RISK MANAGEMENT AND USE OF FINANCIAL INSTRUMENTS (Narrative) (Details) - USD ($) $ in Thousands	1 Months Ended		3 Months Ended			9 Months Ended		12 Months Ended
	May 31, 2020	Mar. 31, 2020	Sep. 30, 2020	Sep. 30, 2019	Jun. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2020	Dec. 31, 2019
Reclassification to earnings as interest expense			$ (262)	$ 1		$ (501)	$ 5
Amended and Restated Credit Facility
Interest rate Swap/Cap, notional amount			100,000			100,000
Scenario, Forecast [Member]
Reclassification to earnings as interest expense								$ 900
Interest Rate Cap [Member]
Interest rate Swap/Cap, notional amount	$ 100,000	$ 20,000			$ 100,000
Interest rate swap, maturity date	Mar. 24, 2023	Dec. 28, 2021			Dec. 28, 2021
Interest Rate Cap [Member] | Nondesignated [Member]
Net carrying amount of interest rate swap			$ 50			$ 50			$ 10
London Interbank Offered Rate (LIBOR) [Member] | Interest Rate Cap [Member]
Interest rate cap	0.50%	1.50%			2.50%