LEASES - Components of Lease Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Leases [Abstract]
Operating lease costs	$ 6,784	$ 6,882	$ 21,044	$ 21,573
Variable lease costs	1,503	1,146	4,106	3,727
Finance lease costs:
Amortization of right-of-use assets	155	110	467	328
Interest on lease liabilities	84	80	252	242
Total lease cost	$ 8,526	$ 8,218	$ 25,869	$ 25,870