SEGMENTS - Revenues and Net Operating Income for Reportable Segments (Details)	3 Months Ended
	Mar. 31, 2023 USD ($) apartmentUnit segment	Mar. 31, 2022 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment	1
Segment revenues and net operating income [Abstract]
Revenue	$ 67,897,000	$ 60,314,000
Property operating expenses, including real estate taxes	28,923,000	25,873,000
Net operating income	38,974,000	34,441,000
Property management	(2,568,000)	(2,253,000)
Casualty gain (loss)	(252,000)	(598,000)
Depreciation and amortization	(25,993,000)	(31,001,000)
General and administrative expenses	(7,723,000)	(4,500,000)
Gain (loss) on sale of real estate and other investments	60,159,000	0
Interest expense	(10,319,000)	(7,715,000)
Interest and other income (loss)	49,000	1,063,000
Net income (loss)	52,327,000	(10,563,000)
Multifamily
Segment revenues and net operating income [Abstract]
Revenue	62,498,000	54,916,000
Property operating expenses, including real estate taxes	25,903,000	23,080,000
Net operating income	36,595,000	31,836,000
All Other
Segment revenues and net operating income [Abstract]
Revenue	5,399,000	5,398,000
Property operating expenses, including real estate taxes	3,020,000	2,793,000
Net operating income	$ 2,379,000	$ 2,605,000
All Other | Disposed of by Sale
Segment Reporting Information [Line Items]
Number of properties sold | apartmentUnit	9