Leases - Cost (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Lessee, Lease, Description [Line Items]
Lease, Cost, Total	$ 24,970	$ 24,544
Vehicle Rents and General and Other Operating [Member]
Lessee, Lease, Description [Line Items]
Operating lease cost	23,091	21,915
Short-term lease cost	1,343	2,018
Depreciation and Amortization [Member]
Lessee, Lease, Description [Line Items]
Amortization of finance lease assets	428	438
Interest Expense [Member]
Lessee, Lease, Description [Line Items]
Interest on lease liabilities	$ 108	$ 173