SEGMENT DISCLOSURE - Reconciliation of Segment Operating Income to Net Income Attributable to Company (Details) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2021	Sep. 30, 2020
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Interest and other income	$ 6,199			$ 2,912			$ 16,231	$ 7,810
Asset management and other fees to related parties	(2,262)			(2,387)			(6,781)	(7,408)
Interest expense	(2,185)			(2,643)			(7,490)	(8,706)
General and administrative	(1,625)			(1,736)			(5,393)	(5,138)
Depreciation and amortization	(5,061)			(5,273)			(15,167)	(15,728)
Loss on early extinguishment of debt	0			(281)			0	(281)
INCOME (LOSS) BEFORE PROVISION (BENEFIT) FOR INCOME TAXES	2,570			(5,348)			796	(11,358)
(Provision) benefit for income taxes	(946)			18			(2,316)	731
NET INCOME (LOSS)	1,624	$ 527	$ (3,671)	(5,330)	$ (4,041)	$ (1,256)	(1,520)	(10,627)
Net (income) loss attributable to noncontrolling interests	0			7			4	1
NET INCOME (LOSS) ATTRIBUTABLE TO THE COMPANY	1,624			(5,323)			(1,516)	(10,626)
Operating Segments
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total segment net operating income	13,259			6,642			34,976	25,208
Expense reimbursements to related parties—corporate	(55)			(901)			(1,219)	(2,581)
Corporate and Reconciling Items
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Interest and other income	0			62			1	98
Asset management and other fees to related parties	(2,262)			(2,387)			(6,781)	(7,408)
Interest expense	(2,080)			(2,473)			(7,012)	(8,056)
General and administrative	(753)			(999)			(3,629)	(3,125)
Non-segment
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Expense reimbursements to related parties—corporate	$ (533)			$ (639)			$ (1,592)	$ (2,066)