DERIVATIVE FINANCIAL INSTRUMENTS AND HEDGING - Gain or Loss Recognized on Derivative Financial Instruments (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Derivative instruments, gain (loss) recognized
Total interest expense and other finance expense presented in the Consolidated Statement of Operations in which the effects of cash flow hedges are recorded	$ (43,300)	$ (41,030)	$ (41,944)
Cash flow hedges | Interest rate swaps
Derivative instruments, gain (loss) recognized
Loss recognized in Accumulated other comprehensive loss on derivative financial instruments	(22,090)	(15,327)	(3,050)
Loss reclassified from Accumulated other comprehensive loss to Interest expense	(7,417)	(731)	(150)
Total interest expense and other finance expense presented in the Consolidated Statement of Operations in which the effects of cash flow hedges are recorded	$ (43,300)	$ (41,030)	$ (41,944)