Accounts Payable and Other Accrued Liabilities - (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Payables and Accruals [Abstract]
Accounts payable	$ 7,071	$ 6,208
Accrued property and equipment	6,326	3,045
Sales taxes and vehicle licenses and fees	4,987	4,265
Accrued compensation and benefits	3,428	3,398
Accrued advertising costs	2,912	1,281
Accrued inventory costs	1,787	3,480
Other accrued liabilities	6,444	6,487
Total accounts payable and other accrued liabilities	$ 32,955	$ 28,164