SEGMENT DISCLOSURE - Reconciliation Of Segment Operating Income (Details) - USD ($)	3 Months Ended						9 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018
Segment disclosure
Interest and other income	$ 4,175,000			$ 3,286,000			$ 12,955,000	$ 10,306,000
Asset management and other fees to related parties	(3,981,000)			(6,121,000)			(14,155,000)	(18,475,000)
Interest expense	(2,403,000)			(6,965,000)			(8,998,000)	(20,409,000)
General and administrative	(1,384,000)			(1,205,000)			(4,793,000)	(6,496,000)
Transaction costs	(340,000)			(15,000)			(600,000)	(359,000)
Depreciation and amortization	(5,180,000)			(13,310,000)			(21,995,000)	(39,783,000)
Loss on early extinguishment of debt	0			0			(29,982,000)	0
Impairment of real estate	0			0			(69,000,000)	0
Gain on sale of real estate	302,000			0			433,104,000	0
Income (loss) before provision for income taxes	2,943,000			(414,000)			347,732,000	2,837,000
Provision for income taxes	(87,000)			(115,000)			(686,000)	(795,000)
NET INCOME (LOSS)	2,856,000	$ 52,567,000	$ 291,623,000	(529,000)	$ 1,949,000	$ 622,000	347,046,000	2,042,000
Net (income) loss attributable to noncontrolling interests	(8,000)			1,000			165,000	(15,000)
NET INCOME (LOSS) ATTRIBUTABLE TO THE COMPANY	2,848,000			(528,000)			347,211,000	2,027,000
Reportable segments
Segment disclosure
Income (loss) before provision for income taxes	12,927,000			25,332,000			55,754,000	82,909,000
Corporate and Reconciling Items
Segment disclosure
Interest and other income	1,408,000			0			3,226,000	0
Asset management and other fees to related parties	(3,329,000)			(5,381,000)			(12,315,000)	(16,495,000)
Interest expense	(2,038,000)			(6,332,000)			(7,515,000)	(19,292,000)
General and administrative	$ (807,000)			$ (708,000)			$ (2,945,000)	$ (4,143,000)