		—		12,527		1,822

		—		504,478		73,373

Parent Company

Related Party Transactions

The Company had the following related party balances as of December 31, 2017 and 2018:


	As of December 31,
	2017		2018
	RMB		RMB		US$
Amounts due from subsidiaries
- 21Vianet HK		4,143,269		4,938,618		718,292
- HongKong Fastweb Holdings Co., Ltd.		61,637		65,976		9,596
- 21V Mobile		50,453		52,579		7,647
- Ventures		25,549		—		—
- WiFire Open Network Group Ltd.		4,170		4,277		622
- WiFire Group Inc.		653		686		100
- Others		12		13		2

		4,285,743		5,062,149		736,259

Amount due from a related party
Current:
- Seller of iJoy		26,137		—		—

Amounts due to subsidiaries
- 21Vianet Beijing		17,595		18,351		2,669
- Others		18		2,891		421

		17,613		21,242		3,090

As of December 31,

2017

2018

RMB

US$

Amount due to a related party

Current:

- Seller of iJoy

39,068

—

Segment Reporting (Tables)

12 Months Ended

Dec. 31, 2018

Segment Reporting [Abstract]

Summary of Segment Results


	For the years ended December 31,
	2016			2017			2018
	RMB			RMB			RMB			US$
Hosting and related services
Revenues		2,668,655			2,975,178			3,401,037			494,660
Cost		(1,936,658	)		(2,130,279	)		(2,456,166	)		(357,235	)

Gross profit		731,997			844,899			944,871			137,425
Operating income (expenses)
Operating income		6,783			5,439			5,027			731
Sales and marketing expenses		(144,335	)		(171,761	)		(172,176	)		(25,042	)
Research and development expenses		(87,227	)		(97,597	)		(92,109	)		(13,397	)
General and administrative expenses		(404,181	)		(417,154	)		(462,637	)		(67,288	)
(Allowance) reversal for doubtful debt		(78,330	)		(6,257	)		598			87
Changes in the fair value of contingent purchase consideration payables		19,394			(937	)		13,905			2,022

Operating profit		44,101			156,632			237,479			34,538
Managed network services
Revenues		973,119			417,527			—			—
Cost		(992,980	)		(504,016	)		—			—

Gross loss		(19,861	)		(86,489	)		—			—
Operating expenses
Sales and marketing expenses		(208,591	)		(84,921	)		—			—
Research and development expenses		(62,110	)		(51,546	)		—			—
General and administrative expenses		(235,467	)		(102,796	)		—			—
Allowance for doubtful debt		(39,234	)		(31,170	)		—			—
Changes in the fair value of contingent purchase consideration payables		73,913			—			—			—
Impairment of goodwill		—			(766,440	)		—			—
Impairment of long-lived assets		(392,947	)		(401,808	)		—			—

Operating loss		(884,297	)		(1,525,170	)		—			—

Group consolidated revenue		3,641,774			3,392,705			3,401,037			494,660
Group consolidated operating (loss) profit		(840,196	)		(1,368,538	)		237,479			34,538

Loss Per Share (Tables)

12 Months Ended

Dec. 31, 2018

Earnings Per Share [Abstract]

Basic and Diluted Loss Per Share

Basic and diluted loss per share for each of the years presented were calculated as follows:


	For the years ended December 31,
	2016			2017			2018
	RMB			RMB			RMB			US$
*Numerator:*
Net loss		(931,922	)		(917,644	)		(186,736	)		(27,161	)
Net loss (profit) attributable to noncontrolling interest and redeemable noncontrolling interest		298,324			144,914			(18,329	)		(2,666	)

Net loss attributable to ordinary shareholders		(633,598	)		(772,730	)		(205,065	)		(29,827	)
Plus increase in accretion of redeemable noncontrolling interests		(210,484	)		(141,896	)		—			—

Adjusted net loss attributable to ordinary shareholders		(844,082	)		(914,626	)		(205,065	)		(29,827	)

*Denominator:*
Weighted average number of shares outstanding—basic		617,169,833			672,836,226			674,732,130			674,732,130
Weighted average number of shares outstanding—diluted		617,169,833			672,836,226			674,732,130			674,732,130
Loss per share—Basic:
Net loss		(1.37	)		(1.36	)		(0.30	)		(0.04	)

		(1.37	)		(1.36	)		(0.30	)		(0.04	)

Loss per share—Diluted:
Net loss		(1.37	)		(1.36	)		(0.30	)		(0.04	)

		(1.37	)		(1.36	)		(0.30	)		(0.04	)

Redeemable Noncontrolling Interests (Tables)

12 Months Ended

Dec. 31, 2018

Noncontrolling Interest [Abstract]

Redeemable Non Controlling Interests

	For the years ended December 31,
		2016			2017			2018
		RMB			RMB			RMB		US$
Balance at beginning of the year			790,229			700,000			—		—
Loss for the year			(300,713	)		(141,896	)		—		—
Increase in accretion of redeemable noncontrolling interests			210,484			141,896			—		—
Reversal due to extinguishment of put option			—			(700,000	)		—		—

Balance at end of the year			700,000			—			—		—

Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2018

Fair Value Disclosures [Abstract]

Assets and Liabilities Measured at Fair Value on Recurring Basis

Assets and liabilities measured at fair value on a recurring basis were summarized below:


	Fair value measurement using:
	Quoted prices in active markets for identical assets (Level 1)		Significant other observable inputs (Level 2)		Unobservable inputs (Level 3)		Fair value at December 31, 2017
	RMB		RMB		RMB		RMB
Cash equivalents:
- Time deposits		874,786		—		—		874,786
Short-term investments:
- Time deposits		548,890		—		—		548,890
Long-term investments
- Available-for-sale debt securities		—		—		2,537		2,537

Assets		1,423,676		—		2,537		1,426,213

Long-term borrowings:
- Bonds payable		1,980,529		—		—		1,980,529

Other liabilities:
- Liability classified RSU		—		—		11,865		11,865

Amounts due to related parties:
- Contingent purchase consideration payable in relation to the acquisition of subsidiaries		—		—		36,734		36,734

Liabilities		1,980,529		—		48,599		2,029,128


	Fair value measurement using:
	Quoted prices in active markets for identical assets (Level 1)		Significant other observable inputs (Level 2)		Unobservable inputs (Level 3)		Fair value at December 31, 2018
	RMB		RMB		RMB		RMB		US$
Cash equivalents:
- Time deposits		1,194,425		—		—		1,194,425		173,722

Short-term investments:
- Time deposits		245,014		—		—		245,014		35,636

Long-term investments
- Available-for-sale debt securities		—		—		2,537		2,537		369

Assets		1,439,439		—		2,537		1,441,976		209,727

Long-term borrowings:
- Bonds payable		2,030,361		—		—		2,030,361		295,304

Other liabilities:
- Liability classified RSU		—		—		4,970		4,970		723

Liabilities		2,030,361		—		4,970		2,035,331		296,027

Reconciliation of Liabilities Measured at Fair Value on Recurring Basis Using Significant Unobservable Inputs Level Three

The following table presented a reconciliation of all liabilities measured at fair value on a recurring basis using significant unobservable inputs (level 3):


	Contingent purchase consideration payable
	RMB
Fair value at January 1, 2017		65,797
Changes in the fair value		937
Settlement of contingent purchase consideration payable		(30,000	)
Transfers in and/or out of Level 3		—

Fair value at December 31, 2017		36,734

Changes in the fair value		(13,905	)
Settlement of contingent purchase consideration payable		(22,829	)
Transfers in and/or out of Level 3		—

Fair value at December 31, 2018		—

Fair value at December 31, 2018 (US$)		—


	Share-settled bonus
	RMB
Fair value at January 1, 2017		37,526
Changes in the fair value		(810	)
Reclassification to equity		(22,752	)
Bonuses settled in cash during 2017		(13,964	)
Transfers in and/or out of Level 3		—

Fair value at December 31, 2017		—

Transfers in and/or out of Level 3		—

Fair value at December 31, 2018		—

Fair value at December 31, 2018 (US$)		—


	Liability classified RSU
	RMB
Fair value at January 1, 2017		34,612
Increase in liability classified RSU		61,903
Reclassification to equity		(84,650	)
Transfers in and/or out of Level 3		—

Fair value at December 31, 2017		11,865

Reclassification to equity		(587	)
Reversal of share-settled bonus		(6,308	)
Transfers in and/or out of Level 3		—

Fair value at December 31, 2018		4,970

Fair value at December 31, 2018 (US$)		723

- Definition

Tabular disclosure of financial instruments measured at fair value, including those classified in shareholders' equity measured on a recurring or nonrecurring basis. Disclosures include, but are not limited to, fair value measurements recorded and the reasons for the measurements, level within the fair value hierarchy in which the fair value measurements are categorized and transfers between levels 1 and 2. Nonrecurring fair value measurements are those that are required or permitted in the statement of financial position in particular circumstances.

+ References + Details

Commitments and Contingencies (Tables)

12 Months Ended

Dec. 31, 2018

Future Minimum Lease Payments Under Non Cancelable Operating Leases

As of December 31, 2018, the Company has future minimum lease payments under non-cancelable operating leases with initial terms in excess of one year in relation to office premises and data center space consisting of the following:


	RMB		US$
2019		171,404		24,930
2020		131,268		19,092
2021		151,428		22,024
2022		96,025		13,966
2023 and thereafter		813,854		118,370

		1,363,979		198,382

Computer and Network Equipment and Construction in Progress

Purchase Commitments

As of December 31, 2018, the Company has the following commitments to purchase certain computer and network equipment and construction in progress:


	RMB		US$
2019		1,148,922		167,104
2020		281,529		40,947
2021		147,609		21,469
2022		104,645		15,220
2023 and thereafter		708,597		103,062

		2,391,302		347,802

Bandwidth and Cabinet Capacity

Purchase Commitments

As of December 31, 2018, the Company has outstanding purchase commitments in relation to bandwidth and cabinet capacity consisting of the following:


	RMB		US$
2019		480,159		69,836
2020		196,274		28,547
2021		53,537		7,787
2022		51,166		7,442
2023 and thereafter		8,942		1,300

		790,078		114,912

Parent Company

Future Minimum Lease Payments Under Non Cancelable Operating Leases


	RMB		US$
2019		7,878		1,146
2020		7,564		1,100
2021		7,564		1,100
2022		7,564		1,100
2023 and thereafter		8,941		1,300

		39,511		5,746

Parent Company Only Condensed Financial Information (Tables) - Parent Company

12 Months Ended

Dec. 31, 2018

Condensed Balance Sheets

Condensed balance sheets


				As of December 31,
	Notes			2017			2018
				RMB			RMB			US$
ASSETS
Current assets
Cash and cash equivalents					845,632			590,470			85,880
Restricted cash					71,412			—			—
Short-term investments					548,873			150,990			21,961
Prepaid expenses and other current assets					131,834			98,337			14,303
Amount due from a related party		(b	)		26,137			—			—
Amounts due from subsidiaries		(b	)		4,285,743			5,062,149			736,259

Total current assets					5,909,631			5,901,946			858,403


Non-current assets
Investments in subsidiaries and Consolidated VIEs					1,259,455			1,364,685			198,485

Total non-current assets					1,259,455			1,364,685			198,485

Total assets					7,169,086			7,266,631			1,056,888

LIABILITIES AND SHAREHOLDERS’ EQUITY
Current liabilities:
Accrued expenses and other payables					70,504			56,656			8,241
Accounts payable					6,351			2,725			396
Interest payable					56,809			53,965			7,849
Amount due to a related party		(b	)		39,068			—			—
Amounts due to subsidiaries		(b	)		17,613			21,242			3,090

Total current liabilities					190,345			134,588			19,576


Non-current liabilities
Bonds payable		(d	)		1,929,208			2,037,836			296,391

Total non-current liabilities					1,929,208			2,037,836			296,391

Total liabilities					2,119,553			2,172,424			315,967

Shareholders’ equity:
Class A Ordinary shares (par value of US$0.00001 per share; 1,200,000,000 and 1,200,000,000 shares authorized; 496,636,128 and 499,706,628 shares issued and outstanding as of December 31, 2017 and 2018, respectively)					34			34			5
Class B Ordinary shares (par value of US$0.00001 per share; 300,000,000 and 300,000,000 shares authorized; 174,649,638 and 174,649,638 shares issued and outstanding as of December 31, 2017 and 2018, respectively)					12			12			2
Additional paid-in capital					8,980,407			9,141,494			1,329,574
Accumulated other comprehensive (loss) income					(2,673	)		85,979			12,505
Accumulated deficit					(3,590,564	)		(3,795,629	)		(552,051	)
Treasury stock					(337,683	)		(337,683	)		(49,114	)

Total shareholders’ equity					5,049,533			5,094,207			740,921

Total liabilities and shareholders’ equity					7,169,086			7,266,631			1,056,888

Condensed Statements of Operations

Condensed

statements of operations


	For the years ended December 31,
	2016			2017			2018
	RMB			RMB			RMB			US$
Operating Expenses
General and administrative expenses		(124,450	)		(145,890	)		(65,949	)		(9,592	)
Changes in the fair value of contingent purchase consideration payables		93,307			(937	)		13,905			2,022

Operating loss		(31,143	)		(146,827	)		(52,044	)		(7,570	)
Other loss		(169,915	)		(95,210	)		(262,186	)		(38,134	)
Share of (losses) profit from subsidiaries and Consolidated VIEs		(432,540	)		(530,693	)		109,165			15,877

Loss before income taxes		(633,598	)		(772,730	)		(205,065	)		(29,827	)
Income tax expense		—			—			—			—

Net loss		(633,598	)		(772,730	)		(205,065	)		(29,827	)

Condensed Statements of Comprehensive Loss

Condensed

statements of comprehensive loss


	For the years ended December 31,
	2016			2017			2018
	RMB			RMB			RMB			US$
Net loss		(633,598	)		(772,730	)		(205,065	)		(29,827	)
Other comprehensive income (loss), net of tax of nil:
Foreign currency translation adjustments, net of tax of nil		142,526			(120,963	)		88,652			12,894

Other comprehensive income (loss), net of tax of nil:		142,526			(120,963	)		88,652			12,894

Comprehensive loss		(491,072	)		(893,693	)		(116,413	)		(16,933	)

Comprehensive loss attributable to the Company’s ordinary shareholders		(491,072	)		(893,693	)		(116,413	)		(16,933	)

Condensed Statements of Cash Flows

Condensed

statements of cash flows


	For the years ended December 31,
	2016 (As adjusted)			2017 (As adjusted)			2018
	RMB			RMB			RMB			US$
Net cash used in operating activities		(78,567	)		(18,324	)		(166,068	)		(24,154	)
Net cash used in investing activities		(617,613	)		(1,291,042	)		(203,651	)		(29,620	)
Net cash generated from (used in) financing activities		2,254,577			(130,187	)		43,145			6,275

Net increase (decrease) in cash and cash equivalents and restricted cash		1,558,397			(1,439,553	)		(326,574	)		(47,499	)
Cash and cash equivalents and restricted cash at beginning of the year		798,200			2,356,597			917,044			133,379

Cash and cash equivalents and restricted cash at end of the year		2,356,597			917,044			590,470			85,880

Summary of Company Subsidiaries and Its Consolidated Variable Interest Entities (Detail)

