SEGMENT DISCLOSURE - Operating Income (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018 USD ($) property	Jun. 30, 2017 USD ($) property	Jun. 30, 2018 USD ($) property	Jun. 30, 2017 USD ($) property
Segment Reporting [Abstract]
Number of types of commercial real estate properties | property	2	3	2	3
Segment disclosure
Revenues	$ 51,559	$ 61,299	$ 99,957	$ 128,248
Expenses:
Interest expense	6,811	9,513	13,444	19,286
General and administrative	1,915	1,647	5,291	3,326
EXPENSES	49,318	85,748	96,706	146,104
Segment net operating income	29,352	32,469	57,577	74,584
Office
Segment disclosure
Revenues	37,904	43,914	72,820	93,007
Expenses:
Operating	13,943	17,804	25,430	31,557
General and administrative	98	394	979	682
EXPENSES	14,041	18,198	26,409	32,239
Segment net operating income	23,863	25,716	46,411	60,768
Hotel
Segment disclosure
Revenues	10,947	10,604	21,438	21,122
Expenses:
Operating	6,837	6,586	13,370	13,025
General and administrative	0	35	18	39
EXPENSES	6,837	6,621	13,388	13,064
Segment net operating income	4,110	3,983	8,050	8,058
Multifamily
Segment disclosure
Revenues	0	4,714	0	9,717
Expenses:
Operating	0	2,859	0	5,627
General and administrative	0	113	0	342
EXPENSES	0	2,972	0	5,969
Segment net operating income	0	1,742	0	3,748
Lending
Segment disclosure
Revenues	2,708	2,067	5,699	4,402
Expenses:
Interest expense	300	(55)	484	87
Fees to related party	639	784	1,240	1,628
General and administrative	390	310	859	677
EXPENSES	1,329	1,039	2,583	2,392
Segment net operating income	1,379	1,028	3,116	2,010
Reportable segments
Expenses:
Segment net operating income	$ 29,352	$ 32,469	$ 57,577	$ 74,584