SEGMENT DISCLOSURE - Operating Income (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2018 USD ($) property	Mar. 31, 2017 USD ($) property
Segment Reporting [Abstract]
Number of types of commercial real estate properties | property	2	3
Segment disclosure
Revenues	$ 48,398	$ 66,949
Expenses:
Interest expense	6,633	9,773
General and administrative	3,376	1,679
EXPENSES	47,388	60,356
Segment net operating income	1,010	194,327
Reportable segments
Expenses:
Segment net operating income	28,225	42,115
Reportable segments | Office
Segment disclosure
Revenues	34,916	49,093
Expenses:
Operating	11,487	13,753
General and administrative	881	288
EXPENSES	12,368	14,041
Segment net operating income	22,548	35,052
Reportable segments | Hotel
Segment disclosure
Revenues	10,491	10,518
Expenses:
Operating	6,533	6,439
General and administrative	18	4
EXPENSES	6,551	6,443
Segment net operating income	3,940	4,075
Reportable segments | Multi-family
Segment disclosure
Revenues	0	5,003
Expenses:
Operating	0	2,768
General and administrative	0	229
EXPENSES	0	2,997
Segment net operating income	0	2,006
Reportable segments | Lending
Segment disclosure
Revenues	2,991	2,335
Expenses:
Interest expense	184	142
Fees to related party	601	844
General and administrative	469	367
EXPENSES	1,254	1,353
Segment net operating income	$ 1,737	$ 982