12 Months Ended

Dec. 31, 2018

21ViaNet Group Limited ("21Vianet HK") | Subsidiaries

Business Acquisition [Line Items]

Date of incorporation/ Acquisition

May 25, 2007

Place of incorporation

Hong Kong

Percentage of direct ownership by the Company

100.00%

Principal activities

Investment holding

21Vianet Data Center Co., Ltd. ("21Vianet China") | Subsidiaries

Business Acquisition [Line Items]

Date of incorporation/ Acquisition

Jun. 12, 2000

^[1]

Place of incorporation

PRC

^[1]

Percentage of direct ownership by the Company

100.00%

^[1]

Principal activities

Provision of technical and consultation services and rental of long-lived assets

^[1]

21Vianet (Foshan) Technology Co., Ltd. ("FS Technology") | Subsidiaries

Business Acquisition [Line Items]

Date of incorporation/ Acquisition

Dec. 20, 2011

^[1]

Place of incorporation

PRC

^[1]

Percentage of direct ownership by the Company

100.00%

^[1]

Principal activities

Trading of network equipment, provision of technical and internet data center services

^[1]

21Vianet Anhui Suzhou Technology Co., Ltd.("SZ Technology") | Subsidiaries

Business Acquisition [Line Items]

Date of incorporation/ Acquisition

Nov. 16, 2011

^[1]

Place of incorporation

PRC

^[1]

Percentage of direct ownership by the Company

100.00%

^[1]

Principal activities

Trading of network equipment

^[1]

21Vianet Hangzhou Information Technology Co.,Ltd. ("HZ Technology") | Subsidiaries

Business Acquisition [Line Items]

Date of incorporation/ Acquisition

Mar. 04, 2013

^[1]

Place of incorporation

PRC

^[1]

Percentage of direct ownership by the Company

100.00%

^[1]

Principal activities

Provision of internet data center services

^[1]

21Vianet Mobile Limited ("21V Mobile") | Subsidiaries

Business Acquisition [Line Items]

Date of incorporation/ Acquisition

Apr. 30, 2013

Place of incorporation

Hong Kong

Percentage of direct ownership by the Company

100.00%

Principal activities

Investment holding and provision of telecommunication services

Joytone Infotech Co., Ltd. ("SZ Zhuoaiyi") | Subsidiaries

Business Acquisition [Line Items]

Date of incorporation/ Acquisition

Apr. 30, 2013

^[1]

Place of incorporation

PRC

^[1]

Percentage of direct ownership by the Company

100.00%

^[1]

Principal activities

Provision of technical and consultation services

^[1]

21Vianet Ventures Limited (Ventures) | Subsidiaries

Business Acquisition [Line Items]

Date of incorporation/ Acquisition

Mar. 06, 2014

Place of incorporation

Hong Kong

Percentage of direct ownership by the Company

100.00%

Principal activities

Investment holding

Abitcool (China) Broadband Inc. ("aBitCool DG") | Subsidiaries

Business Acquisition [Line Items]

Date of incorporation/ Acquisition

Jun. 13, 2014

^[1]

Place of incorporation

PRC

^[1]

Percentage of direct ownership by the Company

100.00%

^[1]

Principal activities

Dormant company

^[1]

Diyixian.com Limited ("Diyixian.com") | Subsidiaries

Business Acquisition [Line Items]

Date of incorporation/ Acquisition

Aug. 10, 2014

Place of incorporation

Hong Kong

Percentage of direct ownership by the Company

100.00%

Principal activities

Provision of virtual private network services

21Vianet Zhuhai Financial Leasing Limited | Subsidiaries

Business Acquisition [Line Items]

Date of incorporation/ Acquisition

Apr. 09, 2015

^[1]

Place of incorporation

PRC

^[1]

Percentage of direct ownership by the Company

100.00%

^[1]

Principal activities

Provision of financial leasing business services

^[1]

21Vianet DRP Investment Holdings Limited [Member] | Subsidiaries

Business Acquisition [Line Items]

Date of incorporation/ Acquisition

Jan. 10, 2017

Place of incorporation

Hong Kong

Percentage of direct ownership by the Company

100.00%

Principal activities

Investment holding

Shihua DC Investment Holdings Limited. | Subsidiaries

Business Acquisition [Line Items]

Date of incorporation/ Acquisition

Mar. 14, 2017

Place of incorporation

Cayman

Percentage of direct ownership by the Company

51.00%

Principal activities

Investment holding

21Vianet (Xi'an) Technology Co., Ltd. ("Xi'an Tech") | Subsidiaries

Business Acquisition [Line Items]

Date of incorporation/ Acquisition

Jul. 05, 2012

^[1]

Place of incorporation

PRC

^[1]

Percentage of direct ownership by the Company

51.00%

^[1]

Principal activities

Provision of technical and internet data center services

^[1]

Foshan Zhuoyi Intelligence Date Co., Ltd. ("FS Zhuoyi") | Subsidiaries

Business Acquisition [Line Items]

Date of incorporation/ Acquisition

Jul. 07, 2016

^[1]

Place of incorporation

PRC

^[1]

Percentage of direct ownership by the Company

51.00%

^[1]

Principal activities

Provision of internet data center services

^[1]

Dermot Holding Limited [Member] | Subsidiaries

Business Acquisition [Line Items]

Date of incorporation/ Acquisition

Aug. 08, 2014

^[2]

Place of incorporation

British Virgin Islands

^[2]

Percentage of direct ownership by the Company

100.00%

^[2]

Principal activities

Investment holding

^[2]

Beijing Yiyun Network Technology Co., Ltd. (formerly known as [Beijing aBitCool Network Technology Co., Ltd.]) ("21Vianet Technology") | Variable Interest Entities

Business Acquisition [Line Items]

Date of incorporation/ Acquisition

Oct. 22, 2002

^[1],[3]

Place of incorporation

PRC

^[1],[3]

Percentage of direct ownership by the Company

0.00%

^[1],[3]

Principal activities

Provision of internet data center services

^[1],[3]

Beijing iJoy Information Technology Co., Ltd. ("BJ iJoy") | Variable Interest Entities

Business Acquisition [Line Items]

Date of incorporation/ Acquisition

Apr. 30, 2013

^[1],[3]

Place of incorporation

PRC

^[1],[3]

Percentage of direct ownership by the Company

0.00%

^[1],[3]

Principal activities

Provision of internet data center, content delivery network services

^[1],[3]

WiFire Network Technology (Beijing) Co., Ltd. (formerly known as aBitCool Small Micro Network Technology (BJ) Co., Ltd.) (WiFire Network) | Variable Interest Entities

Business Acquisition [Line Items]

Date of incorporation/ Acquisition

Apr. 01, 2014

^[1],[3]

Place of incorporation

PRC

^[1],[3]

Percentage of direct ownership by the Company

0.00%

^[1],[3]

Principal activities

Provision of telecommunication services

^[1],[3]

Beijing 21Vianet Broad Band Data Center Co., Ltd. ("21Vianet Beijing") | Variable Interest Entities | Held Directly by 21 Vianet Technology

Business Acquisition [Line Items]

Date of incorporation/ Acquisition

Mar. 15, 2006

^[1],[3]

Place of incorporation

PRC

^[1],[3]

Percentage of direct ownership by the Company

0.00%

^[1],[3]

Principal activities

Provision of internet data center services

^[1],[3]

21Vianet (Xi'an) Information Outsourcing Industry Park Services Co., Ltd. ("Xi'an Sub") | Variable Interest Entities | Held Directly by 21 Vianet Beijing

Business Acquisition [Line Items]

Date of incorporation/ Acquisition

Jun. 23, 2008

^[1],[3]

Place of incorporation

PRC

^[1],[3]

Percentage of direct ownership by the Company

0.00%

^[1],[3]

Principal activities

Provision of internet data center services

^[1],[3]

Langfang Xunchi Computer Data Processing Co., Ltd. ("LF Xunchi") | Variable Interest Entities | Held Directly by 21 Vianet Beijing

Business Acquisition [Line Items]

Date of incorporation/ Acquisition

Dec. 19, 2011

^[1],[3]

Place of incorporation

PRC

^[1],[3]

Percentage of direct ownership by the Company

0.00%

^[1],[3]

Principal activities

Dormant company

^[1],[3]

Shanghai Blue Cloud Technology Co., Ltd. ("SH Blue Cloud") | Variable Interest Entities | Held Directly by 21 Vianet Beijing

Business Acquisition [Line Items]

Date of incorporation/ Acquisition

Mar. 21, 2013

^[1],[3]

Place of incorporation

PRC

^[1],[3]

Percentage of direct ownership by the Company

0.00%

^[1],[3]

Principal activities

Provision of Office 365 and Windows Azure platform services

^[1],[3]

Beijing Yichengtaihe Investment Co., Ltd | Variable Interest Entities | Held Directly by 21 Vianet Beijing

Business Acquisition [Line Items]

Date of incorporation/ Acquisition

Sep. 30, 2014

^[1],[3]

Place of incorporation

PRC

^[1],[3]

Percentage of direct ownership by the Company

0.00%

^[1],[3]

Principal activities

Provision of internet data center services

^[1],[3]

Beijing Hongyuan Network Technology Co., Ltd [Member] | Variable Interest Entities | Held Directly by 21 Vianet Beijing | Subsidiaries

Business Acquisition [Line Items]

Date of incorporation/ Acquisition

Dec. 08, 2014

^[1],[3],[4]

Place of incorporation

PRC

^[1],[3],[4]

Percentage of direct ownership by the Company

0.00%

^[1],[3],[4]

Principal activities

Provision of internet data center services

^[1],[3],[4]

Guangzhou Lianyun Big Data Co Ltd [Member] | Variable Interest Entities | Held Directly by 21 Vianet Beijing | Subsidiaries

Business Acquisition [Line Items]

Date of incorporation/ Acquisition

Apr. 14, 2016

^[1],[3]

Place of incorporation

PRC

^[1],[3]

Percentage of direct ownership by the Company

0.00%

^[1],[3]

Principal activities

Provision of internet data center services

^[1],[3]

Shenzhen Diyixian Telecommunication Co., Ltd [Member] | Variable Interest Entities | Held Directly by 21 Vianet Beijing | Subsidiaries

Business Acquisition [Line Items]

Date of incorporation/ Acquisition

Aug. 10, 2014

^[1]

Place of incorporation

PRC

^[1]

Percentage of direct ownership by the Company

100.00%

^[1]

Principal activities

Provision of virtual private network services

^[1]

[1]	Collectively, the "PRC Subsidiaries".
[2]	On August 10, 2014, the Company and its subsidiary, LF Xunchi, acquired 100% equity interest Dermot BVI and its subsidiaries (collectively referred to as "Dermot Entities").
[3]	Collectively, the "Consolidated VIEs".
[4]	On August 15, 2018, the Company through its subsidiary, 21Vianet Beijing disposed 49% equity interest of BJ Hongyuan to a third party.

Summary of Company Subsidiaries and Its Consolidated Variable Interest Entities (Parenthetical) (Detail)	Aug. 15, 2018	Aug. 10, 2014
Dermot Entities
Business Acquisition [Line Items]
Business acquisition, equity interests acquired		100.00%
Third Party
Business Acquisition [Line Items]
Business acquisition, equity interests transferred	49.00%

Organization - Additional Information (Detail)		1 Months Ended	12 Months Ended
Organization - Additional Information (Detail)	Dec. 19, 2016	Jan. 31, 2011 CNY (¥)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2018 USD ($) Entity	Dec. 31, 2018 CNY (¥) Entity	Mar. 31, 2017
Organization [Line Items]
Number of additional VIEs controlled through Primary Beneficiaries \| Entity				2	2
Assets pledged as collateral				$ 44,069,000	¥ 302,999,000
Unconsolidated VIE's carrying amount of assets				0	0
Unconsolidated VIE's carrying amount of liabilities				0	0
Maximum exposure to loss related to arrangements with variable interest entity				$ 6,755,000	¥ 46,445,000
Internet Data Center Services
Organization [Line Items]
Equity interest percentage by parent						51.00%
Warburg Pincus
Organization [Line Items]
Equity interest percentage				49.00%	49.00%	49.00%
Option Agreement
Organization [Line Items]
Exclusive option price			¥ 1
Agreement agreement between 21Vianet China and the 21Vianet Technology, term	10 years		10 years
Agreement agreement between 21Vianet China and the 21Vianet Technology, expiration date	Dec. 18, 2026		Dec. 18, 2016
Technical Consulting and Service Agreement
Organization [Line Items]
Agreement agreement between 21Vianet China and the 21Vianet Technology, term	10 years		10 years
Agreement agreement between 21Vianet China and the 21Vianet Technology, expiration date	Dec. 18, 2026		Dec. 18, 2016
Service fee per hour			¥ 1,000
Loan Agreement \| Shareholders \| Loan one
Organization [Line Items]
Loan facility provided to related parties		¥ 7,000,000
Loan Agreement \| Shareholders \| Loan Two
Organization [Line Items]
Loan facility provided to related parties		¥ 3,000,000

Consolidated VIE Included in Accompanying Consolidated Financial Statements (Detail)
¥ in Thousands, $ in Thousands

12 Months Ended

Dec. 31, 2018

USD ($)

Dec. 31, 2018

CNY (¥)

Dec. 31, 2017

CNY (¥)

Dec. 31, 2016

CNY (¥)

Dec. 31, 2018

CNY (¥)

Dec. 31, 2017

USD ($)

Dec. 31, 2017

CNY (¥)

Dec. 31, 2015

CNY (¥)

Current assets:

Cash and cash equivalents

$ 343,038

¥ 1,297,418

¥ 2,358,556

¥ 1,949,631

Restricted cash

38,574

1,963,561

265,214

242,494

Short-term investments

35,636

245,014

548,890

Prepaid expenses and other current assets

168,385

1,157,740

933,750

Amounts due from related parties

18,245

125,446

114,256

Total current assets

680,402

4,678,109

4,245,542

Non-current assets:

Property and equipment, net

586,320

4,031,242

3,319,424

Intangible assets, net

51,678

977,341

355,313

401,115

Land use rights, net

21,452

147,493

163,671

Goodwill

143,921

1,755,970

989,530

$ 143,921

989,530

¥ 1,755,970

Restricted cash

5,418

33,544

37,251

3,344

Deferred tax assets

23,190

159,441

172,818

Amounts due from related parties

5,007

34,424

20,210

Other non-current assets

25,248

173,591

81,581

Long-term investments

79,168

544,323

510,926

Total non-current assets

941,402

6,472,608

5,662,619

Total assets

1,621,804

11,150,717

9,908,161

Current liabilities:

Short-term bank borrowings

7,272

50,000

Accounts and notes payable

56,652

389,508

252,892

Accrued expenses and other payables

95,894

659,320

657,133

Advance from customers

97,453

670,037

403,244

Deferred revenue

8,400

57,754

55,753

Income tax payable

1,907

13,111

13,309

Amounts due to related parties

7,611

52,328

55,675

Current portion of capital lease obligations

31,953

219,695

201,315

Deferred government grants

607

4,173

4,574

Total current liabilities

318,699

2,191,210

1,764,184

Non-current liabilities:

