LEASES - Components of Lease Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Components of lease expense:
Operating lease cost	$ 6,044	$ 5,841	$ 11,833	$ 11,095
Finance lease cost:
Amortization of right-of-use assets	1,099	906	2,075	2,105
Interest on lease liabilities	375	369	687	717
Total finance lease cost	1,474	1,275	2,762	2,822
Short-term lease and variable lease costs	$ 2,444	$ 2,430	$ 5,572	$ 4,878