LEASES - Components of Lease Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Components of lease expense:
Operating lease cost	$ 6,076	$ 6,001	$ 17,171	$ 17,442
Finance lease cost:
Amortization of right-of-use assets	905	1,165	3,010	3,041
Interest on lease liabilities	356	344	1,073	984
Total finance lease cost	1,261	1,509	4,083	4,025
Short-term lease and variable lease costs	$ 2,466	$ 1,757	$ 7,344	$ 6,027