Amounts due to related parties-non current

73,373

504,478

Non-current portion of capital lease obligations

111,409

765,993

600,882

Unrecognized tax benefits

971

6,677

16,511

Deferred tax liabilities

22,939

157,720

190,873

Deferred government grants

1,690

11,619

17,861

Total non-current liabilities

523,063

3,596,323

2,942,973

Total liabilities

841,762

5,787,533

4,707,157

Net revenues

494,660

¥ 3,401,037

¥ 3,392,705

3,641,774

Net (loss) profit

(27,161)

(186,736)

(917,644)

(931,922)

Net cash generated from operating activities

102,534

704,966

487,202

57,569

Net cash (used in) generated from investing activities

(44,337)

(304,846)

(833,307)

(841,017)

Net cash generated from (used in) financing activities

(2,896)

(19,901)

(612,651)

1,908,883

Variable Interest Entity, Primary Beneficiary

Current assets:

Cash and cash equivalents

79,837

548,921

233,673

Restricted cash

29,540

203,103

149,375

Accounts receivable (net of allowance for doubtful debt of RMB70,627 and RMB69,723 (US$10,141) as of December 31, 2017 and 2018, respectively)

54,616

375,515

342,276

Short-term investments

13,672

94,000

Prepaid expenses and other current assets

147,417

1,013,563

809,546

Amounts due from related parties

17,995

123,726

86,824

Total current assets

343,077

2,358,828

1,621,694

Non-current assets:

Property and equipment, net

451,457

3,103,995

2,331,139

Intangible assets, net

6,853

47,121

45,203

Land use rights, net

8,738

60,078

74,162

Goodwill

44,018

302,647

302,956

Restricted cash

4,906

33,729

Deferred tax assets

22,749

156,412

169,224

Amounts due from related parties

1,966

13,514

Other non-current assets

23,619

162,392

67,517

Long-term investments

31,853

219,005

355,894

Total non-current assets

596,159

4,098,893

3,346,095

Total assets

939,236

6,457,721

4,967,789

Current liabilities:

Short-term bank borrowings

7,272

50,000

Accounts and notes payable

37,532

258,048

157,970

Accrued expenses and other payables

57,104

392,619

368,190

Advance from customers

97,453

670,037

403,244

Deferred revenue

7,421

51,026

49,699

Income tax payable

1,239

8,519

7,400

Amounts due to inter-companies

^[1]

307,919

2,117,097

1,863,780

Amounts due to related parties

7,529

51,763

16,053

Current portion of capital lease obligations

31,953

219,695

201,315

Current portion of long-term bank borrowings

10,950

75,284

70,289

Deferred government grants

607

4,173

4,574

Total current liabilities

566,978

3,898,261

3,192,514

Non-current liabilities:

Amounts due to inter-companies

^[1]

148,494

1,020,972

Amounts due to related parties-non current

73,373

504,478

Non-current portion of long-term bank borrowings

16,290

112,000

187,638

Non-current portion of capital lease obligations

123,960

852,287

687,176

Unrecognized tax benefits

718

4,938

13,225

Deferred tax liabilities

12,300

84,568

109,339

Deferred government grants

1,690

11,619

17,861

Total non-current liabilities

376,825

2,590,862

2,036,211

Total liabilities

943,803

¥ 6,489,123

¥ 5,228,725

Net revenues

368,388

2,532,854

2,578,893

2,938,319

Net (loss) profit

7,706

52,986

(567,395)

(674,685)

Net cash generated from operating activities

100,883

693,620

448,051

106,803

Net cash (used in) generated from investing activities

19,279

132,522

(604,507)

(470,955)

Net cash generated from (used in) financing activities

(61,590)

(423,467)

230,921

145,678

Net (decrease) increase in cash and cash equivalents and restricted cash

$ 58,572

¥ 402,705

¥ 74,465

¥ (218,474)

[1]	Amounts due to inter-companies consist of intercompany payables to the other companies within the Company for the purchase of telecommunication resources and fixed assets on behalf of the Consolidated VIEs.

Consolidated VIE Included in Accompanying Consolidated Financial Statements (Parenthetical) (Detail) ¥ in Thousands, $ in Thousands	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)
Variable Interest Entity, Primary Beneficiary
Variable Interest Entity [Line Items]
Accounts receivable, allowance for doubtful accounts	$ 10,141	¥ 69,723	¥ 70,627

Summary of Significant Accounting Policies - Additional Information (Detail) $ in Thousands		1 Months Ended		12 Months Ended
	Oct. 01, 2016 Segment	Sep. 30, 2017	Sep. 30, 2016 Segment	Dec. 31, 2018 USD ($) Segment Reporting_unit shares	Dec. 31, 2018 CNY (¥) Segment Reporting_unit shares	Dec. 31, 2017 CNY (¥) Segment shares	Jun. 29, 2017 USD ($)	Dec. 31, 2016 CNY (¥) shares	Dec. 31, 2018 CNY (¥)
Significant Accounting Policies [Line Items]
Official exchange rate of foreign currency remeasured (RMB per one U.S. dollar)				6.8755					6.8755
Internal use software development costs, Amount capitalized				$ 886		¥ 9,238,000		¥ 12,781,000	¥ 6,093,000
Number of reporting units \| Reporting_unit				1	1
Cash flows estimated growth rate after six years using terminal value		3.00%
Discount rate used in the valuations based on weighted average cost of capital		13.00%		13.00%				13.00%	13.00%
Discounted cash flow projection period		5 years						8 years
Impairment losses pursuant to the goodwill tests					¥ 0	766,440,000		¥ 0
Long-lived assets impairment					0
Deferred revenue				$ 8,400		55,753,000			¥ 57,754,000
Revenue recognized				6,617	45,492,000
Advertising expense				$ 1,159	¥ 7,968,000	¥ 7,773,000		¥ 20,420,000
Share Repurchase Plan, shares repurchased (in shares) \| shares				0	0	3,448,482		815,525
Share Repurchase Plan, share value						¥ 133,126,000		¥ 42,665,000
Number of reportable segments \| Segment	2		1	1	1	1
Aipu Group
Significant Accounting Policies [Line Items]
Discounted cash flow projection period				7 years	7 years
Long-lived assets impairment						¥ 170,695,000
WiFire Group Inc. ("WiFire Group")
Significant Accounting Policies [Line Items]
Discounted cash flow projection period				5 years	5 years
Long-lived assets impairment						¥ 231,113,000
American Depository Shares
Significant Accounting Policies [Line Items]
Share Repurchase Plan, period							12 months
Share Repurchase Plan, shares repurchased (in shares) \| shares				0	0	3,448,482		815,525
Share Repurchase Plan, share value					¥ 0	¥ 133,126,000		¥ 42,665,000
Maximum \| American Depository Shares
Significant Accounting Policies [Line Items]
Share Repurchase Plan, value \| $							$ 200,000
Minimum \| Capital Leases
Significant Accounting Policies [Line Items]
Capital lease recognition condition, lease term as a percentage of estimated remaining economic life				75.00%	75.00%
Capital lease recognition condition, minimum lease payments at the beginning of the lease term as a percentage of the fair value of the leased property				90.00%	90.00%

Estimated Useful Lives of Property and Equipment (Detail)	12 Months Ended
	Dec. 31, 2018
Property \| Minimum
Property, Plant and Equipment [Line Items]
Property and equipment, estimated useful life	25 years
Property \| Maximum
Property, Plant and Equipment [Line Items]
Property and equipment, estimated useful life	46 years
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, estimated useful life	Over the shorter of lease term or the estimated useful lives of the assets
Optical Fibers \| Minimum
Property, Plant and Equipment [Line Items]
Property and equipment, estimated useful life	10 years
Optical Fibers \| Maximum
Property, Plant and Equipment [Line Items]
Property and equipment, estimated useful life	20 years
Computer and network equipment \| Minimum
Property, Plant and Equipment [Line Items]
Property and equipment, estimated useful life	1 year
Computer and network equipment \| Maximum
Property, Plant and Equipment [Line Items]
Property and equipment, estimated useful life	10 years
Office equipment \| Minimum
Property, Plant and Equipment [Line Items]
Property and equipment, estimated useful life	1 year
Office equipment \| Maximum
Property, Plant and Equipment [Line Items]
Property and equipment, estimated useful life	8 years
Motor vehicles \| Minimum
Property, Plant and Equipment [Line Items]
Property and equipment, estimated useful life	4 years
Motor vehicles \| Maximum
Property, Plant and Equipment [Line Items]
Property and equipment, estimated useful life	8 years

Weighted Average Useful Lives of Intangible Assets (Detail)

12 Months Ended

Dec. 31, 2018

Purchased software

Finite-Lived Intangible Assets [Line Items]

Estimated useful life of intangible assets

6 years 6 months

Radio Spectrum License

Finite-Lived Intangible Assets [Line Items]

Estimated useful life of intangible assets

15 years

Contract Backlog

Finite-Lived Intangible Assets [Line Items]

Estimated useful life of intangible assets

4 years 10 months 24 days

^[1]

Customer Relationships

Finite-Lived Intangible Assets [Line Items]

Estimated useful life of intangible assets

8 years 9 months 18 days

^[1]

Supplier Relationships

Finite-Lived Intangible Assets [Line Items]

Estimated useful life of intangible assets

10 years

^[1]

Licenses

Finite-Lived Intangible Assets [Line Items]

Estimated useful life of intangible assets

15 years

^[1]

Trade Names

Finite-Lived Intangible Assets [Line Items]

Estimated useful life of intangible assets

20 years

^[1]

Platform Software

Finite-Lived Intangible Assets [Line Items]

Estimated useful life of intangible assets

5 years

^[1]

Non-compete agreement

Finite-Lived Intangible Assets [Line Items]

Estimated useful life of intangible assets

5 years

^[1]

Internal-use Software

Finite-Lived Intangible Assets [Line Items]

Estimated useful life of intangible assets

4 years 10 months 24 days

[1]	Acquired in the acquisitions of subsidiaries

Summary of Impairment Charges Associated with Long-Lived Assets and Acquired Intangibles (Detail) - CNY (¥) ¥ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Asset Impairment Charges [Abstract]
Impairment of equipment	¥ 237,956	¥ 238,144
Impairment of intangible assets	¥ 163,852	¥ 154,803

Interest Expenses (Detail) ¥ in Thousands, $ in Thousands	12 Months Ended
Interest Expenses (Detail) ¥ in Thousands, $ in Thousands	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)	Dec. 31, 2016 CNY (¥)
Supplemental Income Statement Elements [Abstract]
Interest expense and amortization cost of bonds	$ 21,831	¥ 150,098	¥ 63,354	¥ 113,367
Interest expense on bank borrowings	2,820	19,395	87,916	46,377
Interest expense on capital lease	11,626	79,935	63,757	66,687
Total interest expenses	36,277	249,428	215,027	226,431
Less: Total interest expenses capitalized	(1,943)	(13,362)	(29,714)	(27,842)
Interest expenses, net	$ 34,334	¥ 236,066	¥ 185,313	¥ 198,589

Concentration of Risks - Additional Information (Detail) ¥ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($) Customer	Dec. 31, 2017 USD ($) Customer	Dec. 31, 2016 Customer	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)
Concentration Risk [Line Items]
Depreciation of RMB against US$	5.00%	(5.80%)	6.80%
Customer Concentration Risk
Concentration Risk [Line Items]
Number of customers who contributed more than 3% of Company's revenue	0	0	0
Cabinet and Bandwidth Supply \| Supplier Concentration Risk
Concentration Risk [Line Items]
Concentration of risk, percentage	19.00%	21.00%	19.00%
Bandwidth and Cabinet Resources \| Customer Concentration Risk
Concentration Risk [Line Items]
Concentration of risk, percentage	4.00%	2.00%	4.00%
Bandwidth and Cabinet Resources \| Customer Concentration Risk \| Largest single customer \| Maximum
Concentration Risk [Line Items]
Concentration of risk, percentage	12.00%
PRC \| Credit Concentration Risk
Concentration Risk [Line Items]
Cash and cash equivalents, restricted cash and short-term investments, held at major institutions	$ 164,583			¥ 1,131,588	¥ 640,001
Outside the PRC \| Credit Concentration Risk
Concentration Risk [Line Items]
Cash and cash equivalents, restricted cash and short-term investments, held at major institutions	$ 258,083	$ 323,434		¥ 1,774,447

Disposal of Subsidiaries- Additional Information (Detail)	1 Months Ended	12 Months Ended
	Sep. 30, 2017 CNY (¥) Subsidiary shares	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)	Dec. 31, 2016 CNY (¥)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of wholly owned subsidiaries \| Subsidiary	6
Impairment losses of long-lived assets			¥ 401,808,000
Impairment losses of goodwill		¥ 0	766,440,000	¥ 0
Gain on disposal of subsidiaries			¥ 497,036,000
WiFire Group Inc. ("WiFire Group")
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Equity interest transferred	66.67%
Consideration price	¥ 6
Equity interest	33.33%
Aipu Group
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Consideration price	¥ 1
Number of shares transferred \| shares	2
Ownership percentage before transaction	50.00%
Description of ownership after transfer of shares	The Company's ownership in SC Aipu changed from 50% equity interest plus one share to 50% equity interest minus one share and lost control.
Tibet Xingtao Culture Communications Co., Ltd. [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Equity interest transferred			50.00%
Consideration price			¥ 1

Accounts and Notes Receivable and Allowance for Doubtful Debt (Detail) ¥ in Thousands, $ in Thousands	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 USD ($)	Dec. 31, 2017 CNY (¥)	Dec. 31, 2016 CNY (¥)
Receivables [Abstract]
Accounts receivable	$ 86,200	¥ 592,669		¥ 526,747
Notes receivable	379	2,606		2,720
Allowance for doubtful debt	(10,322)	(70,970)	$ (10,712)	(73,656)	¥ (80,910)
Accounts and notes receivable (net of allowance for doubtful debt of RMB73,656 and RMB70,970 (US$10,322) as of December 31, 2017 and 2018, respectively)	$ 76,257	¥ 524,305		¥ 455,811

Analysis of Allowance for Doubtful Debt (Detail) ¥ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)
Receivables [Abstract]
Balance at beginning of the year	$ 10,712	¥ 73,656	¥ 80,910
Additional provision charged to expense	46	315	69,553
Write-off of accounts receivable	(436)	(3,001)	(19,766)
Provision included in disposed subsidiaries			(57,041)
Balance at end of the year	$ 10,322	¥ 70,970	¥ 73,656

Short Term Investments (Detail) ¥ in Thousands, $ in Thousands	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)
Short-term investments
Investment [Line Items]
Time deposits	$ 35,636	¥ 245,014	¥ 548,890

Short-Term Investments - Additional Information (Detail) ¥ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)	Dec. 31, 2016 CNY (¥)
Investment [Line Items]
Investments, interest income	$ 6,572	¥ 45,186	¥ 32,925	¥ 21,078
Short-term investments
Investment [Line Items]
Investments, interest income	$ 1,062	¥ 7,303	¥ 4,021	¥ 1,148

Prepaid Expenses and Other Current Assets (Detail) ¥ in Thousands, $ in Thousands	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)
Prepaid Expense and Other Assets [Abstract]
Prepaid expenses	$ 82,279	¥ 565,710	¥ 380,869
Staff advances	1,561	10,730	6,735
Interest receivables	1,751	12,037	17,644
Tax recoverables	61,327	421,654	376,642
Deposits	5,814	39,971	30,669
Prepayment for share repurchase plan			42,710
Loan to third parties	8,567	58,909	60,805
Other receivables	7,086	48,729	17,676
Prepaid expenses and other current assets	$ 168,385	¥ 1,157,740	¥ 933,750

