Accounts Payable and Other Accrued Liabilities - Summary of Accounts Payable and Other Accrued Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Payables And Accruals [Line Items]
Accounts payable, including $9,549 and $3,891, respectively, due to related parties	$ 63,576	$ 33,032
Sales taxes and vehicle licenses and fees	45,812	27,651
Accrued compensation and benefits	21,726	13,477
Reserve for returns and cancellations	19,721	11,284
Accrued interest expense	15,650	9,206
Accrued property and equipment	23,433	7,414
Accrued advertising costs	11,403	4,398
Customer deposits	6,379	2,890
Other accrued liabilities	26,743	12,063
Total accounts payable and other accrued liabilities	234,443	121,415
Related Party
Payables And Accruals [Line Items]
Accounts payable, including $9,549 and $3,891, respectively, due to related parties	9,549	3,891
Total accounts payable and other accrued liabilities	$ 9,549	$ 3,891