SEGMENT DISCLOSURE - Segment Net Operating Income (Loss) (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020 USD ($) property	Sep. 30, 2019 USD ($) property	Sep. 30, 2020 USD ($) property	Sep. 30, 2019 USD ($) property
Segment Reporting Information [Line Items]
Number of types of commercial real estate properties (in properties) | property	2	2	2	2
Revenues	$ 17,334	$ 29,215	$ 59,379	$ 113,348
EXPENSES:
Interest expense	2,643	2,403	8,706	8,998
General and administrative	1,736	1,384	5,138	4,793
EXPENSES	22,682	26,574	70,737	198,720
Hotel
Segment Reporting Information [Line Items]
Revenues	1,762	8,511	11,129	29,430
Reportable segments
EXPENSES:
Expense reimbursements to related parties	901	652	2,581	1,840
Segment net operating income (loss)	6,642	12,927	25,208	55,754
Reportable segments | Office
Segment Reporting Information [Line Items]
Revenues	13,529	16,885	42,189	72,380
EXPENSES:
Operating	6,026	7,205	17,338	29,677
General and administrative	61	41	397	397
EXPENSES	6,087	7,246	17,735	30,074
Segment net operating income (loss)	7,442	9,639	24,454	42,306
Reportable segments | Hotel
Segment Reporting Information [Line Items]
Revenues	1,762	8,511	11,129	29,430
EXPENSES:
Operating	2,796	6,081	11,491	19,520
General and administrative	35	31	54	108
EXPENSES	2,831	6,112	11,545	19,628
Segment net operating income (loss)	(1,069)	2,399	(416)	9,802
Reportable segments | Lending
Segment Reporting Information [Line Items]
Revenues	1,981	2,411	5,963	8,312
EXPENSES:
Interest expense	170	365	650	1,483
Expense reimbursements to related parties	901	652	2,581	1,840
General and administrative	641	505	1,562	1,343
EXPENSES	1,712	1,522	4,793	4,666
Segment net operating income (loss)	$ 269	$ 889	$ 1,170	$ 3,646