DISCONTINUED OPERATIONS - Effect on Net Income from Properties Classified as Discontinued Operations (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
REVENUE	$ 46,934	$ 46,197	$ 92,542	$ 89,232
EXPENSES
Property operating expenses, excluding real estate taxes	13,942	13,934	28,746	28,180
Real estate taxes	5,574	5,003	10,806	10,024
Depreciation and amortization	18,437	19,132	36,548	39,648
General and administrative expenses	3,549	4,348	7,355	7,967
TOTAL EXPENSES	43,039	61,670	87,187	106,499
Interest expense	(7,590)	(8,562)	(15,486)	(16,858)
Other income	66	31	83	47
Gain (loss) on sale of discontinued operations			669	16,133
INCOME (LOSS) FROM DISCONTINUED OPERATIONS	0	238	0	14,120
Discontinued Operations, Disposed of by Sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
REVENUE	0	157	0	353
EXPENSES
Property operating expenses, excluding real estate taxes	0	18	0	25
Real estate taxes	0	0	0	35
Depreciation and amortization	0	0	0	2
General and administrative expenses	0	9	0	14
TOTAL EXPENSES	0	27	0	76
Operating income (loss)	0	130	0	277
Interest expense	0	0	0	(1)
Other income	0	10	0	14
Income (loss) from discontinued operations before gain (loss) on sale of discontinued operations	0	140	0	290
Gain (loss) on sale of discontinued operations	0	98	0	13,830
INCOME (LOSS) FROM DISCONTINUED OPERATIONS	$ 0	$ 238	$ 0	$ 14,120