BASIS OF PRESENTATION AND SIGNIFICANT ACCOUNTING POLICIES - Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Disaggregation of Revenue [Line Items]
Fixed lease income - operating leases	$ 41,712	$ 45,164	$ 125,555	$ 133,248
Variable lease income - operating leases	1,729	1,367	4,811	3,999
Revenues	44,138	47,436	132,454	139,978
Other Property Revenue
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 697	$ 905	$ 2,088	$ 2,731