CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($)	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Operating activities
Net loss	$ (310,459,000)	$ (77,189,000)
Adjustments to reconcile net loss to net cash (used in) provided by operating activities:
Goodwill impairment charge	201,703,000	0
Depreciation and amortization	7,895,000	2,906,000
Amortization of debt issuance costs	1,254,000	281,000
Realized gain on the 2022-1 securitization transaction	(29,617,000)
Deferred tax	(23,855,000)
Losses on finance receivables and securitization debt, net	15,725,000
Stock-based compensation expense	3,629,000	2,820,000
Provision to record inventory at lower of cost or net realizable value	469,000	(2,551,000)
Other	1,795,000	1,813,000
Changes in operating assets and liabilities:
Originations of finance receivables held for sale	(118,861,000)
Principal payments received on finance receivables held for sale	2,659,000
Proceeds from sale of finance receivables held for sale, net	272,309,000
Other	(1,705,000)
Accounts receivable	(4,331,000)	(33,140,000)
Inventory	(15,453,000)	88,502,000
Prepaid expenses and other current assets	6,928,000	(1,127,000)
Other assets	(2,763,000)	(650,000)
Accounts payable	(6,824,000)	9,568,000
Accrued expenses	8,036,000	12,194,000
Deferred revenue	(2,449,000)	23,376,000
Other liabilities	(21,163,000)	2,751,000
Net cash (used in) provided by operating activities	(15,078,000)	29,554,000
Investing activities
Principal payments received on finance receivables at fair value	33,570,000
Proceeds from sale of finance receivables at fair value, net	29,043,000
Principal payments received on beneficial interests	714,000
Purchase of property and equipment	(7,096,000)	(3,239,000)
Acquisition of business, net of cash acquired	(268,194,000)	(76,145,000)
Net cash used in investing activities	(211,963,000)	(79,384,000)
Financing activities
Principal repayment under secured financing agreements	(68,402,000)
Proceeds from vehicle floorplan	801,971,000	396,849,000
Repayments of vehicle floorplan	(744,831,000)	(473,042,000)
Proceeds from warehouse credit facilities	49,000,000
Repayments of warehouse credit facilities	(227,067,000)
Proceeds from exercise of stock options		2,821,000
Other financing activities	(875,000)
Net cash used in financing activities	(190,204,000)	(73,372,000)
Net decrease in cash, cash equivalents and restricted cash	(417,245,000)	(123,202,000)
Cash, cash equivalents and restricted cash at the beginning of period	1,214,775,000	1,090,039,000
Cash, cash equivalents and restricted cash at the end of period	797,530,000	966,837,000
Supplemental disclosure of cash flow information:
Cash paid for interest	5,991,000	3,525,000
Supplemental disclosure of non-cash investing and financing activities:
Fair value of beneficial interests received in securitization transactions	$ 16,473,000
Issuance of common stock for CarStory acquisition		39,030,000
Fair value of unvested stock options assumed for acquisition of business		$ 1,017,000