LONG-TERM DEBT - Net Interest Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Debt Disclosure [Abstract]
Interest expense	$ 21,668	$ 20,723	$ 64,285	$ 65,783
Amortization of deferred financing costs	1,342	999	3,580	2,942
Amortization of original issue premium of senior notes	(241)	(849)	(1,331)	(2,546)
Interest income and other investment income	2	(27)	(50)	(70)
Total net interest expense	$ 22,771	$ 20,846	$ 66,484	$ 66,109