Leases - Lease Cost (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Finance lease cost
Amortization of finance lease ROU assets	$ 2,007	$ 1,896
Interest on lease liabilities	654	521
Operating lease cost	106,256	100,384
Variable lease cost	9,802	11,663
Short-term lease cost	1,926	1,874
Net lease cost	$ 120,645	$ 116,338