CASH FLOW INFORMATION (Details) - USD ($)	12 Months Ended			24 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2014
Cash paid for interest	$ 9,838,000	$ 8,791,000	$ 8,062,000
Cash paid for state income taxes	32,000	$ 51,000	60,000
Hamilton Green
Non-cash financing activities in connection with acquisition			$ 38,500,000
NERA Dean Street Apartments And Westgate Apartments
Non-cash financing activities in connection with acquisition				$ 7,077,000
Residences at CaptainParkers LLC Residential Apartments Lexington, Massachusetts
Non-cash financing activities in connection with acquisition	$ 25,000,000