SEGMENT REPORTING (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2021 USD ($) segment	Mar. 31, 2020 USD ($)	Dec. 31, 2020 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment	1
Segment revenues and net operating income [Abstract]
Revenue	$ 46,648	$ 44,406
Property operating expenses, including real estate taxes	19,241	18,933
Net operating income	27,407	25,473
Property management	(1,767)	(1,554)
Casualty gain (loss)	(101)	(327)
Depreciation and amortization	(19,992)	(18,160)
General and administrative expenses	(3,906)	(3,428)
Interest expense	(7,231)	(6,911)
Interest and other income (loss)	431	(2,777)
NET INCOME (LOSS)	(5,159)	(7,684)
Segment assets
Property owned	1,883,407		$ 1,812,557
Less accumulated depreciation	(408,014)		(399,249)
Total property owned	1,475,393		1,413,308
Mortgage loans receivable at fair value	30,107		24,661
Cash and cash equivalents	10,816	26,338	392
Restricted cash	1,610	2,344	6,918
Other assets	18,427		18,904
TOTAL ASSETS	1,536,353		1,464,183
Operating Segments
Segment assets
Total property owned	1,453,567
Operating Segments | Multifamily
Segment revenues and net operating income [Abstract]
Revenue	45,983	41,845
Property operating expenses, including real estate taxes	18,881	17,660
Net operating income	27,102	24,185
Segment assets
Property owned	1,850,310		1,779,378
Less accumulated depreciation	(396,743)		(387,989)
Total property owned			1,391,389
Operating Segments | All Other
Segment revenues and net operating income [Abstract]
Revenue	665	2,561
Property operating expenses, including real estate taxes	360	1,273
Net operating income	305	$ 1,288
Segment assets
Property owned	33,097		33,179
Less accumulated depreciation	(11,271)		(11,260)
Total property owned	$ 21,826		$ 21,919