SEGMENT DISCLOSURE - Operating Income (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016 USD ($)	Jun. 30, 2015 USD ($)	Jun. 30, 2016 USD ($) item	Jun. 30, 2015 USD ($)
Segment disclosure
Number of types of commercial real estate properties | item			3
Revenues	$ 65,438	$ 66,919	$ 131,828	$ 134,158
Property expenses:
General and administrative	1,712	1,955	3,475	4,547
EXPENSES	67,403	65,921	132,978	133,390
Reportable segments
Property expenses:
Total segment net operating income	32,645	33,693	67,058	67,786
Reportable segments | Office
Segment disclosure
Revenues	45,770	47,084	91,819	93,699
Property expenses:
Operating	19,930	20,060	38,417	39,451
General and administrative	91	113	445	426
EXPENSES	20,021	20,173	38,862	39,877
Total segment net operating income	25,749	26,911	52,957	53,822
Reportable segments | Hotel
Segment disclosure
Revenues	14,496	15,822	29,779	31,541
Property expenses:
Operating	9,431	9,987	19,386	20,664
General and administrative	306	38	393	79
EXPENSES	9,737	10,025	19,779	20,743
Total segment net operating income	4,759	5,797	10,000	10,798
Reportable segments | Multi-family
Segment disclosure
Revenues	5,172	4,013	10,230	8,918
Property expenses:
Operating	2,938	2,938	5,774	5,579
General and administrative	97	90	355	173
EXPENSES	3,035	3,028	6,129	5,752
Total segment net operating income	$ 2,137	$ 985	$ 4,101	$ 3,166