FAIR VALUE MEASUREMENTS - Financial Assets and Liabilities Not Measured at Fair Value (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
FINANCIAL LIABILITIES
Unsecured senior notes	$ 299,374	$ 299,344
Mortgages payable	874,210
Carrying Amount
FINANCIAL ASSETS
Cash and cash equivalents and restricted cash	13,156	31,267
FINANCIAL LIABILITIES
Revolving lines of credit	73,000	76,000
Unsecured senior notes	300,000	300,000
Carrying Amount | Mortgages | Mortgages payable - Fannie Mae
FINANCIAL LIABILITIES
Mortgages payable	198,850	198,850
Carrying Amount | Mortgages | Mortgages payable - other
FINANCIAL LIABILITIES
Mortgages payable	302,360	284,934
Carrying Amount | Restricted cash
FINANCIAL ASSETS
Cash and cash equivalents and restricted cash	1,914	7,358
Fair Value
FINANCIAL ASSETS
Cash and cash equivalents and restricted cash	13,156	31,267
FINANCIAL LIABILITIES
Revolving lines of credit	73,000	76,000
Unsecured senior notes	255,779	308,302
Fair Value | Mortgages | Mortgages payable - Fannie Mae
FINANCIAL LIABILITIES
Mortgages payable	170,710	198,850
Fair Value | Mortgages | Mortgages payable - other
FINANCIAL LIABILITIES
Mortgages payable	282,506	284,546
Fair Value | Restricted cash
FINANCIAL ASSETS
Cash and cash equivalents and restricted cash	$ 1,914	$ 7,358