BASIS OF PRESENTATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Revenue Recognition (Details) - USD ($)	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 payments	$ 12,382,000	$ 15,389,000	$ 38,294,000	$ 66,925,000
Variable lease payments	515,000	1,917,000	3,122,000	6,381,000
Rental and other property income	12,897,000	17,306,000	41,416,000	73,306,000
Hotel income	1,525,000	7,734,000	10,153,000	27,087,000
Rental and other property income	12,897,000	17,306,000	41,416,000	73,306,000
Interest and other income	2,912,000	4,175,000	7,810,000	12,955,000
REVENUES	17,334,000	29,215,000	59,379,000	113,348,000
Tenant recoveries outside of lease agreements	0	0	0	205,000
Remaining performance obligations	0		0
Hotel
Disaggregation of Revenue [Line Items]
Hotel income	1,525,000	7,734,000	10,153,000	27,087,000
Rental and other property income	222,000	736,000	911,000	2,208,000
Interest and other income	15,000	41,000	65,000	135,000
REVENUES	$ 1,762,000	$ 8,511,000	$ 11,129,000	$ 29,430,000