SEGMENT DISCLOSURE - Operating Income (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017 USD ($)	Jun. 30, 2016 USD ($)	Jun. 30, 2017 USD ($) property	Jun. 30, 2016 USD ($)
Segment Reporting [Abstract]
Number of types of commercial real estate properties | property			3
Segment disclosure
Revenues	$ 61,299	$ 68,360	$ 128,248	$ 136,977
Expenses:
Interest expense	9,513	7,295	19,286	14,110
General and administrative	1,647	2,131	3,326	4,073
EXPENSES	85,748	68,699	146,104	135,572
Total segment net operating income	91,834	(339)	286,161	26,144
Reportable segments
Expenses:
Total segment net operating income	32,469	34,271	74,584	69,613
Reportable segments | Office
Segment disclosure
Revenues	43,914	45,770	93,007	91,819
Expenses:
Operating	17,804	19,930	31,557	38,417
General and administrative	394	91	682	445
EXPENSES	18,198	20,021	32,239	38,862
Total segment net operating income	25,716	25,749	60,768	52,957
Reportable segments | Hotel
Segment disclosure
Revenues	10,604	14,496	21,122	29,779
Expenses:
Operating	6,586	9,431	13,025	19,386
General and administrative	35	306	39	393
EXPENSES	6,621	9,737	13,064	19,779
Total segment net operating income	3,983	4,759	8,058	10,000
Reportable segments | Multi-family
Segment disclosure
Revenues	4,714	5,172	9,717	10,230
Expenses:
Operating	2,859	2,938	5,627	5,774
General and administrative	113	97	342	355
EXPENSES	2,972	3,035	5,969	6,129
Total segment net operating income	1,742	2,137	3,748	4,101
Reportable segments | Lending
Segment disclosure
Revenues	2,067	2,922	4,402	5,149
Expenses:
Interest expense	(55)	(7)	87	182
Fees to related party	784	884	1,628	1,814
General and administrative	310	419	677	598
EXPENSES	1,039	1,296	2,392	2,594
Total segment net operating income	$ 1,028	$ 1,626	$ 2,010	$ 2,555