REAL ESTATE - Office Property (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020 USD ($) ft² property	Jun. 30, 2019 USD ($)	Jun. 30, 2020 USD ($) ft² property	Jun. 30, 2019 USD ($)
Real Estate Properties [Line Items]
Other income	$ (701)	$ 269	$ (4,558)	$ 4,247
Total revenues	11,710	19,336	25,081	34,532
Total expenses	$ 17,873	22,410	$ 38,425	43,670
Office Building
Real Estate Properties [Line Items]
Number of real estate properties | property	3		3
Net rentable area | ft²	806,960		806,960
Percentage of portfolio occupied	69.00%		69.00%
Rental income	$ 6,734	7,007	$ 13,604	13,919
Other income	201	187	427	392
Total revenues	6,935	7,194	14,031	14,311
Operating, maintenance, and management	2,144	2,338	4,418	4,663
Real estate taxes and insurance	1,093	1,089	2,193	2,161
Total expenses	$ 3,237	$ 3,427	$ 6,611	$ 6,824