Cost incurred for outsourcing and other services provided by other entities.

No definition available.

Name:	gds_CostOfOutsourcingAndOtherServices
Namespace Prefix:	gds_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Percentage of interest transferred by the entity from a related party to holding company

+ References

No definition available.

+ Details

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Namespace Prefix:	gds_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The period within which a prior notice is to be provided requiring repayment of loans amounts due from related parties.

+ References

No definition available.

+ Details

Name:	gds_LoansAndLeasesReceivableRelatedPartiesPriorNoticeRequiringRepaymentOfLoansTerm
Namespace Prefix:	gds_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of directors replacing prior director in subsidiaries

+ References

No definition available.

+ Details

Name:	gds_NumberOfDirectorsReplacingPriorDirector
Namespace Prefix:	gds_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

For an unclassified balance sheet, reflects the carrying amount of unpaid loan amounts due from related parties at the balance sheet date.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.7(e))
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_VariableInterestEntityLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=gds_ShareholdersOfShanghaiXinwanEnterpriseManagementCo.Ltd.Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=gds_GdsBeijingAndGdsShanghaiMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ConsolidatedEntitiesAxis=us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=gds_ShanghaiXinwanEnterpriseManagementCo.Ltd.Member
Namespace Prefix:
Data Type:	na
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SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) ¥ in Thousands	1 Months Ended	12 Months Ended
	Dec. 31, 2019 CNY (¥) director	Dec. 31, 2020 CNY (¥)	Dec. 31, 2019 CNY (¥)	Dec. 31, 2018 CNY (¥)
Shareholders of Management HoldCo
VIEs financial information
Loans	¥ 1,000		¥ 1,000
GDS Beijing and GDS Shanghai
VIEs financial information
Ownership transferred (as a percent)	100.00%
Number of directors replacing prior sold director \| director	3
VIEs
VIEs financial information
Costs for outsourcing and other services provided by other consolidated entities within the Company		¥ 3,076,398	2,017,032	¥ 1,260,481
VIEs \| Management HoldCo
VIEs financial information
Loans	¥ 310,100		¥ 310,100
Right of GDS Investment Company to require repayment of the loans, prior notice period			30 days