Supplemental Cash Flow Information - Schedule of Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Noncash or Part Noncash Acquisitions [Line Items]
Cash payments for interest to third parties	$ 11,976	$ 4,668
Cash payments for interest to related parties	0	382
Non-cash investing and financing activities:
Capital expenditures included in accounts payable and accrued liabilities	8,538	11,006
Capital expenditures financed through long-term debt	10,139	7,988
Debt issuance costs included in accounts payable and accrued liabilities	1,733	0
Property and equipment acquired under capital leases	3,369	0
Accrual of return on Class C redeemable preferred units	0	9,439
Class A Convertible Preferred Stock
Non-cash investing and financing activities:
Conversion of stock, amount converted	73,880	0
Class C Redeemable Preferred Units
Non-cash investing and financing activities:
Conversion of stock, amount converted	0	260,411
Car360 | Member Units
Non-cash investing and financing activities:
Issuance of LLC Units related to business acquisitions	$ 9,981	$ 0