LEASES - Lease Expense (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2021
Operating lease expense:
Operating lease expense	$ 8,261	$ 21,811
Variable lease expense	595	1,754
Finance lease expense:
Amortization of leased assets	800	2,032
Interest on lease liabilities	115	328
Total finance lease expense	915	2,360
Total lease expense	$ 9,771	$ 25,925