Leases - Net Lease Costs (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Leases [Abstract]
Operating lease cost	$ 32,583	$ 34,290	$ 98,068	$ 107,424
Variable lease cost	4,251	4,006	12,674	12,382
Sublease income	(10,721)	(6,777)	(31,644)	(28,587)
Total lease cost, net	26,113	31,519	79,098	91,219
Cash paid for amounts included in the measurement of operating lease liabilities	35,322	34,763	105,573	103,725
Cash receipts from sublease arrangements	11,669	9,592	32,128	28,512
Right-of-use assets obtained in exchange for new operating lease liabilities	18,787	527	28,081	19,061
Cost for subleasing activities	$ 10,600	$ 10,500	$ 31,800	$ 31,700