PROPERTY AND EQUIPMENT, NET - Acquired under finance leases and other financing arrangement (Details) - CNY (¥) ¥ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Carrying amounts
Finance leases, net	¥ 8,867,222	¥ 8,207,825
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	Property, Plant, and Equipment and Finance Lease Right-of-Use Asset, after Accumulated Depreciation and Amortization

Indicates line item in statement of financial position that includes finance lease right-of-use asset.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=123391704&loc=SL77918631-209977

Name:	us-gaap_FinanceLeaseRightOfUseAssetStatementOfFinancialPositionExtensibleList
Namespace Prefix:	us-gaap_
Data Type:	enum2:enumerationSetItemType
Balance Type:	na
Period Type:	instant