SEGMENT DISCLOSURE (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015 USD ($)	Sep. 30, 2014 USD ($)	Sep. 30, 2015 USD ($) item	Sep. 30, 2014 USD ($)
Segment disclosure
Number of types of commercial real estate properties | item			3
Revenues	$ 66,395	$ 63,117	$ 200,553	$ 190,901
Property expenses:
General and administrative	1,850	1,894	6,397	5,025
EXPENSES	66,162	62,142	199,552	180,390
Reportable segments
Property expenses:
Total segment net operating income	32,458	31,094	100,244	98,309
Reportable segments | Office
Segment disclosure
Revenues	46,427	44,378	140,126	132,833
Property expenses:
Operating	19,832	18,644	59,283	54,230
General and administrative	226	413	652	805
EXPENSES	20,058	19,057	59,935	55,035
Total segment net operating income	26,369	25,321	80,191	77,798
Reportable segments | Hotel
Segment disclosure
Revenues	15,350	13,504	46,891	42,641
Property expenses:
Operating	10,623	9,867	31,287	29,636
General and administrative	205	61	284	134
EXPENSES	10,828	9,928	31,571	29,770
Total segment net operating income	4,522	3,576	15,320	12,871
Reportable segments | Multi-family
Segment disclosure
Revenues	4,618	5,235	13,536	15,427
Property expenses:
Operating	2,906	2,485	8,485	7,155
General and administrative	145	553	318	632
EXPENSES	3,051	3,038	8,803	7,787
Total segment net operating income	$ 1,567	$ 2,197	$ 4,733	$ 7,640