MORTGAGE LOAN RECEIVABLES - Additional Information (Details)			3 Months Ended			12 Months Ended
		Jan. 01, 2020 USD ($) loans	Dec. 31, 2021 USD ($) loan	Dec. 31, 2020 USD ($)	Mar. 31, 2020 USD ($)	Dec. 31, 2021 USD ($) loan	Dec. 31, 2020 USD ($) security loans loan	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($) loan
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Allowance for current expected credit losses			$ 32,200,000			$ 32,200,000
General CECL Reserve		$ 11,600,000	31,752,000	$ 41,507,000		31,752,000	$ 41,507,000
Individually impaired loans			69,932,000	116,440,000		69,932,000	116,440,000
Provision for (release of) loan loss reserves				18,275,000		(8,713,000)	$ 18,275,000	$ 2,600,000
Decrease of reserve on unfunded commitments						(100,000)
Loans that previously had asset-specific reserves		3					4
Percentage of total loan portfolio		0.36%
Provision for current expected credit loss (implementation impact)(1)		$ 5,800,000				(8,605,000)	$ 18,543,000	2,600,000
Mortgage loans receivable	[1]		3,553,737,000	2,354,059,000		3,553,737,000	2,354,059,000
Loans nonaccrual status, amount			80,229,000	175,022,000		$ 80,229,000	175,022,000
Minimum
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Direct capitalization rate						4.88%			4.70%
Maximum
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Direct capitalization rate						5.23%			5.00%
Asset Specific Reserve, Company Loan
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
General CECL Reserve		14,700,000
Provision for (release of) loan loss reserves						$ (8,600,000)
Carrying value of financing receivable		39,800,000
Accounting Standards Update 2016-13
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
General CECL Reserve				42,100,000			$ 42,100,000
Number or loans in default							3
Carrying value of held for investment loan portfolio		$ 3,200,000,000
Loans that previously had asset-specific reserves | loan						3
Additional CECL reserve recorded							$ 9,100,000
Asset-specific provision related to the loans							9,200,000
Accounting Standards Update 2016-13 | Asset Specific Reserve, Company Loan
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
General CECL Reserve			20,200,000	21,400,000		$ 20,200,000	$ 21,400,000
Number or loans in default						3	4
Accounting Standards Update 2016-13 | Two Of Company Loans 1
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
General CECL Reserve					$ 7,500,000
Total mortgage loan receivables held for investment, net, at amortized cost
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Loans receivable with variable rates of interest			$ 3,300,000,000	$ 1,900,000,000		$ 3,300,000,000	$ 1,900,000,000
Loans receivable with variable rates of interest			91.50%	82.00%		91.50%	82.00%
Loans receivable with variable rates of interest, subject to interest rate floors			100.00%	100.00%		100.00%	100.00%
General CECL Reserve			$ 31,752,000	$ 41,507,000		$ 31,752,000	$ 41,507,000	$ 20,500,000	$ 17,900,000
Number or loans in default | loan			2
Loans nonaccrual status, amount				45,000,000			$ 45,000,000
Secured loan | loans							1
Total mortgage loan receivables held for investment, net, at amortized cost | Two Company Loans
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Number or loans in default						2	2
Mortgage loans receivable			$ 26,900,000			$ 26,900,000
Loans nonaccrual status, amount			24,200,000	24,200,000		24,200,000	$ 24,200,000
Total mortgage loan receivables held for investment, net, at amortized cost | One Company Loan
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
General CECL Reserve				1,200,000			$ 1,200,000
Number or loans in default							1		1
Loans nonaccrual status, amount			12,000,000	36,400,000		12,000,000	$ 36,400,000		$ 5,900,000
Total mortgage loan receivables held for investment, net, at amortized cost | Asset Specific Reserve, Company Loan
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Loan reserve amount									$ 2,700,000
Total mortgage loan receivables held for investment, net, at amortized cost | Two Of Company Loans 2
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Number or loans in default | loan									2
Total mortgage loan receivables held for investment, net, at amortized cost | Three Of Company Loans
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Loans in default, carrying value			30,500,000			30,500,000
Total mortgage loan receivables held for investment, net, at amortized cost | Two Of Company Loans 1
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
General CECL Reserve			17,500,000			$ 17,500,000			$ 10,000,000
Number or loans in default						2	2
Mortgage loans receivable			43,100,000			$ 43,100,000
Loans nonaccrual status, amount			25,600,000	27,100,000		$ 25,600,000	$ 27,100,000		45,000,000
Total mortgage loan receivables held for investment, net, at amortized cost | Two Of Company Loans 1 | Minimum
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Direct capitalization rate					7.50%	8.50%
Total mortgage loan receivables held for investment, net, at amortized cost | Two Of Company Loans 1 | Maximum
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Direct capitalization rate					8.60%	9.25%
Total mortgage loan receivables held for investment, net, at amortized cost | Two Of Company Loans 1 | Series A
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Loans nonaccrual status, amount									35,000,000
Total mortgage loan receivables held for investment, net, at amortized cost | Two Of Company Loans 1 | Series B
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Loans nonaccrual status, amount									$ 10,000,000
Total mortgage loan receivables held for investment, net, at amortized cost | One Of Company Loans 1
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Number or loans in default | security							1
Loans nonaccrual status, amount				43,800,000			$ 43,800,000
Carrying value			36,400,000			$ 36,400,000
Mortgage loan  receivables held for sale
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Loans receivable with fixed rates of interest				$ 30,500,000			$ 30,500,000
Percentage of loans receivable with fixed rates of interest				100.00%			100.00%
Loan on non-accrual status
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Loans nonaccrual status, amount			$ 0			$ 0

[1] Includes amounts relating to consolidated variable interest entities. Refer to Note 2 and Note 10.