Leases - Net Lease Costs (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Leases [Abstract]
Operating lease cost	$ 32,865	$ 37,961
Variable lease cost	4,302	4,403
Sublease income	(10,339)	(11,090)
Total lease cost, net	26,828	31,274
Cash paid for amounts included in the measurement of operating lease liabilities	34,927	34,936
Cash receipts from sublease arrangements	10,095	9,417
Right-of-use assets obtained in exchange for new operating lease liabilities	7,046	14,919
Cost for subleasing activities	$ 10,400	$ 10,600