LEASES - Components of Lease Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Components of lease expense:
Operating lease cost	$ 5,789	$ 5,254
Finance lease cost:
Amortization of right-of-use assets	976	1,199
Interest on lease liabilities	312	348
Total finance lease cost	1,288	1,547
Short-term lease and variable lease costs	$ 3,128	$ 2,448