Cash Flows - Supplemental Disclosure of Cash Flow Information (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Cash paid during the year for:
Interest	$ 30,454	$ 33,833
Income taxes	13,538	880
Non-cash investing activities:
Derecognized property and equipment for leases that qualified as operating leases after completion of construction		(15,390)
Property and equipment acquired through third party capital lease arrangements		2,007
Leasehold improvements paid by lessor	857
Vehicles transferred to property and equipment from inventory	1,238	433
Non-cash financing activities:
Derecognized right to use liabilities for leases that qualified as operating leases after completion of construction		(15,393)
Third-party capital lease arrangements to acquire property and equipment		2,007
Non-cash distribution of equity interest in AutoMatch USA, LLC, an indirect wholly-owned subsidiary of the Company		$ (38,838)
Class A common stock issued in exchange for common units in CWGS, LLC	$ 56