DEBT - Schedule of Debt (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Sep. 30, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Carrying principal value	$ 859,784,000		$ 721,316,000
Weighted Average Maturity in Years	7 years 2 months 8 days
Annual Weighted Average Interest Rates	3.26%		3.62%
Interest Rate Swap | Designated as Hedging Instrument
Debt Instrument [Line Items]
Notional amount	$ 75,000,000		$ 195,000,000
Fixed rate	2.81%
Mortgages payable - Fannie Mae credit facility | Fannie Mae Credit Facility Agreement
Debt Instrument [Line Items]
Carrying principal value	$ 198,850,000		0
Weighted Average Maturity in Years	9 years 6 months 21 days
Annual Weighted Average Interest Rates		2.78%
Mortgages payable - other
Debt Instrument [Line Items]
Carrying principal value	$ 284,934,000		$ 298,445,000
Weighted Average Maturity in Years	4 years 11 months 4 days
Annual Weighted Average Interest Rates	3.81%		3.93%
Unsecured debt
Debt Instrument [Line Items]
Carrying principal value	$ 376,000,000		$ 422,871,000
Weighted Average Maturity in Years	7 years 10 months 2 days
Unsecured debt | Lines of credit
Debt Instrument [Line Items]
Carrying principal value	$ 76,000,000		$ 152,871,000
Weighted Average Maturity in Years	3 years 9 months
Annual Weighted Average Interest Rates	2.74%		2.85%
Unsecured debt | Term loans
Debt Instrument [Line Items]
Carrying principal value	$ 0		$ 145,000,000
Weighted Average Maturity in Years
Annual Weighted Average Interest Rates	0.00%		4.15%
Unsecured debt | Unsecured senior notes
Debt Instrument [Line Items]
Carrying principal value	$ 300,000,000		$ 125,000,000
Weighted Average Maturity in Years	8 years 7 months 17 days
Annual Weighted Average Interest Rates	3.12%		3.78%
Unsecured debt | Mortgages payable - Fannie Mae credit facility | Fannie Mae Credit Facility Agreement
Debt Instrument [Line Items]
Annual Weighted Average Interest Rates	2.78%		0.00%