CASH FLOW INFORMATION (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash paid for interest	$ 10,589,000	$ 9,942,000	$ 9,838,000
Cash paid for state income taxes	$ 61,000	$ 47,000	32,000
Residences at Captain Parkers LLC Residential Apartments Lexington, Massachusetts
Non-cash financing activities in connection with acquisition			$ 25,000,000