Property and Equipment Including Those Held Under Capital Leases (Detail) ¥ in Thousands, $ in Thousands	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)
Property, Plant and Equipment [Line Items]
Property and Equipment, gross	$ 744,019	¥ 5,115,505	¥ 4,096,090
Less: Accumulated depreciation	(272,073)	(1,870,640)	(1,326,511)
Property Plant And Equipment Net Excluding Construction In Progress	471,946	3,244,865	2,769,579
Construction-in-progress	114,374	786,377	549,845
Property and Equipment, net	586,320	4,031,242	3,319,424
Property
Property, Plant and Equipment [Line Items]
Property and Equipment, gross	109,566	753,319	467,312
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and Equipment, gross	135,684	932,896	789,734
Computer and network equipment
Property, Plant and Equipment [Line Items]
Property and Equipment, gross	474,196	3,260,336	2,681,759
Optical Fibers
Property, Plant and Equipment [Line Items]
Property and Equipment, gross	20,758	142,723	142,723
Office equipment
Property, Plant and Equipment [Line Items]
Property and Equipment, gross	3,547	24,390	12,671
Motor vehicles
Property, Plant and Equipment [Line Items]
Property and Equipment, gross	$ 268	¥ 1,841	¥ 1,891

Property and Equipment Net - Additional Information (Detail) ¥ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)	Dec. 31, 2016 CNY (¥)
Property, Plant and Equipment [Line Items]
Depreciation expense	$ 82,393	¥ 566,491	¥ 523,500	¥ 480,105
Assets held under capital leases
Property, Plant and Equipment [Line Items]
Depreciation expense	$ 24,764	¥ 170,264	¥ 92,920	¥ 100,157

Depreciation Expense (Detail) ¥ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)	Dec. 31, 2016 CNY (¥)
Property, Plant and Equipment [Line Items]
Depreciation expenses	$ 82,393	¥ 566,491	¥ 523,500	¥ 480,105
Cost of Revenues
Property, Plant and Equipment [Line Items]
Depreciation expenses	75,746	520,791	458,655	397,014
Selling and Marketing Expense
Property, Plant and Equipment [Line Items]
Depreciation expenses	144	986	3,188	3,759
General and Administrative Expense
Property, Plant and Equipment [Line Items]
Depreciation expenses	4,178	28,727	41,675	45,746
Research and Development Expense
Property, Plant and Equipment [Line Items]
Depreciation expenses	$ 2,325	¥ 15,987	¥ 19,982	¥ 33,586

Carrying Amounts of Property and Equipment Held Under Capital Leases (Detail) ¥ in Thousands, $ in Thousands	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)
Capital Leased Assets [Line Items]
Property and Equipment Held Under Capital Leases, gross	$ 178,569	¥ 1,227,752	¥ 1,005,608
Less: Accumulated depreciation	(42,408)	(291,579)	(262,601)
Property and Equipment Held Under Capital Leases, gross	136,161	936,173	743,007
Construction-in-progress	114,374	786,377	549,845
Property and Equipment Held Under Capital Leases, net	219,940	1,512,195	873,199
Property
Capital Leased Assets [Line Items]
Property and Equipment Held Under Capital Leases, gross	53,138	365,353	365,353
Computer and network equipment
Capital Leased Assets [Line Items]
Property and Equipment Held Under Capital Leases, gross	104,673	719,676	497,532
Optical Fibers
Capital Leased Assets [Line Items]
Property and Equipment Held Under Capital Leases, gross	20,758	142,723	142,723
Capital Lease
Capital Leased Assets [Line Items]
Construction-in-progress	$ 83,779	¥ 576,022	¥ 130,192

Carrying Amounts of Property and Equipment Pledged to Secure Banking Borrowings (Detail) ¥ in Thousands, $ in Thousands	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)
Property, Plant and Equipment [Line Items]
Assets pledged as collateral	$ 44,069	¥ 302,999
Property
Property, Plant and Equipment [Line Items]
Assets pledged as collateral	20,419	140,393	¥ 143,893
Computer and network equipment
Property, Plant and Equipment [Line Items]
Assets pledged as collateral	21,258	146,159	200,954
Office equipment
Property, Plant and Equipment [Line Items]
Assets pledged as collateral	$ 6	¥ 44	¥ 85

Summary of Intangible Assets (Detail) ¥ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)	Dec. 31, 2016 CNY (¥)
Finite-Lived Intangible Assets [Line Items]
Beginning Balance		¥ 401,115	¥ 977,341
Additions		24,837	20,311
Disposals		(6,772)	(280,397)
Foreign currency translation difference		4,248	(8,686)
Amortization expense	$ (9,907)	(68,115)	(143,602)	¥ (183,964)
Impairment			(163,852)	(154,803)
Ending Balance	51,678	355,313	401,115	977,341
Purchased software
Finite-Lived Intangible Assets [Line Items]
Beginning Balance		50,629	73,445
Additions		18,744	11,073
Disposals		(6,772)	(5,973)
Foreign currency translation difference		364	(905)
Amortization expense		(15,711)	(27,011)
Ending Balance	6,873	47,254	50,629	73,445
Radio Spectrum License
Finite-Lived Intangible Assets [Line Items]
Beginning Balance		77,141	91,568
Foreign currency translation difference		3,884	(7,781)
Amortization expense		(8,117)	(6,646)
Ending Balance	10,604	72,908	77,141	91,568
Network Use Right
Finite-Lived Intangible Assets [Line Items]
Beginning Balance			15,834
Disposals			(15,086)
Amortization expense			(748)
Ending Balance				15,834
Contract Backlog
Finite-Lived Intangible Assets [Line Items]
Beginning Balance		11,750	18,338
Amortization expense		(6,588)	(6,588)
Ending Balance	751	5,162	11,750	18,338
Customer Relationships
Finite-Lived Intangible Assets [Line Items]
Beginning Balance		137,882	412,775
Disposals			(134,706)
Amortization expense		(24,921)	(52,992)
Impairment			(87,195)
Ending Balance	16,429	112,961	137,882	412,775
Licenses
Finite-Lived Intangible Assets [Line Items]
Beginning Balance		4,268	12,557
Disposals			(4,000)
Amortization expense		(385)	(757)
Impairment			(3,532)
Ending Balance	565	3,883	4,268	12,557
Supplier Relationships
Finite-Lived Intangible Assets [Line Items]
Beginning Balance		20,144	88,443
Disposals			(7,227)
Amortization expense		(3,074)	(19,304)
Impairment			(41,768)
Ending Balance	2,483	17,070	20,144	88,443
Trade Names
Finite-Lived Intangible Assets [Line Items]
Beginning Balance		96,404	168,385
Disposals			(37,270)
Amortization expense		(5,813)	(12,217)
Impairment			(22,494)
Ending Balance	13,176	90,591	96,404	168,385
Platform Software
Finite-Lived Intangible Assets [Line Items]
Beginning Balance		683	3,924
Amortization expense		(683)	(3,241)
Ending Balance			683	3,924
Non - Complete Agreement
Finite-Lived Intangible Assets [Line Items]
Beginning Balance		154	8,903
Disposals			(4,297)
Amortization expense		(110)	(3,347)
Impairment			(1,105)
Ending Balance	6	44	154	8,903
Internal-use Software
Finite-Lived Intangible Assets [Line Items]
Beginning Balance		2,060	40,006
Additions		6,093	9,238
Disposals			(41,660)
Amortization expense		(2,713)	(5,524)
Ending Balance	$ 791	¥ 5,440	2,060	40,006
Property management relationship
Finite-Lived Intangible Assets [Line Items]
Beginning Balance			43,163
Disposals			(30,178)
Amortization expense			(5,227)
Impairment			¥ (7,758)
Ending Balance				¥ 43,163

Intangible Assets Net - Additional Information (Detail) ¥ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)	Dec. 31, 2016 CNY (¥)
Finite-Lived Intangible Assets [Line Items]
Intangible assets, amortization expenses	$ 9,907	¥ 68,115	¥ 143,602	¥ 183,964
Minimum
Finite-Lived Intangible Assets [Line Items]
Estimated useful life of intangible assets	1 year	1 year
Maximum
Finite-Lived Intangible Assets [Line Items]
Estimated useful life of intangible assets	20 years	20 years

Annual Estimated Amortization Expenses of Intangible Assets (Detail) - Dec. 31, 2018 ¥ in Thousands, $ in Thousands	USD ($)	CNY (¥)
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
2019	$ 8,227	¥ 56,567
2020	6,870	47,232
2021	6,545	45,005
2022	5,976	41,088
2023	4,120	28,322
Finite-Lived Intangible Assets, Net, Total	$ 31,738	¥ 218,214

Land Use Rights (Detail) ¥ in Thousands, $ in Thousands	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)
Goodwill and Intangible Assets Disclosure [Abstract]
Cost	$ 23,197	¥ 159,494	¥ 172,520
Accumulated amortization	(1,745)	(12,001)	(8,849)
Land use rights, net	$ 21,452	¥ 147,493	¥ 163,671

Carrying Value of Land Use Rights Pledged by Group to Secure Banking Borrowings (Detail) ¥ in Thousands, $ in Thousands	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)
Goodwill and Intangible Assets Disclosure [Abstract]
Land use rights	$ 2,386	¥ 16,403	¥ 16,818

Goodwill (Detail) ¥ in Thousands, $ in Thousands	12 Months Ended
Goodwill (Detail) ¥ in Thousands, $ in Thousands	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)	Dec. 31, 2016 CNY (¥)
Goodwill and Intangible Assets Disclosure [Abstract]
Beginning Balance	$ 143,921	¥ 989,530	¥ 1,755,970	¥ 1,755,970
Impairment		0	(766,440)	0
Ending Balance	$ 143,921	¥ 989,530	¥ 989,530	¥ 1,755,970

Goodwill - Additional Information (Detail) ¥ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 USD ($)	Dec. 31, 2017 CNY (¥)	Dec. 31, 2016 CNY (¥)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)	Dec. 31, 2015 CNY (¥)
Goodwill [Line Items]
Goodwill	$ 143,921		$ 143,921		¥ 1,755,970	¥ 989,530	¥ 989,530	¥ 1,755,970
Impairment losses of goodwill		¥ 0		¥ 766,440	0
Hosting and Related Services
Goodwill [Line Items]
Goodwill					989,530
Impairment losses of goodwill \| $	$ 0		$ 0
Managed Network Services [Member]
Goodwill [Line Items]
Goodwill					¥ 766,440

Long Term Investments (Detail) ¥ in Thousands, $ in Thousands	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)	Dec. 31, 2016 CNY (¥)
Long-term Investments [Abstract]
Equity investments without readily determinable fair values	$ 7,477	¥ 51,410	¥ 57,567
Equity method investments	71,322	490,376	450,822	¥ 234,863
Available-for-sale debt investments	369	2,537	2,537
Long term investments	$ 79,168	¥ 544,323	¥ 510,926

Long-Term Investments - Additional Information (Detail) $ in Thousands	1 Months Ended								12 Months Ended
	Mar. 31, 2018 USD ($)	Mar. 31, 2018 CNY (¥)	Jan. 31, 2018 USD ($)	Jan. 31, 2018 CNY (¥)	Sep. 30, 2017 CNY (¥)	Mar. 31, 2017 CNY (¥)	Dec. 31, 2013 CNY (¥)	Apr. 30, 2012 CNY (¥)	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)	Dec. 31, 2016 CNY (¥)	Dec. 31, 2018 CNY (¥)	Mar. 31, 2018 CNY (¥)	Jun. 30, 2016 CNY (¥)
Investment [Line Items]
Impairment of investment											¥ 20,258,000
Cost of investment											312,176,000	¥ 150,000,000	¥ 521,863,000
Equity method investment loss									$ (27,146)	¥ (186,642,000)	53,783,000	35,652,000
Equity method investment realized gain on disposal									2,401	16,509,000
Equity method investment									71,322		450,822,000	234,863,000	¥ 490,376,000
WiFire Group Inc. ("WiFire Group")
Investment [Line Items]
Equity interest, percentage					33.33%
Cost of investment											15,000,000
Percentage of ownership disposed					66.67%
Equity method investment											0
Equity method investment at fair value					¥ 6
Equity Investments Without Readily Determinable Fair Value
Investment [Line Items]
Equity investment without readily determinable fair values									3,877	26,653,000
Dividend income of non-marketable investments									59	406,000	1,821,000
Gain from disposal of non-marketable investments									$ 2,981	20,496,000	0
Impairment of investment										0	¥ 20,258,000	¥ 0
Yizhuang Venture Investment Fund
Investment [Line Items]
Equity interest, percentage									27.694%		27.694%	27.694%	27.694%
Investment in an equity investee, addition							¥ 50,500,000	¥ 50,500,000
Cost of investment											¥ 101,000,000	¥ 101,000,000	¥ 101,000,000
Equity method investment loss										(150,355,000)	90,888,000
Equity method investment									$ 18,425		277,036,000	186,148,000	126,681,000
Unis Tech
Investment [Line Items]
Equity interest, percentage															49.00%
Cost of investment											49,000,000	49,000,000			¥ 49,000,000
Equity method investment cash consideration	$ 7,127													¥ 49,000,000
Equity method investment loss	516	¥ 3,548,000								(3,548,000)	(12,676,000)
Equity method investment realized gain on disposal	$ 2,401	16,509,000								16,509,000
Equity method investment											36,039,000	¥ 48,175,000
Shihua DC Investment Holdings Limited
Investment [Line Items]
Equity interest, percentage						49.00%
Investment in an equity investee, addition						¥ 147,176,000			31,917	219,447,000
Cost of investment											147,176,000		366,623,000
Equity method investment loss										(24,229,000)	(9,429,000)
Equity method investment									48,428		¥ 137,747,000		332,965,000
Jingliang Inter Cloud
Investment [Line Items]
Equity interest, percentage			60.00%	60.00%
Investment in an equity investee, addition			$ 873	¥ 6,000,000
Cost of investment													6,000,000
Equity method investment loss										(34,000)
Equity method investment									868				5,966,000
Jingliang Century Cloud
Investment [Line Items]
Equity interest, percentage			40.00%	40.00%
Investment in an equity investee, addition			$ 582	¥ 4,000,000
Cost of investment													4,000,000
Equity method investment									582				4,000,000
Huaye Cloud
Investment [Line Items]
Equity interest, percentage	50.00%													50.00%
Investment in an equity investee, addition	$ 3,394	¥ 23,333,000
Cost of investment													23,333,000
Equity method investment loss										¥ (6,319,000)
Equity method investment									$ 2,474				¥ 17,014,000

