EQUITY AND MEZZANINE EQUITY - Additional Information (Details)		3 Months Ended		6 Months Ended
	Sep. 01, 2021 USD ($) apartmentCommunity $ / shares shares	Jun. 30, 2022 USD ($) $ / shares shares	Jun. 30, 2021 USD ($) apartmentProperty shares	Jun. 30, 2022 USD ($) apartmentCommunity $ / shares shares	Jun. 30, 2021 USD ($) shares	Jun. 13, 2022 USD ($)	Dec. 31, 2021 USD ($) $ / shares shares	Sep. 30, 2021 USD ($)	Dec. 31, 2019 USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock repurchase program, authorized amount						$ 50,000,000
Remaining authorized repurchase amount		$ 50,000,000		$ 50,000,000
Noncontrolling interests , operating partnership, outstanding (in shares) | shares		995,000		995,000			832,000
Noncontrolling interests , operating partnership, issued (in shares) | shares				209,000
Preferred shares, shares issued (in shares) | shares		3,881,000		3,881,000			3,881,000
Preferred shares liquidation preference		$ 97,036,000		$ 97,036,000			$ 97,036,000
Common stock outstanding (in shares) | shares		15,373,000		15,373,000			15,016,000
Sale of common shares, net			$ 54,574,000	$ 31,569,000	$ 66,356,000
Preferred shares of beneficial interest, shares outstanding (in shares) | shares		3,881,000		3,881,000			3,881,000
Preferred shares, liquidation preference (in dollars per share) | $ / shares		$ 25		$ 25			$ 25
Preferred units, shares issued (in shares) | shares		166,000		166,000			166,000
Preferred units, par value (in dollars per share) | $ / shares		$ 100		$ 100			$ 100
Preferred units, liquidation preference		$ 16,560,000		$ 16,560,000			$ 16,560,000
2022 Acquisitions, Three Apartment Communities
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of apartment homes acquired | apartmentCommunity				3
2021 Acquisitions
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of apartment homes acquired	17		0
Series E Preferred Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Preferred shares, shares issued (in shares) | shares	1,800,000
Preferred units, par value (in dollars per share) | $ / shares	$ 100
Preferred units, conversion ratio	1.2048
Preferred shares liquidation preference	$ 181,400,000
Preferred shares, dividend rate	0.03875%
Series C Preferred Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Preferred shares liquidation preference		$ 97,000,000		$ 97,000,000
Preferred shares of beneficial interest, shares outstanding (in shares) | shares		3,900,000		3,900,000			3,900,000
Preferred shares, liquidation preference (in dollars per share) | $ / shares		$ 25.00		$ 25.00
Preferred shares, annual distribution accrual rate (in dollars per share) | $ / shares				$ 1.65625
Preferred shares, dividend rate				6.625%
Series D Preferred Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Preferred units, shares issued (in shares) | shares		165,600		165,600			165,600
Preferred units, par value (in dollars per share) | $ / shares		$ 100		$ 100
Distribution rate				3.862%
Units converted, ratio		1.37931		1.37931
Preferred units, liquidation preference		$ 16,600,000		$ 16,600,000
At-The-Market Offering
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate gross sales price of common shares, authorized amount								$ 250,000,000	$ 150,000,000
Aggregate gross sales price of common shares, remaining authorized amount		$ 126,600,000		$ 126,600,000
2015 Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity awards issued (in shares) | shares		5,538	23,385	24,297	26,186
Sale of common shares, net		$ 397,000	$ 750,000	$ 619,000	$ 914,000