Leases - Cost (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Lessee, Lease, Description [Line Items]
Lease, Cost, Total	$ 23,991	$ 20,939	$ 48,535	$ 42,543
Vehicle Rents and General and Other Operating [Member]
Lessee, Lease, Description [Line Items]
Operating lease cost	21,628	19,072	43,543	39,239
Short-term lease cost	1,780	792	3,798	1,103
Depreciation and Amortization [Member]
Lessee, Lease, Description [Line Items]
Amortization of finance lease assets	442	797	880	1,605
Interest Expense [Member]
Lessee, Lease, Description [Line Items]
Interest on lease liabilities	$ 141	$ 278	$ 314	$ 596