REAL ESTATE (Revenue and Expenses of Real Estate Sales) (Details) - Disposed of by Sale - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Revenues
Rental income	$ 0	$ 1,135	$ 1,802	$ 3,375
Tenant reimbursements and other operating income	0	41	110	112
Total revenues	0	1,176	1,912	3,487
Expenses
Operating, maintenance, and management	0	464	463	1,086
Real estate taxes and insurance	0	131	213	348
Asset management fees to affiliate	0	67	105	198
Depreciation and amortization	0	543	0	1,605
Interest expense	0	176	320	483
Total expenses	$ 0	$ 1,381	$ 1,101	$ 3,720