Equity Method Investments (Detail) ¥ in Thousands, $ in Thousands	1 Months Ended		12 Months Ended
	Mar. 31, 2018 USD ($)	Mar. 31, 2018 CNY (¥)	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)	Dec. 31, 2016 CNY (¥)	Dec. 31, 2018 CNY (¥)	Jun. 30, 2016 CNY (¥)
Schedule of Equity Method Investments [Line Items]
Accumulated, share equity gain (loss)					¥ 138,646	¥ 84,863	¥ (47,996)
Investment in an equity investee, addition				¥ 209,687	162,176
Share equity gain, during period			$ (27,146)	(186,642)	53,783	35,652
Disposal gain			2,401	16,509
Cost investment					312,176	150,000	521,863
Accumulated, disposal gain							16,509
Investment in equity investee			71,322		450,822	234,863	490,376
Yizhuang Venture Investment Fund
Schedule of Equity Method Investments [Line Items]
Accumulated, share equity gain (loss)					176,036	85,148	25,681
Share equity gain, during period				(150,355)	90,888
Cost investment					101,000	101,000	101,000
Investment in equity investee			18,425		277,036	186,148	126,681
Unis Tech
Schedule of Equity Method Investments [Line Items]
Accumulated, share equity gain (loss)					(12,961)	(285)	(16,509)
Investment in an equity investee, addition				(49,000)
Share equity gain, during period	$ 516	¥ 3,548		(3,548)	(12,676)
Disposal gain	$ 2,401	¥ 16,509		16,509
Cost investment					49,000	49,000		¥ 49,000
Accumulated, disposal gain							16,509
Investment in equity investee					36,039	¥ 48,175
Shihua DC Investment Holdings Limited
Schedule of Equity Method Investments [Line Items]
Accumulated, share equity gain (loss)					(9,429)		(33,658)
Investment in an equity investee, addition				219,447	147,176
Share equity gain, during period				(24,229)	(9,429)
Cost investment					147,176		366,623
Investment in equity investee			48,428		137,747		332,965
WiFire Group Inc. ("WiFire Group")
Schedule of Equity Method Investments [Line Items]
Accumulated, share equity gain (loss)					(15,000)		(15,000)
Investment in an equity investee, addition					15,000
Share equity gain, during period					(15,000)
Cost investment					¥ 15,000		15,000
Jingliang Inter Cloud
Schedule of Equity Method Investments [Line Items]
Accumulated, share equity gain (loss)							(34)
Investment in an equity investee, addition				6,000
Share equity gain, during period				(34)
Cost investment							6,000
Investment in equity investee			868				5,966
Jingliang Century Cloud
Schedule of Equity Method Investments [Line Items]
Investment in an equity investee, addition				4,000
Cost investment							4,000
Investment in equity investee			582				4,000
Huaye Cloud
Schedule of Equity Method Investments [Line Items]
Accumulated, share equity gain (loss)							(6,319)
Investment in an equity investee, addition				23,333
Share equity gain, during period				(6,319)
Cost investment							23,333
Investment in equity investee			2,474				17,014
ZJK Energy
Schedule of Equity Method Investments [Line Items]
Accumulated, share equity gain (loss)							(2,157)
Investment in an equity investee, addition				5,907
Share equity gain, during period				¥ (2,157)
Cost investment							5,907
Investment in equity investee			$ 545				¥ 3,750

Summary of Bank Borrowings (Detail) ¥ in Thousands, $ in Thousands	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)
Debt Disclosure [Abstract]
Short-term bank borrowings	$ 7,272	¥ 50,000	¥ 50,000
Long-term bank borrowings, current portion	10,950	75,284	70,289
Debt, Current, Total	18,222	125,284	120,289
Long-term bank borrowings, non-current portion	16,290	112,000	187,638
Total bank borrowings	$ 34,512	¥ 237,284	¥ 307,927

Bank Borrowings - Additional Information (Detail) ¥ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)
Schedule Of Short And Long Term Debt [Line Items]
Short-term bank borrowings, weighted Average Interest rate	4.05%	4.05%	4.04%
Short-term bank borrowings, term	1 year
Unused loan facilities (in RMB) or (in dollars)	$ 3,109	¥ 21,375	¥ 140,940
Long Term Bank Borrowings
Schedule Of Short And Long Term Debt [Line Items]
Long-term bank borrowings, weighted average interest rate	5.31%	5.31%	5.50%

Secured Bank Borrowings (Detail) ¥ in Thousands, $ in Thousands	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)
Debt Instrument [Line Items]
Short-term borrowings	$ 7,272	¥ 50,000	¥ 50,000
Long-term bank borrowings (including current portion)		187,284	257,927
Unsecured Borrowing
Debt Instrument [Line Items]
Long-term bank borrowings (including current portion)		49,284	99,927
Secured by a Subsidiary's Fixed Assets and Land Use Right \| Long-term bank borrowings, (including current portion) 1
Debt Instrument [Line Items]
Long-term bank borrowings (including current portion)		138,000	158,000
Secured by restricted cash \| Short-term bank borrowings 1
Debt Instrument [Line Items]
Short-term borrowings		¥ 50,000	¥ 50,000

Secured Bank Borrowings (Parenthetical) (Detail) ¥ in Thousands, $ in Thousands	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)
Debt Instrument [Line Items]
Assets pledged as collateral	$ 44,069	¥ 302,999
Long-term bank borrowings, (including current portion) 1 \| Fixed assets
Debt Instrument [Line Items]
Assets pledged as collateral	41,683	286,596	¥ 344,932
Long-term bank borrowings, (including current portion) 1 \| Land Use Rights [Member]
Debt Instrument [Line Items]
Assets pledged as collateral	2,386	16,403	16,818
Short-term bank borrowings 1
Debt Instrument [Line Items]
Restricted cash	$ 8,842	¥ 60,796	¥ 50,809

Components of Accrued Expenses and Other Payables (Detail) ¥ in Thousands, $ in Thousands	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)
Payables and Accruals [Abstract]
Payroll and welfare payables	$ 32,618	¥ 224,265	¥ 197,171
Value-added tax and other taxes payable	2,463	16,931	16,951
Payables for office supplies and utilities	3,159	21,719	29,488
Payables for the purchase of property and equipment	30,181	207,512	185,594
Payables for the purchase of intangible assets	666	4,576	3,706
Accrued service fees	6,053	41,618	52,090
Interest payables	7,909	54,376	57,359
Liability classified RSU	723	4,970	11,865
Payables for acquisitions	6,946	47,755	47,755
Payables for litigation settlement			9,801
Others	5,176	35,598	45,353
Accrued expenses and other payables	$ 95,894	¥ 659,320	¥ 657,133

Future Minimum Lease Payments Under Non Cancellable Capital Lease Arrangements (Detail) - Dec. 31, 2018 ¥ in Thousands, $ in Thousands	USD ($)	CNY (¥)
Capital Lease Obligations [Abstract]
2019	$ 44,464	¥ 305,710
2020	31,638	217,525
2021	46,161	317,382
2022	14,106	96,990
2023 and thereafter	83,767	575,941
Total minimum lease payments	220,136	1,513,548
Less: amount representing interest	(76,774)	(527,860)
Present value of remaining minimum lease payments	$ 143,362	¥ 985,688

Capital Leases - Additional Information (Detail)	Dec. 31, 2018	Dec. 31, 2017
Capital Leases
Schedule of Capital Lease Obligations [Line Items]
Weighted average interest rate	10.37%	9.93%

Bonds Payable - Additional Information (Detail) ¥ in Thousands, $ in Thousands			12 Months Ended
	Sep. 29, 2017 USD ($)	Aug. 17, 2017 CNY (¥)	Dec. 31, 2017 CNY (¥)	Aug. 17, 2017 USD ($)
Debt Instrument [Line Items]
Proceeds from issuance of bonds, net			¥ 1,936,154
Bonds 7% Due 2020
Debt Instrument [Line Items]
Debt instrument, face amount \| $	$ 100,000			$ 200,000
Debt instrument, stated rate	7.00%			7.00%
Debt instrument, maturity date	Aug. 17, 2020	Aug. 17, 2020
Debt instrument, frequency of periodic payment		Payable semi-annually in arrears on August 17 and February 17 in each year
Debt instrument, premium price	1.0004
Debt instrument, effective yield	6.98%
Proceeds from issuance of bonds, net		¥ 1,926,419

Repayments of Principal Amounts of Long-Term Borrowings, Including Bonds Payable, Bank and Other Borrowings (Detail) - Dec. 31, 2018 ¥ in Thousands, $ in Thousands	USD ($)	CNY (¥)
Debt Disclosure [Abstract]
2019	$ 18,222	¥ 125,284
2020	304,190	2,091,460
2021	5,672	39,000
2022	5,890	40,500
2023 thereafter	$ 0	¥ 0

Deferred Government Grants - Additional Information (Detail) ¥ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)	Dec. 31, 2016 CNY (¥)
Components of Other Income (Expense) [Line Items]
Government grants received	$ 494,660	¥ 3,401,037	¥ 3,392,705	¥ 3,641,774
Grant
Components of Other Income (Expense) [Line Items]
Government grants received	$ 73	¥ 500	¥ 2,877	¥ 0

Movements of Deferred Government Grants (Detail) ¥ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)	Dec. 31, 2016 CNY (¥)
Components of Other Income (Expense) [Line Items]
Additions	$ 494,660	¥ 3,401,037	¥ 3,392,705	¥ 3,641,774
Grant
Components of Other Income (Expense) [Line Items]
Balance at beginning of the year	3,263	22,435	30,993	37,620
Additions	73	500	2,877	0
Decrease due to disposal of subsidiaries			(3,573)
Recognized as a reduction of depreciation expense	(1,039)	(7,143)	(7,862)	(6,627)
Balance at end of the year	$ 2,297	¥ 15,792	¥ 22,435	¥ 30,993

Treasury Stock - Additional Information (Detail) - shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Schedule of Capitalization, Equity [Line Items]
Share Repurchase Plan, shares repurchased (in shares)	0	3,448,482	815,525
American Depository Shares
Schedule of Capitalization, Equity [Line Items]
Share Repurchase Plan, shares repurchased (in shares)	0	3,448,482	815,525
Business acquisition, shares issued	0	0	223,161

Changes in Accumulated Other Comprehensive (Loss) Income by Component, Net of Tax (Detail) ¥ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)	Dec. 31, 2016 CNY (¥)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		¥ 5,201,004	¥ 6,151,017	¥ 4,034,375
Other comprehensive income (loss)	$ 12,894	88,652	(120,963)	142,526
Ending Balance	780,042	5,363,184	5,201,004	6,151,017
Accumulated Translation Adjustment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		(2,673)	118,290	(24,236)
Other comprehensive income (loss)		88,652	(120,963)	142,526
Ending Balance	$ 12,505	¥ 85,979	¥ (2,673)	¥ 118,290

Mainland China Employee Contribution Plan - Additional Information (Detail) ¥ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)	Dec. 31, 2016 CNY (¥)
PRC
Multiemployer Plans [Line Items]
Total expense for defined contribution plan	$ 17,797	¥ 122,362	¥ 134,053	¥ 130,630

Share Based Compensation - Additional Information (Detail) $ / shares in Units, ¥ in Thousands			12 Months Ended
	May 29, 2014 shares	Jul. 16, 2010 shares	Dec. 31, 2018 USD ($) $ / shares shares	Dec. 31, 2018 CNY (¥) shares	Dec. 31, 2017 USD ($) $ / shares shares	Dec. 31, 2017 CNY (¥) shares	Dec. 31, 2016 USD ($) $ / shares shares	Dec. 31, 2016 CNY (¥) shares	Dec. 31, 2018 CNY (¥) shares	Oct. 30, 2015 shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share based compensation, fair value of shares exercised during the period \| ¥				¥ 435		¥ 926		¥ 3,391
Aggregate intrinsic value of options exercise \| $			$ 248,000		$ 306,000		$ 1,906,000
Share based compensation expense			$ 8,659,000	59,538		47,129		118,729
Dermot Entities
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share based compensation expense \| ¥				¥ 0		¥ 5,752		¥ 10,871
Performance Based Awards \| One or Four-Year Period
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share based compensation, RSUs granted			487,368	487,368	611,111	611,111	1,059,668	1,059,668
Performance Based Awards \| Option One
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance review period			1 year	1 year
Performance Based Awards \| Option Two
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance review period			4 years	4 years
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share based compensation, RSUs granted			3,222,650	3,222,650
Aggregate fair value, unvested			$ 27,807,000						¥ 191,187
Weighted-average grant-date fair value \| $ / shares			$ 6.39		$ 6.31		$ 8.85
Total fair value vested \| $			$ 9,422,000		$ 18,238,000		$ 14,849,000
Unrecognized share-based compensation cost			$ 12,262,000						¥ 84,307
Unrecognized compensation costs, weighted-average recognition period			3 years 7 months 6 days	3 years 7 months 6 days
Minimum Performance Target
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share based compensation, RSUs granted			2,188,226	2,188,226
Market Based Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share based compensation, RSUs granted			547,056	547,056
2014 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share based compensation, option expiry period	10 years
2014 Plan \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share based compensation, maximum aggregate number of ordinary shares to be issued	20,461,380									39,606,817
Share based compensation, option vesting period	4 years
Share based compensation arrangement by share based payment award maximum annual plan percentage increase to number of shares available for grant	15.00%
2014 Plan \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share based compensation, option vesting period	3 years
2010 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share based compensation, option expiry period		10 years
Share based compensation, option outstanding			1,479,214		1,699,186	1,699,186			1,479,214
Share based compensation, aggregate intrinsic value			$ 1,370,000						¥ 9,419
Share based compensation, fair value of option outstanding at grant date			$ 2,126,000						¥ 14,617
Share based compensation, weighted average grant-date fair value of option \| $ / shares			$ 0		$ 0		$ 2
Share based compensation, fair value of shares exercised during the period \| $			$ 239,000		$ 404,000		$ 2,147,000
2010 Plan \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share based compensation, maximum aggregate number of ordinary shares to be issued		39,272,595
Share based compensation, option vesting period		4 years
2010 Plan \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share based compensation, option vesting period		3 years

Summary of Employee Share Option Activity (Detail) - 2010 Plan $ / shares in Units, ¥ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($) $ / shares shares	Dec. 31, 2017 $ / shares shares	Dec. 31, 2018 CNY (¥) shares
Number of options
Outstanding, beginning balance \| shares	1,699,186
Exercised (in shares) \| shares	(219,972)
Outstanding, ending balance \| shares	1,479,214	1,699,186
Vested and expected to vest at December 31, 2018 \| shares	1,479,214		1,479,214
Exercisable as of December 31, 2018 \| shares	1,479,214		1,479,214
Weighted average exercise price
Outstanding, beginning balance \| $ / shares	$ 0.49
Exercised \| $ / shares	0.31
Outstanding, ending balance \| $ / shares	0.51	$ 0.49
Vested and expected to vest at December 31, 2018 \| $ / shares	0.51
Exercisable as of December 31, 2018 \| $ / shares	$ 0.51
Weighted average remaining contractual term
Outstanding, December 31, 2018	2 years 2 months 12 days	3 years 6 months
Vested and expected to vest at December 31, 2018	2 years 2 months 12 days
Exercisable as of December 31, 2018	2 years 2 months 12 days
Aggregate intrinsic value
Outstanding, December 31, 2018	$ 1,370		¥ 9,419
Vested and expected to vest at December 31, 2018 \| $	1,370
Exercisable as of December 31, 2018 \| $	$ 1,370

