Leases - Lease Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Operating leases
Operating lease right-of-use assets	$ 268,864	$ 314,526
Operating lease liabilities	315,340	365,364
Finance leases
Property and equipment, at cost	36,093	37,589
Accumulated depreciation	(24,585)	(24,579)
Finance lease liabilities	$ 11,687	$ 13,371
Finance lease, liability, noncurrent, statement of financial position [extensible list]	virt:AccountsPayableAndAccruedExpensesAndOtherLiabilities	virt:AccountsPayableAndAccruedExpensesAndOtherLiabilities