Leases - Lease Cost and Other Information (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Cash Flow, Operating Activities, Lessee [Abstract]
Cash paid for operating lease liabilities	$ 68,509	$ 62,873
Right-of-use assets obtained in exchange for operating lease liabilities from new leases	9,733	34,530
Right-of-use assets obtained in exchange for operating lease liabilities from lease modifications or reassessments	$ 23,155	$ 48,151
Weighted average remaining lease term:
Weighted average remaining lease term for operating leases	4 years		4 years 6 months
Operating Leases, Weighted Average Discount Rate, Percent [Abstract]
Weighted average discount rate for operating leases	2.40%		2.60%