Restricted Stock Units Activity (Detail) - Restricted Stock Units (RSUs) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Number of RSUs
Unvested, beginning balance	1,516,898
Granted	3,222,650
Vested	(852,593)
Forfeited	(668,503)
Unvested, ending balance	3,218,452	1,516,898
Weighted-average grant date fair value
Unvested, beginning balance (in dollars per share)	$ 11.76
Granted (in dollars per share)	6.39
Vested (in dollars per share)	11.05
Forfeited (in dollars per share)	14.95
Unvested, ending balance (in dollars per share)	$ 6.66	$ 11.76
Weighted-average remaining contractual terms (Years)
Unvested, December 31, 2018	9 years	7 years 10 months 24 days
Aggregated intrinsic value
Unvested, December 31, 2018 (in dollars)	$ 27,807

Total Compensation Expense Recognized Relating to Options Granted to Employees (Detail) ¥ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)	Dec. 31, 2016 CNY (¥)
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share based compensation expense	$ 8,659	¥ 59,538	¥ 47,129	¥ 118,729
Cost of Revenues
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share based compensation expense	388	2,668	(277)	(4,110)
Selling and Marketing Expense
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share based compensation expense	311	2,139	(681)	2,490
General and Administrative Expense
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share based compensation expense	7,759	53,346	47,945	123,273
Research and Development Expense
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share based compensation expense	$ 201	¥ 1,385	¥ 142	¥ (2,924)

Taxation - Additional Information (Detail) ¥ in Thousands, $ in Thousands		1 Months Ended			12 Months Ended					24 Months Ended			132 Months Ended
	Jan. 01, 2008	Nov. 30, 2016	Oct. 31, 2015	Apr. 30, 2011	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)	Dec. 31, 2016 CNY (¥)	Dec. 31, 2015	Dec. 31, 2017 CNY (¥)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)
Income Taxes [Line Items]
Unified enterprise income tax rate	25.00%
Statutory income tax rate					25.00%	25.00%	25.00%	25.00%
Undistributed earnings from its PRC subsidiaries					$ 163,405								$ 163,405	¥ 1,123,491
Unrecognized tax benefits					$ 971		¥ 16,511			¥ 16,511			$ 971	6,677
Unrecognized tax benefits impact in the effective rate														1,896
Shanghai Blue Cloud Technology Co., Ltd. ("SH Blue Cloud")
Income Taxes [Line Items]
Preferential tax rate			15.00%		15.00%	15.00%	15.00%	15.00%
Preferential tax rate, additional term			3 years
Shenzhen Diyixian Telecommunication Co., Ltd. ("SZ DYX")
Income Taxes [Line Items]
Preferential tax rate		15.00%			15.00%	15.00%	15.00%	15.00%
Preferential tax rate, additional term		3 years
Beijing 21Vianet Broad Band Data Center Co., Ltd. ("21Vianet Beijing")
Income Taxes [Line Items]
Preferential tax rate					15.00%	15.00%	15.00%	15.00%					15.00%
21Vianet (Xi'an) Information Outsourcing Industry Park Services Co., Ltd. ("Xi'an Sub")
Income Taxes [Line Items]
Preferential tax rate				15.00%	15.00%	15.00%	25.00%	25.00%
Beijing iJoy Information Technology Co., Ltd. ("BJ iJoy")
Income Taxes [Line Items]
Unified enterprise income tax rate					25.00%	25.00%
Tax holiday, exemption rate								50.00%	50.00%	50.00%	100.00%	100.00%
Tax holiday reduction period									3 years		2 years
TAIWAN \| DYX Taiwan
Income Taxes [Line Items]
Income tax rate					17.00%	17.00%	17.00%	17.00%
PRC
Income Taxes [Line Items]
Income tax rate on PRC tax resident enterprises					25.00%	25.00%
Net tax operating losses from PRC subsidiaries (in RMB)					$ 66,106								$ 66,106	454,513
Interest expenses (in RMB)					(402)	¥ (2,761)	¥ 674	¥ 2,779
Accumulated interest expenses (in RMB)					$ 315		¥ 4,929			¥ 4,929			$ 315	¥ 2,168
PRC \| Minimum
Income Taxes [Line Items]
Net tax operating losses expiration year					2019	2019
PRC \| Maximum
Income Taxes [Line Items]
Net tax operating losses expiration year					2028	2028
HONG KONG \| 21Vianet Hong Kong Entities
Income Taxes [Line Items]
Withholding tax amount						¥ 0
Income tax rate					16.50%	16.50%	16.50%	16.50%
Non-PRC
Income Taxes [Line Items]
Withholding tax percent					10.00%	10.00%
British Virgin Islands \| 21Vianet Hong Kong Entities
Income Taxes [Line Items]
Withholding tax amount						¥ 0

Profit or Loss Before Income Taxes (Detail) ¥ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)	Dec. 31, 2016 CNY (¥)
Schedule of Income Before Income Tax [Line Items]
Loss before income taxes	$ (23,611)	¥ (162,325)	¥ (1,007,814)	¥ (943,082)
Non-PRC
Schedule of Income Before Income Tax [Line Items]
Loss before income taxes	(31,136)	(214,063)	(286,388)	(155,364)
PRC
Schedule of Income Before Income Tax [Line Items]
Loss before income taxes	$ 7,525	¥ 51,738	¥ (721,426)	¥ (787,718)

Income Tax Benefits (Expense) (Detail) ¥ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)	Dec. 31, 2016 CNY (¥)
Income Tax Disclosure [Abstract]
Current	$ (6,426)	¥ (44,187)	¥ (37,856)	¥ (54,772)
Deferred	2,876	19,776	128,026	65,932
Income tax benefits (expenses)	$ (3,550)	¥ (24,411)	¥ 90,170	¥ 11,160

Reconciliation Tax Computed Applying Statutory Income Tax Rate (Detail) ¥ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)	Dec. 31, 2016 CNY (¥)
Income Tax Disclosure [Abstract]
Loss before income taxes	$ (23,611)	¥ (162,325)	¥ (1,007,814)	¥ (943,082)
Income tax benefits computed at applicable tax rates (25%)	5,902	40,581	251,954	235,770
Non-deductible expenses	(412)	(2,834)	(5,468)	(16,610)
Research and development expenses	3,768	25,906	11,895	7,766
Effect of tax holidays				1,691
Preferential rate	1,702	11,701	(90,076)	(11,060)
Current and deferred tax rate differences	5,517	37,934	33,366	(1,521)
International rate differences	(9,239)	(63,525)	59,029	(51,392)
Tax exempted income				9,878
Unrecognized tax benefits	214	1,472	(6,259)	(14,525)
Deferred tax expense			2,851	1,516
Change in valuation allowance	(11,591)	(79,694)	(174,388)	(158,724)
Prior year provision to return true up	589	4,048	7,266	8,371
Income tax benefits (expenses)	$ (3,550)	¥ (24,411)	¥ 90,170	¥ 11,160

Reconciliation Tax Computed Applying Statutory Income Tax Rate (Parenthetical) (Detail)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Statutory income tax rate	25.00%	25.00%	25.00%

Tax Holiday Benefit Per Basic and Diluted Earnings per share (Detail)	12 Months Ended
	Dec. 31, 2016 ¥ / shares
Income Tax Disclosure [Abstract]
Basic	¥ 0.003
Diluted	¥ 0.003

Significant Components of Deferred Taxes (Detail) ¥ in Thousands, $ in Thousands	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)
Non-current
Allowance for doubtful debt	$ 5,670	¥ 38,993	¥ 33,978
Accrued expenses	3,766	25,894	7,409
Tax losses	22,278	153,171	135,433
Property and equipment	2,226	15,299	7,642
Intangible assets	323	2,221	2,976
Capital lease	7,415	50,980	22,006
Deferred government grants	387	2,662	3,728
Disposal loss on long-term investments	7,128	49,007	57,697
Loss picked up on equity method investments	855	5,878	6,919
Valuation allowance	(26,858)	(184,664)	(104,970)
Total deferred tax assets	23,190	159,441	172,818
Non-current
Intangible assets	13,022	89,536	97,915
Property and equipment	7,053	48,496	49,676
Capitalized interest expenses	2,303	15,837	16,185
Gain picked up from equity method investments	561	3,851	27,097
Total deferred tax liabilities	$ 22,939	¥ 157,720	¥ 190,873

Unrecognized Tax Benefits (Detail) ¥ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)
Income Tax Disclosure [Abstract]
Balance at beginning of year	$ 1,685	¥ 11,582	¥ 23,220
Reversal based on tax positions related to prior years	(1,319)	(9,070)	(8,880)
Additions based on tax positions related to the current year	290	1,997	4,825
Decrease due to disposal of subsidiaries			(7,583)
Balance at end of year	$ 656	¥ 4,509	¥ 11,582

Related Party Transactions (Detail) ¥ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)	Dec. 31, 2016 CNY (¥)	Dec. 31, 2018 CNY (¥)
Related Party Transaction [Line Items]
Related party transaction, loans from	$ 7,611		¥ 55,675		¥ 52,328
Xiaomi Communication Technology Limited and Beijing Xiaomi Mobile Software Limited \| Service Revenue
Related Party Transaction [Line Items]
Revenue from related party transactions	54,408	¥ 374,085	220,110	¥ 125,147
Beijing Kingsoft Cloud Network Technology Limited
Related Party Transaction [Line Items]
Related party transaction, loans from	89		2,070		609
Beijing Kingsoft Cloud Network Technology Limited \| Service Revenue
Related Party Transaction [Line Items]
Revenue from related party transactions	914	6,281	8,046	19,471
Beijing Kingsoft Cloud Network Technology Limited \| Service Expense [Member]
Related Party Transaction [Line Items]
Related party transaction expense	1,920	13,204	7,775	1,045
Beijing Bozhiruihai Network Technology Co., Ltd. ("BZRH") \| Service Expense [Member]
Related Party Transaction [Line Items]
Related party transaction expense	617	4,239
Beijing Tuspark Harmonious Investment Development Co Ltd
Related Party Transaction [Line Items]
Related party transaction, loans from	2,014				13,850
Related party transaction, Lease deposit paid	1,669	11,472
Beijing Cheetah Mobile Technology Limited \| Service Revenue
Related Party Transaction [Line Items]
Revenue from related party transactions	302	2,079	5,128	9,478
Other Related Party Transactions
Related Party Transaction [Line Items]
Related party transaction, loans from	266		1,561		1,826
Other Related Party Transactions \| Service Revenue
Related Party Transaction [Line Items]
Revenue from related party transactions	653	4,493	3,314	2,413
Other Related Party Transactions \| Service Expense [Member]
Related Party Transaction [Line Items]
Related party transaction expense	963	6,396	2,632	9,178
Dyxnet Corporate Service Limited \| Service Expense [Member]
Related Party Transaction [Line Items]
Related party transaction expense	762	5,238	6,424	10,883
Beijing Chengyishidai Network Technology Company Limited
Related Party Transaction [Line Items]
Related party transaction, loans from	1,041		3,618		7,158
Beijing Chengyishidai Network Technology Company Limited \| Service Expense [Member]
Related Party Transaction [Line Items]
Related party transaction expense	2,715	18,667	2,979
Beijing Fastweb Network Technology Co Ltd Bjfastweb
Related Party Transaction [Line Items]
Related party transaction, loans to			20,000
Related party transaction, interest income from loan	102	700	210
Beijing Fastweb Network Technology Co Ltd Bjfastweb \| Equipment and Property
Related Party Transaction [Line Items]
Related party transaction, sales of equipment and property			1,021
WNT Technology Limited \| Equipment and Property
Related Party Transaction [Line Items]
Related party transaction, purchase of equipment and property			2,629
Dyxnet Internet Center Limited \| Equipment and Property
Related Party Transaction [Line Items]
Related party transaction, purchase of equipment and property			1,234	3,079
CD Guotao
Related Party Transaction [Line Items]
Related party transaction, loans from				¥ 3,483
WiFire (Beijing) Technology Co., Ltd. \| Service Revenue
Related Party Transaction [Line Items]
Revenue from related party transactions	2,398	16,490	9,726
WiFire (Beijing) Technology Co., Ltd. \| Service Expense [Member]
Related Party Transaction [Line Items]
Related party transaction expense	591	4,066	¥ 1,616
Beijing Taiji Data Tech Co Ltd
Related Party Transaction [Line Items]
Related party transaction, loans from	978				6,724
Beijing Taiji Data Tech Co Ltd \| Service Revenue
Related Party Transaction [Line Items]
Revenue from related party transactions	1,990	13,681
Beijing Taiji Data Tech Co Ltd \| Service Expense [Member]
Related Party Transaction [Line Items]
Related party transaction expense	1,032	7,095
UNISVNET Technology Co Ltd \| Service Revenue
Related Party Transaction [Line Items]
Revenue from related party transactions	147	1,011
Ziguang Financial Leasing Co Ltd
Related Party Transaction [Line Items]
Related party transaction, loans from	1,300				¥ 8,938
Related party transaction, Lease deposit paid	297	2,042
Related party transaction, Lease payment paid	712	4,897
Jingliang Interconnected Cloud Technology Co Ltd \| Service Expense [Member]
Related Party Transaction [Line Items]
Related party transaction expense	$ 506	¥ 3,477

Related Party Balances (Detail) ¥ in Thousands, $ in Thousands	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)
Amounts due from related parties current:
Amounts due from related parties current	$ 18,245	¥ 125,446	¥ 114,256
Amounts due from related parties non-current:
Amounts due from related parties non current	5,007	34,424	20,210
Amounts due to related parties current:
Amount due to a related party	7,611	52,328	55,675
Amounts due from related parties non-current:
Amounts due to related parties non current	73,373	504,478
Xiaomi Communication Technology Limited and Beijing Xiaomi Mobile Software Limited
Amounts due from related parties current:
Amounts due from related parties current	5,986	41,159	39,016
Seller of iJoy
Amounts due from related parties current:
Amounts due from related parties current			26,137
Amounts due to related parties current:
Amount due to a related party			39,068
WiFire (Beijing) Technology Co., Ltd.
Amounts due from related parties current:
Amounts due from related parties current	5,320	36,578	15,321
Shanghai Fawei Technology Co., Ltd. (SH Fawei)
Amounts due from related parties current:
Amounts due from related parties current	1,999	13,742	10,332
Shanghai Shibei Hi-Tech Co., Ltd.
Amounts due from related parties current:
Amounts due from related parties current	1,425	9,800	9,800
Beijing Kingsoft Cloud Network Technology Limited
Amounts due from related parties current:
Amounts due from related parties current	143	982	5,663
Amounts due to related parties current:
Amount due to a related party	89	609	2,070
Wuhan Fastweb Cloud Computing Company Limited
Amounts due from related parties current:
Amounts due from related parties current	746	5,131	4,600
Beijing Taiji Data Tech Co Ltd
Amounts due from related parties current:
Amounts due from related parties current	1,970	13,542
Amounts due to related parties current:
Amount due to a related party	978	6,724
UNISVNET Technology Co Ltd
Amounts due from related parties current:
Amounts due from related parties current	156	1,072
Other Related Party Transactions
Amounts due from related parties current:
Amounts due from related parties current	500	3,440	3,387
Amounts due to related parties current:
Amount due to a related party	266	1,826	1,561
Beijing Fastweb Network Technology Co Ltd Bjfastweb
Amounts due from related parties non-current:
Amounts due from related parties non current	3,041	20,910	20,210
Beijing Bozhi Ruihai Network Technology Co Ltd
Amounts due to related parties current:
Amount due to a related party	740	5,088	9,358
Beijing Chengyishidai Network Technology Company Limited
Amounts due to related parties current:
Amount due to a related party	1,041	7,158	¥ 3,618
Ziguang Financial Leasing Co Ltd
Amounts due from related parties non-current:
Amounts due from related parties non current	297	2,042
Amounts due to related parties current:
Amount due to a related party	1,300	8,938
Amounts due from related parties non-current:
Amounts due to related parties non current	1,822	12,527
Beijing Tuspark Harmonious Investment Development Co Ltd
Amounts due from related parties non-current:
Amounts due from related parties non current	1,669	11,472
Amounts due to related parties current:
Amount due to a related party	2,014	13,850
Amounts due from related parties non-current:
Amounts due to related parties non current	64,522	443,622
Wi Fire Shanghai Network Technology Co Ltd
Amounts due to related parties current:
Amount due to a related party	1,183	8,135
Shihua DC Investment Holdings Limited
Amounts due from related parties non-current:
Amounts due to related parties non current	$ 7,029	¥ 48,329

