FAIR VALUE MEASUREMENT - Schedule of Financial Instruments Measured at Fair Value (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Assets:
Purchase options related to real estate loans	$ 7,161	$ 8,920
Liabilities:
Interest rate swaps	30,850	16,177
Recurring basis
Assets:
Purchase options related to real estate loans	7,161	8,920
Recurring basis \| Interest rate swaps
Liabilities:
Interest rate swaps	30,850	16,177
Recurring basis \| Level 1
Assets:
Purchase options related to real estate loans	0	0
Recurring basis \| Level 1 \| Interest rate swaps
Liabilities:
Interest rate swaps	0	0
Recurring basis \| Level 2
Assets:
Purchase options related to real estate loans	0	0
Recurring basis \| Level 2 \| Interest rate swaps
Liabilities:
Interest rate swaps	30,850	16,177
Recurring basis \| Level 3
Assets:
Purchase options related to real estate loans	7,161	8,920
Recurring basis \| Level 3 \| Interest rate swaps
Liabilities:
Interest rate swaps	$ 0	$ 0

Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities not subject to a master netting arrangement and not elected to be offset.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=121572278&loc=d3e13433-108611

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 55
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=99393222&loc=SL20226008-175313

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Balance Type:	credit
Period Type:	instant