Consolidated Statements of Cash Flows - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash Flows from Operating Activities:
Net loss		$ (364,639)	$ (254,745)	$ (164,316)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization expense		41,265	23,539	11,568
Loss on disposal of property and equipment		1,714	575	958
Provision for bad debt and valuation allowance		11,922	1,917	1,375
Gain on loan sales		(137,301)	(51,729)	(21,697)
Equity-based compensation expense		33,063	24,095	5,611
Amortization and write-off of debt issuance costs and bond premium		5,541	2,305	1,646
Originations of finance receivables		(2,625,351)	(1,259,539)	(529,153)
Proceeds from sale of finance receivables, net		2,643,912	1,633,519	527,265
Purchase of finance receivables		(161,781)	(387,445)	0
Principal payments received on finance receivables held for sale		85,017	0	0
Unrealized loss on beneficial interest in securitization		964	0	0
Changes in assets and liabilities:
Accounts receivable		(9,741)	(19,212)	(8,715)
Vehicle inventory		(344,861)	(183,068)	(40,839)
Other assets		(32,619)	(12,249)	(7,624)
Accounts payable and accrued liabilities		97,912	68,550	16,904
Operating lease right-of-use assets		(46,928)
Operating lease liabilities		45,195
Other liabilities		(418)	(853)	7,093
Net cash used in operating activities		(757,134)	(414,340)	(199,924)
Cash Flows from Investing Activities:
Purchases of property and equipment, including $6,282 in 2019 from related parties	[1]	(230,538)	(143,668)	(78,490)
Principal payments received on beneficial interests in securitizations		2,799	0	0
Business acquisitions, net of cash acquired		0	(6,670)	0
Net cash used in investing activities		(227,739)	(150,338)	(78,490)
Cash Flows from Financing Activities:
Proceeds from short-term revolving facilities		4,485,917	1,848,051	949,144
Payments on short-term revolving facilities		(4,219,415)	(1,899,880)	(865,665)
Proceeds from issuance of long-term debt, including $25,000(1) in 2018 from related parties	[1]	481,772	399,063	32,698
Payments on long-term debt		(15,683)	(35,522)	(2,259)
Payments of debt issuance costs, including $1,000 in 2017 to related parties		(11,445)	(11,390)	(2,055)
Net proceeds from issuance of Class A common stock		297,611	172,287	206,198
Net proceeds from issuance of Class A Convertible Preferred Stock		0	(12)
Net proceeds from issuance of Class A Convertible Preferred Stock				98,682
Proceeds from exercise of stock options		1,696	795	48
Tax withholdings related to restricted stock units and awards		(5,830)	(2,509)	(704)
Net cash provided by financing activities		1,014,623	466,264	416,087
Net increase (decrease) in cash and cash equivalents		29,750	(98,414)	137,673
Cash, cash equivalents, and restricted cash at beginning of period		88,709	187,123	49,450
Cash, cash equivalents, and restricted cash at end of period		118,459	88,709	187,123
Net proceeds from issuance of Class A Convertible Preferred Stock				98,682
Class A Convertible Preferred Stock
Cash Flows from Financing Activities:
Dividends paid on Class A Convertible Preferred Stock		0	(4,619)	0
Verde Investments, Inc.
Cash Flows from Financing Activities:
Proceeds from short-term revolving facilities		0	0	35,000
Payments on short-term revolving facilities		$ 0	$ 0	$ (35,000)

[1] A related party initially acquired $25.0 million of the senior unsecured notes during the year ended December 31, 2018, of which it subsequently disposed of $10.0 million, and held $15.0 million as of both December 31, 2019 and December 31, 2018.