Segment Reporting - Additional Information (Detail)	12 Months Ended
Segment Reporting - Additional Information (Detail)	Dec. 31, 2016 Segment
Segment Reporting [Abstract]
Number of segments	2

Summary of Segment Results (Detail) ¥ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 USD ($)	Dec. 31, 2017 CNY (¥)	Dec. 31, 2016 CNY (¥)
Segment Reporting Information [Line Items]
Revenues	$ 494,660	¥ 3,401,037		¥ 3,392,705	¥ 3,641,774
Cost	357,235	2,456,166		2,634,295	2,929,638
Gross profit (loss)	137,425	944,871		758,410	712,136
Operating income (expenses)
Revenues	494,660	3,401,037		3,392,705	3,641,774
Operating income	731	5,027		5,439	6,783
Group consolidated revenue	494,660	3,401,037		3,392,705	3,641,774
Cost	357,235	2,456,166		2,634,295	2,929,638
Gross profit (loss)	137,425	944,871		758,410	712,136
Sales and marketing expenses	25,042	172,176		256,682	352,926
Research and development expenses	13,397	92,109		149,143	149,337
General and administrative expenses	67,288	462,637		519,950	639,648
(Allowance) reversal for doubtful debt	(87)	(598)		37,427	117,564
Changes in the fair value of contingent purchase consideration payables	(2,022)	(13,905)		937	(93,307)
Impairment of goodwill		0		766,440	0
Impairment of long-lived assets				401,808	392,947
Operating profit (loss)	34,538	237,479		(1,368,538)	(840,196)
Hosting and Related Services
Operating income (expenses)
Impairment of goodwill \| $	0		$ 0
Operating Segments \| Hosting and Related Services
Segment Reporting Information [Line Items]
Revenues	494,660	3,401,037		2,975,178	2,668,655
Cost	(357,235)	(2,456,166)		(2,130,279)	(1,936,658)
Gross profit (loss)	137,425	944,871		844,899	731,997
Operating income (expenses)
Revenues	494,660	3,401,037		2,975,178	2,668,655
Operating income	731	5,027		5,439	6,783
Cost	(357,235)	(2,456,166)		(2,130,279)	(1,936,658)
Gross profit (loss)	137,425	944,871		844,899	731,997
Sales and marketing expenses	(25,042)	(172,176)		(171,761)	(144,335)
Research and development expenses	(13,397)	(92,109)		(97,597)	(87,227)
General and administrative expenses	(67,288)	(462,637)		(417,154)	(404,181)
(Allowance) reversal for doubtful debt	87	598		(6,257)	(78,330)
Changes in the fair value of contingent purchase consideration payables	2,022	13,905		(937)	19,394
Operating profit (loss)	$ 34,538	¥ 237,479		156,632	44,101
Operating Segments \| Managed Network Services
Segment Reporting Information [Line Items]
Revenues				417,527	973,119
Cost				(504,016)	(992,980)
Gross profit (loss)				(86,489)	(19,861)
Operating income (expenses)
Revenues				417,527	973,119
Cost				(504,016)	(992,980)
Gross profit (loss)				(86,489)	(19,861)
Sales and marketing expenses				(84,921)	(208,591)
Research and development expenses				(51,546)	(62,110)
General and administrative expenses				(102,796)	(235,467)
(Allowance) reversal for doubtful debt				(31,170)	(39,234)
Changes in the fair value of contingent purchase consideration payables					73,913
Impairment of goodwill				(766,440)
Impairment of long-lived assets				(401,808)	(392,947)
Operating profit (loss)				¥ (1,525,170)	¥ (884,297)

Restricted Net Asset - Additional Information (Detail) ¥ in Thousands, $ in Thousands	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)
Statutory Accounting Practices [Line Items]
Statutory reserves	$ 6,167	¥ 42,403	¥ 38,736
Restricted net asset, PRC generally accepted accounting principles (in RMB) or (in dollars)	761,341	5,234,597
PRC
Statutory Accounting Practices [Line Items]
Statutory reserves	$ 6,167	¥ 42,403	¥ 38,736
PRC \| Minimum
Statutory Accounting Practices [Line Items]
Minimum required Percentage of annual after-tax profit to the general statutory reserve	10.00%	10.00%
PRC \| Maximum
Statutory Accounting Practices [Line Items]
Maximum requirement of each of the Entity's PRC Subsidiaries' after-tax profits to be allocated to a general reserve fund as a percentage of each Subsidiaries' registered capital	50.00%	50.00%

Basic and Diluted Loss Per Share (Detail) ¥ / shares in Units, $ / shares in Units, ¥ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($) $ / shares shares	Dec. 31, 2018 CNY (¥) ¥ / shares shares	Dec. 31, 2017 CNY (¥) ¥ / shares shares	Dec. 31, 2016 CNY (¥) ¥ / shares shares
Numerator:
Net loss	$ (27,161)	¥ (186,736)	¥ (917,644)	¥ (931,922)
Net loss (profit) attributable to noncontrolling interest and redeemable noncontrolling interest	(2,666)	(18,329)	144,914	298,324
Net loss attributable to ordinary shareholders	(29,827)	(205,065)	(772,730)	(633,598)
Plus increase in accretion of redeemable noncontrolling interests \| ¥			(141,896)	(210,484)
Adjusted net loss attributable to ordinary shareholders	$ (29,827)	¥ (205,065)	¥ (914,626)	¥ (844,082)
Denominator:
Weighted-average number of shares outstanding - basic (in shares)	674,732,130	674,732,130	672,836,226	617,169,833
Weighted-average number of shares outstanding - diluted (in shares)	674,732,130	674,732,130	672,836,226	617,169,833
Loss per share-Basic:
Net loss \| (per share)	$ (0.04)	¥ (0.30)	¥ (1.36)	¥ (1.37)
Basic (in per share) \| (per share)	(0.04)	(0.30)	(1.36)	(1.37)
Loss per share-Diluted:
Net loss \| (per share)	(0.04)	(0.30)	(1.36)	(1.37)
Diluted (in per share) \| (per share)	$ (0.04)	¥ (0.30)	¥ (1.36)	¥ (1.37)

Loss Per Share - Additional Information (Detail) - shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Earnings Per Share [Abstract]
Shares issued to depository bank (in shares)	9,000,000	4,500,000

Share Capital - Additional Information (Detail)	12 Months Ended
Share Capital - Additional Information (Detail)	Dec. 31, 2018 shares	Dec. 31, 2017 shares	Dec. 31, 2016 shares	Oct. 31, 2010 shares Vote
Class A Ordinary Shares
Class of Stock [Line Items]
Entitled vote per ordinary share \| Vote				1
Issuance of new shares for share option exercise and restricted share units vested \| shares	3,070,500	3,119,052	3,261,456
Class B Ordinary Shares
Class of Stock [Line Items]
Entitled vote per ordinary share \| Vote				10
Conversion ratio, Class B ordinary share into Class A Ordinary Share \| shares				1

Redeemable Noncontrolling Interests - Additional Information (Detail) - Aipu Group $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017 USD ($)	Dec. 31, 2016	Dec. 31, 2015 Tranche	May 31, 2014
Redeemable Noncontrolling Interest [Line Items]
Business acquisition, equity interests acquired					50.00%
Number of tranches \| Tranche				3
Business acquisition, equity interests held by non controlling interest holders maximum percentage of eligible shares to be put each year by option exercise right			11.00%	28.00%
Description of ownership after transfer of shares	However, as the Written Put Option outstanding is legally detachable separately exercisable from the 50% minus one share of equity in Aipu Group held by the Company, the Written Put Option qualifies as a freestanding financial instrument as defined under ASC Topic 480 and the Written Put Option is accounted as derivative liability pursuant to ASC 815.
Ownership percentage after transaction		50.00%
Floor
Redeemable Noncontrolling Interest [Line Items]
Financial and operational performance targeted amount used to compute put option exercise price		$ 700,000
Ceiling
Redeemable Noncontrolling Interest [Line Items]
Financial and operational performance targeted amount used to compute put option exercise price		$ 800,000

Redeemable Noncontrolling Interests (Detail) ¥ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)	Dec. 31, 2016 CNY (¥)
Noncontrolling Interest [Abstract]
Beginning Balance			¥ 700,000	¥ 790,229
Loss for the year	$ 0	¥ 0	(141,896)	(300,713)
Increase in accretion of redeemable noncontrolling interests			141,896	210,484
Reversal due to extinguishment of put option			¥ (700,000)
Ending Balance	$ 0	¥ 0		¥ 700,000

Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) ¥ in Thousands, $ in Thousands	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value on recurring basis	$ 209,727	¥ 1,441,976	¥ 1,426,213
Liabilities measured at fair value on recurring basis	296,027	2,035,331	2,029,128
Available-for-sales Debt Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value on recurring basis	369	2,537	2,537
Bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities measured at fair value on recurring basis	295,304	2,030,361	1,980,529
Liability Classified RSU
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities measured at fair value on recurring basis	723	4,970	11,865
Business Acquisition Contingent Purchase Consideration \| Due to related parties
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities measured at fair value on recurring basis			36,734
Bank Time Deposits \| Short-term investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value on recurring basis	35,636	245,014	548,890
Bank Time Deposits \| Cash equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value on recurring basis	$ 173,722	1,194,425	874,786
Quoted prices in active markets for identical assets and liabilities (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value on recurring basis		1,439,439	1,423,676
Liabilities measured at fair value on recurring basis		2,030,361	1,980,529
Quoted prices in active markets for identical assets and liabilities (Level 1) \| Bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities measured at fair value on recurring basis		2,030,361	1,980,529
Quoted prices in active markets for identical assets and liabilities (Level 1) \| Bank Time Deposits \| Short-term investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value on recurring basis		245,014	548,890
Quoted prices in active markets for identical assets and liabilities (Level 1) \| Bank Time Deposits \| Cash equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value on recurring basis		1,194,425	874,786
Unobservable inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value on recurring basis		2,537	2,537
Liabilities measured at fair value on recurring basis		4,970	48,599
Unobservable inputs (Level 3) \| Available-for-sales Debt Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value on recurring basis		2,537	2,537
Unobservable inputs (Level 3) \| Liability Classified RSU
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities measured at fair value on recurring basis		¥ 4,970	11,865
Unobservable inputs (Level 3) \| Business Acquisition Contingent Purchase Consideration \| Due to related parties
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities measured at fair value on recurring basis			¥ 36,734

Reconciliation of Liabilities Measured at Fair Value on Recurring Basis Using Significant Unobservable Inputs Level Three (Detail) ¥ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)
Business Acquisition Contingent Purchase Consideration
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance		¥ 36,734	¥ 65,797
Changes in the fair value		(13,905)	937
Ending Balance			36,734
Business Acquisition Contingent Purchase Consideration \| Payment of cash consideration
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Bonuses settled in cash during 2017		(22,829)	(30,000)
Share-settled bonuses
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance			37,526
Changes in the fair value			(810)
Reclassification to equity			(22,752)
Bonuses settled in cash during 2017			(13,964)
Transfers in and/or out of Level 3
Ending Balance
Liability Classified RSU
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance		11,865	34,612
Increase in liability classified RSU			61,903
Reclassification to equity		(587)	(84,650)
Reversal of share-settled bonus		(6,308)
Ending Balance	$ 723	¥ 4,970	¥ 11,865

Capital Commitments (Detail) - Dec. 31, 2018 - Capital Commitments - Computer and Network Equipment and Construction in Progress ¥ in Thousands, $ in Thousands	USD ($)	CNY (¥)
Long-term Purchase Commitment [Line Items]
2019	$ 167,104	¥ 1,148,922
2020	40,947	281,529
2021	21,469	147,609
2022	15,220	104,645
2023 and thereafter	103,062	708,597
Purchase Obligation, Total	$ 347,802	¥ 2,391,302

Commitments and Contingencies - Additional Information (Detail) ¥ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)	Dec. 31, 2016 CNY (¥)	Dec. 31, 2018 CNY (¥)	Apr. 09, 2018 USD ($)	Apr. 09, 2018 CNY (¥)	Dec. 31, 2012 CNY (¥)
Commitments and Contingencies [Line Items]
Operating leases in PRC, Hongkong and United States, total rental expenses	$ 20,020	¥ 137,649	¥ 89,780	¥ 93,869
Fair value of contingent consideration								¥ 47,755
Noncurrent Liability
Commitments and Contingencies [Line Items]
Accrual for unrecognized tax benefits and interest	$ 971				¥ 6,677
Securities Litigation
Commitments and Contingencies [Line Items]
Litigation settlement amount						$ 9,000	¥ 58,808
Accrued liability for legal contingencies			¥ 10,007

Future Minimum Lease Payments Under Non Cancelable Operating Leases (Detail) - Dec. 31, 2018 ¥ in Thousands, $ in Thousands	USD ($)	CNY (¥)
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
2019	$ 24,930	¥ 171,404
2020	19,092	131,268
2021	22,024	151,428
2022	13,966	96,025
2023 and thereafter	118,370	813,854
Operating Leases, Future Minimum Payments Due, Total	$ 198,382	¥ 1,363,979

Purchase Commitments (Detail) - Dec. 31, 2018 - Purchase Commitments - Bandwidth and Cabinet Capacity ¥ in Thousands, $ in Thousands	USD ($)	CNY (¥)
Long-term Purchase Commitment [Line Items]
2019	$ 69,836	¥ 480,159
2020	28,547	196,274
2021	7,787	53,537
2022	7,442	51,166
2023 and thereafter	1,300	8,942
Purchase Obligation, Total	$ 114,912	¥ 790,078

Subsequent Events - Additional information (Detail) ¥ in Thousands, $ in Thousands	Dec. 31, 2018 CNY (¥)	Dec. 25, 2018 USD ($)	Dec. 25, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)	Dec. 31, 2016 CNY (¥)
Schedule of Equity Method Investments [Line Items]
Total consideration	¥ 521,863			¥ 312,176	¥ 150,000
Beijing Shuhai Data Technology Co Ltd [Member]
Schedule of Equity Method Investments [Line Items]
Equity interest, percentage		100.00%	100.00%
Total consideration		$ 14,544	¥ 100,000

