COMMITMENTS AND CONTINGENCIES - Capital commitments (Details) - CNY (¥) ¥ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Capital additional purchase commitments
Capital commitments
Capital commitments outstanding not provided for in the financial statements, Contracted for	¥ 3,790,769	¥ 3,949,623
Purchase of land use rights
Capital commitments
Capital commitments outstanding not provided for in the financial statements, Contracted for	¥ 90,938	¥ 20,650

Amount of the unrecorded obligation to transfer funds in the future for fixed or minimum amounts or quantities of goods or services at fixed or minimum prices (for example, as in take-or-pay contracts or throughput contracts).

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 440
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123406679&loc=d3e25336-109308

Name:	us-gaap_UnrecordedUnconditionalPurchaseObligationBalanceSheetAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant