Leases - Supplemental Cash Flow (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows used for operating leases	$ 58,107	$ 69,309
Operating cash flows used for financing leases	49	32
Financing cash flows from finance leases	959	567
Right-of-use assets obtained in exchange for lease obligations:
Operating leases	(1,223)	4,156
Finance leases	$ 1,695	$ 0