Leases - Components of Lease Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
Operating lease cost	$ 90,212	$ 106,085
Financing lease cost:
Amortization of right-of-use assets	1,755	1,317
Interest on lease liabilities	86	71
Total finance lease cost	1,841	1,388
Variable lease cost	38,208	40,786
Sublease income	(38,622)	(55,522)
Net lease cost	$ 91,639	$ 92,737