OPERATING PROPERTIES, REAL ESTATE HELD FOR SALE AND OTHER REAL ESTATE OWNED - REO Activity Roll Forward (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019 USD ($)	Dec. 31, 2019 Project	Dec. 31, 2018 USD ($)	Dec. 31, 2018 projects	Dec. 31, 2018 Project
Movement in Real Estate Acquired Through Foreclosure [Roll Forward]
Real Estate Held for Sale, Beginning Balances	$ 75,011		$ 64,641
Additions:
Capital costs additions	33,339		16,389
Transfer	0		0
Reductions:
Cost of properties sold	(652)		(4,754)
Impairment of real estate owned	(1,475)		(581)
Depreciation and amortization	(2,178)		(684)
General and administrative expenses			(581)
Real Estate Held for Sale, Ending Balances	104,045		75,011
Movement in Mortgage Loans On Real Estate Number Of Projects [Roll Forward]
Mortgage Loans on Real Estate, Beginning Balance | projects
Number of Projects, Reductions:
Mortgage Loans on Real Estate, Ending Balance		15		16
Operating Properties
Movement in Real Estate Acquired Through Foreclosure [Roll Forward]
Real Estate Held for Sale, Beginning Balances	33,866		20,484
Additions:
Capital costs additions	33,091		14,066
Transfer	(19,580)		0
Reductions:
Cost of properties sold	0		0
Impairment of real estate owned	0
Depreciation and amortization	(2,178)		(684)
General and administrative expenses			0
Real Estate Held for Sale, Ending Balances	45,199		33,866
Movement in Mortgage Loans On Real Estate Number Of Projects [Roll Forward]
Mortgage Loans on Real Estate, Beginning Balance		1			1
Number of Projects, Additions:
Capital costs additions | Project		0			0
Transfer | Project		0			0
Number of Projects, Reductions:
Cost of properties sold | Project		0			0
Impairment of real estate owned | Project		0
Depreciation and amortization | Project		0			0
General and administrative expenses | Project					0
Mortgage Loans on Real Estate, Ending Balance		1		1	1
Real Estate Held for Sale
Movement in Real Estate Acquired Through Foreclosure [Roll Forward]
Real Estate Held for Sale, Beginning Balances	7,418		5,853
Additions:
Capital costs additions	0		243
Transfer	19,580		6,657
Reductions:
Cost of properties sold	(18)		(4,754)
Impairment of real estate owned	(1,475)
Depreciation and amortization	0		0
General and administrative expenses			(581)
Real Estate Held for Sale, Ending Balances	25,505		7,418
Movement in Mortgage Loans On Real Estate Number Of Projects [Roll Forward]
Mortgage Loans on Real Estate, Beginning Balance		8			2
Number of Projects, Additions:
Capital costs additions | Project		1			0
Transfer | Project					8
Number of Projects, Reductions:
Cost of properties sold | Project		(1)			(2)
Impairment of real estate owned | Project		0
Depreciation and amortization | Project		0			0
General and administrative expenses | Project					0
Mortgage Loans on Real Estate, Ending Balance		8		8	8
Other Real Estate Owned
Movement in Real Estate Acquired Through Foreclosure [Roll Forward]
Real Estate Held for Sale, Beginning Balances	33,727		38,304
Additions:
Capital costs additions	248		2,080
Transfer			(6,657)
Reductions:
Cost of properties sold	(634)		0
Impairment of real estate owned	0
Depreciation and amortization	0		0
General and administrative expenses			0
Real Estate Held for Sale, Ending Balances	$ 33,341		$ 33,727
Movement in Mortgage Loans On Real Estate Number Of Projects [Roll Forward]
Mortgage Loans on Real Estate, Beginning Balance		7			15
Number of Projects, Additions:
Capital costs additions | Project		0			0
Transfer | Project					(8)
Number of Projects, Reductions:
Cost of properties sold | Project		(1)			0
Impairment of real estate owned | Project		0
Depreciation and amortization | Project		0			0
General and administrative expenses | Project					0
Mortgage Loans on Real Estate, Ending Balance		6		7	7