SEGMENTS - Revenues and Net Operating Income for Reportable Segments (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2021 USD ($) segment	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment	1
Segment Reporting Information, Profit (Loss) [Abstract]
Revenue	$ 201,705	$ 177,994	$ 185,755
Property operating expenses, including real estate taxes	81,857	73,158	78,315
Net operating income	119,848	104,836	107,440
Property management expenses	(8,752)	(5,801)	(6,186)
Casualty loss	(344)	(1,662)	(1,116)
Depreciation and amortization	(92,165)	(75,593)	(74,271)
General and administrative expenses	(16,213)	(13,440)	(14,450)
Gain (loss) on sale of real estate and other investments	27,518	25,503	97,624
Interest expense	(29,078)	(27,525)	(30,537)
Loss on extinguishment of debt	(535)	(23)	(2,360)
Interest and other income (loss)	(2,380)	(1,552)	2,092
Income (loss) before gain on litigation settlement			78,236
Gain (loss) on litigation settlement	0	0	6,586
Net income (loss)	(2,101)	4,743	84,822
Multifamily
Segment Reporting Information, Profit (Loss) [Abstract]
Revenue	195,624	164,126	148,644
Property operating expenses, including real estate taxes	79,096	66,356	60,760
Net operating income	116,528	97,770	87,884
All Other
Segment Reporting Information, Profit (Loss) [Abstract]
Revenue	6,081	13,868	37,111
Property operating expenses, including real estate taxes	2,761	6,802	17,555
Net operating income	$ 3,320	$ 7,066	$ 19,556