Condensed Balance Sheets (Detail) ¥ in Thousands, $ in Thousands	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)	Dec. 31, 2016 CNY (¥)
Current assets
Cash and cash equivalents	$ 343,038	¥ 2,358,556	¥ 1,949,631	¥ 1,297,418
Restricted cash	38,574	265,214	242,494	¥ 1,963,561
Short-term investments	35,636	245,014	548,890
Prepaid expenses and other current assets	168,385	1,157,740	933,750
Amount due from a related party	18,245	125,446	114,256
Total current assets	680,402	4,678,109	4,245,542
Non-current assets
Total non-current assets	941,402	6,472,608	5,662,619
Total assets	1,621,804	11,150,717	9,908,161
Current liabilities:
Accrued expenses and other payables	95,894	659,320	657,133
Interest payable	7,909	54,376	57,359
Amount due to a related party	7,611	52,328	55,675
Total current liabilities	318,699	2,191,210	1,764,184
Non-current liabilities
Bonds payable	296,391	2,037,836	1,929,208
Total non-current liabilities	523,063	3,596,323	2,942,973
Total liabilities	841,762	5,787,533	4,707,157
Shareholders' equity:
Additional paid-incapital	1,329,575	9,141,494	8,980,407
Accumulated other comprehensive (loss) income	12,505	85,979	(2,673)
Accumulated deficit	(558,219)	(3,838,032)	(3,629,300)
Treasury stock	(49,114)	(337,683)	(337,683)
Total 21Vianet Group, Inc. shareholders' equity	740,921	5,094,207	5,049,533
Total liabilities and shareholders' equity	1,621,804	11,150,717	9,908,161
Parent Company
Current assets
Cash and cash equivalents	85,880	590,470	845,632
Restricted cash			71,412
Short-term investments	21,961	150,990	548,873
Prepaid expenses and other current assets	14,303	98,337	131,834
Amount due from a related party			26,137
Amounts due from subsidiaries	736,259	5,062,149	4,285,743
Total current assets	858,403	5,901,946	5,909,631
Non-current assets
Investments in subsidiaries and Consolidated VIEs	198,485	1,364,685	1,259,455
Total non-current assets	198,485	1,364,685	1,259,455
Total assets	1,056,888	7,266,631	7,169,086
Current liabilities:
Accrued expenses and other payables	8,241	56,656	70,504
Accounts payable	396	2,725	6,351
Interest payable	7,849	53,965	56,809
Amount due to a related party			39,068
Amounts due to subsidiaries	3,090	21,242	17,613
Total current liabilities	19,576	134,588	190,345
Non-current liabilities
Bonds payable	296,391	2,037,836	1,929,208
Total non-current liabilities	296,391	2,037,836	1,929,208
Total liabilities	315,967	2,172,424	2,119,553
Shareholders' equity:
Additional paid-incapital	1,329,574	9,141,494	8,980,407
Accumulated other comprehensive (loss) income	12,505	85,979	(2,673)
Accumulated deficit	(552,051)	(3,795,629)	(3,590,564)
Treasury stock	(49,114)	(337,683)	(337,683)
Total 21Vianet Group, Inc. shareholders' equity	740,921	5,094,207	5,049,533
Total liabilities and shareholders' equity	1,056,888	7,266,631	7,169,086
Class A Ordinary Shares
Shareholders' equity:
Ordinary shares	5	34	34
Class A Ordinary Shares \| Parent Company
Shareholders' equity:
Ordinary shares	5	34	34
Class B Ordinary Shares
Shareholders' equity:
Ordinary shares	2	12	12
Class B Ordinary Shares \| Parent Company
Shareholders' equity:
Ordinary shares	$ 2	¥ 12	¥ 12

Condensed Balance Sheets (Parenthetical) (Detail) - $ / shares	Dec. 31, 2018	Dec. 31, 2017
Class A Ordinary Shares
Condensed Balance Sheet Statements, Captions [Line Items]
Ordinary shares, par value (in dollars per share)	$ 0.00001
Ordinary shares, shares authorized (in shares)	1,200,000,000	1,200,000,000
Ordinary shares, shares issued (in shares)	499,706,628	496,636,128
Ordinary shares, shares outstanding (in shares)	499,706,628	496,636,128
Class B Ordinary Shares
Condensed Balance Sheet Statements, Captions [Line Items]
Ordinary shares, par value (in dollars per share)	$ 0.00001
Ordinary shares, shares authorized (in shares)	300,000,000	300,000,000
Ordinary shares, shares issued (in shares)	174,649,638	174,649,638
Ordinary shares, shares outstanding (in shares)	174,649,638	174,649,638
Parent Company \| Class A Ordinary Shares
Condensed Balance Sheet Statements, Captions [Line Items]
Ordinary shares, par value (in dollars per share)	$ 0.00001
Ordinary shares, shares authorized (in shares)	1,200,000,000	1,200,000,000
Ordinary shares, shares issued (in shares)	499,706,628	496,636,128
Ordinary shares, shares outstanding (in shares)	499,706,628	496,636,128
Parent Company \| Class B Ordinary Shares
Condensed Balance Sheet Statements, Captions [Line Items]
Ordinary shares, par value (in dollars per share)	$ 0.00001
Ordinary shares, shares authorized (in shares)	300,000,000	300,000,000
Ordinary shares, shares issued (in shares)	174,649,638	174,649,638
Ordinary shares, shares outstanding (in shares)	174,649,638	174,649,638

Condensed Statements of Operations (Detail) ¥ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)	Dec. 31, 2016 CNY (¥)
Operating Expenses
General and administrative expenses	$ (67,288)	¥ (462,637)	¥ (519,950)	¥ (639,648)
Changes in the fair value of contingent purchase consideration payables	2,022	13,905	(937)	93,307
Operating profit (loss)	34,538	237,479	(1,368,538)	(840,196)
Loss before income taxes	(23,611)	(162,325)	(1,007,814)	(943,082)
Income tax expenses	(3,550)	(24,411)	90,170	11,160
Net loss attributable to the Company's ordinary shareholders	(29,827)	(205,065)	(772,730)	(633,598)
Parent Company
Operating Expenses
General and administrative expenses	(9,592)	(65,949)	(145,890)	(124,450)
Changes in the fair value of contingent purchase consideration payables	2,022	13,905	(937)	93,307
Operating profit (loss)	(7,570)	(52,044)	(146,827)	(31,143)
Other loss	(38,134)	(262,186)	(95,210)	(169,915)
Loss before income taxes	(29,827)	(205,065)	(772,730)	(633,598)
Income tax expenses	0	0	0	0
Net loss attributable to the Company's ordinary shareholders	(29,827)	(205,065)	(772,730)	(633,598)
Parent Company \| Subsidiaries and Consolidated VIEs
Operating Expenses
Operating profit (loss)	$ 15,877	¥ 109,165	¥ (530,693)	¥ (432,540)

Condensed Statement of Comprehensive Loss (Detail) ¥ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)	Dec. 31, 2016 CNY (¥)
Condensed Consolidating Statement of Other Comprehensive Income (Loss) [Line Items]
Net loss	$ (29,827)	¥ (205,065)	¥ (772,730)	¥ (633,598)
Other comprehensive income (loss), net of tax of nil:
Foreign currency translation adjustments, net of tax of nil	12,894	88,652	(120,963)	142,526
Comprehensive loss	(14,267)	(98,084)	(1,038,607)	(789,396)
Comprehensive loss attributable to the Company's ordinary shareholders	(16,933)	(116,413)	(893,693)	(491,072)
Parent Company
Condensed Consolidating Statement of Other Comprehensive Income (Loss) [Line Items]
Net loss	(29,827)	(205,065)	(772,730)	(633,598)
Other comprehensive income (loss), net of tax of nil:
Foreign currency translation adjustments, net of tax of nil	12,894	88,652	(120,963)	142,526
Other comprehensive income (loss), net of tax of nil:	12,894	88,652	(120,963)	142,526
Comprehensive loss	(16,933)	(116,413)	(893,693)	(491,072)
Comprehensive loss attributable to the Company's ordinary shareholders	$ (16,933)	¥ (116,413)	¥ (893,693)	¥ (491,072)

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References + Details

Condensed Statement of Comprehensive Loss (Parenthetical) (Detail) ¥ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)	Dec. 31, 2016 CNY (¥)
Condensed Consolidating Statement of Other Comprehensive Income (Loss) [Line Items]
Foreign currency translation adjustments, tax	$ 0	¥ 0	¥ 0	¥ 0
Parent Company
Condensed Consolidating Statement of Other Comprehensive Income (Loss) [Line Items]
Foreign currency translation adjustments, tax	0	0	0	0
Other comprehensive income, tax	$ 0	¥ 0	¥ 0	¥ 0

Condensed Statements of Cash Flows (Detail) ¥ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)	Dec. 31, 2016 CNY (¥)
Condensed Cash Flow Statements, Captions [Line Items]
Net cash used in operating activities	$ 102,534	¥ 704,966	¥ 487,202	¥ 57,569
Net cash used in investing activities	(44,337)	(304,846)	(833,307)	(841,017)
Net cash generated from (used in) financing activities	(2,896)	(19,901)	(612,651)	1,908,883
Cash and cash equivalents and restricted cash at beginning of the year	319,318	2,195,469	3,294,523	2,008,799
Cash and cash equivalents and restricted cash at end of the year	387,030	2,661,021	2,195,469	3,294,523
Parent Company
Condensed Cash Flow Statements, Captions [Line Items]
Net cash used in operating activities	(24,154)	(166,068)	(18,324)	(78,567)
Net cash used in investing activities	(29,620)	(203,651)	(1,291,042)	(617,613)
Net cash generated from (used in) financing activities	6,275	43,145	(130,187)	2,254,577
Net increase (decrease) in cash and cash equivalents and restricted cash	(47,499)	(326,574)	(1,439,553)	1,558,397
Cash and cash equivalents and restricted cash at beginning of the year	133,379	917,044	2,356,597	798,200
Cash and cash equivalents and restricted cash at end of the year	$ 85,880	¥ 590,470	¥ 917,044	¥ 2,356,597

Related Party Balances Parent Company Only (Detail) ¥ in Thousands, $ in Thousands	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)
Amount due from related parties current
Amount due from related parties current	$ 18,245	¥ 125,446	¥ 114,256
Amount due to related parties
Amounts due to related parties of the consolidated VIEs without resource to the primary beneficiaries	7,611	52,328	55,675
Seller of iJoy
Amount due from related parties current
Amount due from related parties current			26,137
Amount due to related parties
Amounts due to related parties of the consolidated VIEs without resource to the primary beneficiaries			39,068
Parent Company
Amount due from subsidiaries current
Amount due from subsidiaries current	736,259	5,062,149	4,285,743
Amount due from related parties current
Amount due from related parties current			26,137
Amounts due to subsidiaries
Amount due to subsidiaries current	3,090	21,242	17,613
Amount due to related parties
Amounts due to related parties of the consolidated VIEs without resource to the primary beneficiaries			39,068
Parent Company \| 21Vianet Hong Kong Entities
Amount due from subsidiaries current
Amount due from subsidiaries current	718,292	4,938,618	4,143,269
Parent Company \| Hong Kong Fastweb Holdings Co., Limited ("Fastweb HK")
Amount due from subsidiaries current
Amount due from subsidiaries current	9,596	65,976	61,637
Parent Company \| 21Vianet Mobile Limited ("21V Mobile")
Amount due from subsidiaries current
Amount due from subsidiaries current	7,647	52,579	50,453
Parent Company \| Venture
Amount due from subsidiaries current
Amount due from subsidiaries current			25,549
Parent Company \| WiFire Open Network Group Ltd
Amount due from subsidiaries current
Amount due from subsidiaries current	622	4,277	4,170
Parent Company \| WiFire Group Inc. ("WiFire Group")
Amount due from subsidiaries current
Amount due from subsidiaries current	100	686	653
Parent Company \| Other Subsidiaries
Amount due from subsidiaries current
Amount due from subsidiaries current	2	13	12
Amounts due to subsidiaries
Amount due to subsidiaries current	421	2,891	18
Parent Company \| Seller of iJoy
Amount due from related parties current
Amount due from related parties current			26,137
Amount due to related parties
Amounts due to related parties of the consolidated VIEs without resource to the primary beneficiaries			39,068
Parent Company \| Beijing 21Vianet Zhi Hui Neng Yuan System Technology Company Limited
Amounts due to subsidiaries
Amount due to subsidiaries current	$ 2,669	¥ 18,351	¥ 17,595

Parent Company Only Condensed Financial Information - Additional Information (Detail) ¥ in Thousands			12 Months Ended
	Sep. 29, 2017 USD ($)	Aug. 17, 2017 CNY (¥)	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CNY (¥)	Dec. 31, 2017 CNY (¥)	Dec. 31, 2016 CNY (¥)	Aug. 17, 2017 USD ($)
Condensed Financial Statements, Captions [Line Items]
Operating leases, total rental expenses			$ 20,020,000	¥ 137,649	¥ 89,780	¥ 93,869
Proceeds from issuance of Notes, net					1,936,154
Bonds 7% Due 2020
Condensed Financial Statements, Captions [Line Items]
Debt instrument, face amount \| $	$ 100,000,000						$ 200,000,000
Debt instrument, stated rate	7.00%						7.00%
Debt instrument, maturity date	Aug. 17, 2020	Aug. 17, 2020
Debt instrument, frequency of periodic payment		Payable semi-annually in arrears on August 17 and February 17 in each year
Debt instrument, premium price	1.0004
Debt instrument, effective yield	6.98%
Proceeds from issuance of Notes, net		¥ 1,926,419
Parent Company \| UNITED STATES
Condensed Financial Statements, Captions [Line Items]
Operating leases, total rental expenses			$ 1,578,000	¥ 10,848	¥ 5,366	¥ 15,824
Operating leases, expiration date			Mar. 01, 2025	Mar. 01, 2025
Parent Company \| Bonds 7% Due 2020
Condensed Financial Statements, Captions [Line Items]
Debt instrument, face amount \| $	$ 100,000,000						$ 200,000,000
Debt instrument, stated rate	7.00%						7.00%
Debt instrument, maturity date			Aug. 17, 2020	Aug. 17, 2020
Debt instrument, frequency of periodic payment			Notes is payable semi-annually in arrears on August 17 and February 17 in each year	Notes is payable semi-annually in arrears on August 17 and February 17 in each year
Debt instrument, date of first required payment			Feb. 17, 2018	Feb. 17, 2018
Debt instrument, premium price	1.0004
Debt instrument, effective yield	6.98%
Proceeds from issuance of Notes, net				¥ 1,926,419

Future Minimum Lease Payments Under Non Cancelable Operating Leases Parent Company (Detail) - Dec. 31, 2018 ¥ in Thousands, $ in Thousands	USD ($)	CNY (¥)
Operating Leased Commitments [Line Items]
2019	$ 24,930	¥ 171,404
2020	19,092	131,268
2021	22,024	151,428
2022	13,966	96,025
2023 and thereafter	118,370	813,854
Operating Leases, Future Minimum Payments Due	198,382	1,363,979
Parent Company
Operating Leased Commitments [Line Items]
2019	1,146	7,878
2020	1,100	7,564
2021	1,100	7,564
2022	1,100	7,564
2023 and thereafter	1,300	8,941
Operating Leases, Future Minimum Payments Due	$ 5,746	¥ 39,511