DERIVATIVE FINANCIAL INSTRUMENTS AND HEDGING ACTIVITIES - Changes in AOCI (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	$ 278,195	$ 617,275	$ 626,705
Other comprehensive income before reclassifications	0	0	1,973
Amounts reclassified (to) from accumulated other comprehensive income (loss)	0	(1,806)	(1,798)
Net current period other comprehensive income (loss)	0	(1,806)	175
Ending balance	278,114	278,195	617,275
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	0	1,806	1,631
Ending balance	$ 0	$ 0	$ 1,806