CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Operating activities
Net loss	$ (365,540)	$ (451,910)
Adjustments to reconcile net loss to net cash used in operating activities:
Impairment charges	48,748	211,873
Gain on debt extinguishment	(37,878)	(164,684)
Depreciation and amortization	43,476	38,707
Amortization of debt issuance costs	4,598	4,809
Realized gains on securitization transactions		(45,589)
Deferred taxes	0	(23,855)
Losses on finance receivables and securitization debt, net	114,702	66,839
Stock-based compensation expense	10,051	11,957
Provision to record inventory at lower of cost or net realizable value	(2,360)	1,812
Provision for bad debt	4,074	13,406
Provision to record finance receivables held for sale at lower of cost or fair value	20,566	6,541
Amortization of unearned discounts on finance receivables at fair value	(25,954)	(14,593)
Other, net	(17,393)	(7,512)
Changes in operating assets and liabilities:
Originations of finance receivables held for sale	(582,170)	(625,575)
Principal payments received on finance receivables held for sale	105,858	64,521
Proceeds from sale of finance receivables held for sale, net		509,612
Other	(1,606)	(7,701)
Accounts receivable	754	78,060
Inventory	159,758	403,924
Prepaid expenses and other current assets	22,711	4,146
Other assets	3,266	(2,546)
Accounts payable	(7,940)	(24,281)
Accrued expenses	(24,766)	(53,553)
Deferred revenue	3,370	(65,148)
Other liabilities	(10,009)	(38,325)
Net cash used in operating activities	(533,684)	(109,065)
Investing activities
Purchases of finance receivables at fair value	(3,392)	(56,484)
Principal payments received on finance receivables at fair value	174,748	132,391
Proceeds from sale of finance receivables at fair value, net		43,262
Consolidation of VIEs	11,409
Principal payments received on beneficial interests	5,193	8,341
Purchase of property and equipment	(14,805)	(24,234)
Acquisition of business, net of cash acquired of $47.9 million		(267,488)
Net cash provided by (used in) investing activities	173,153	(164,212)
Financing activities
Proceeds from the issuance of common stock in at-the-market offering, net of offering costs	2,399
Proceeds from borrowings under secured financing agreements	261,991
Principal repayment under secured financing agreements	(208,476)	(192,839)
Proceeds from Financing of Beneficial Interests in Securitizations	24,506
Principal repayments of financing of beneficial interests in securitizations	(8,698)
Proceeds from vehicle floorplan	559,331	1,403,042
Repayments of vehicle floorplan	(685,141)	(1,638,855)
Proceeds from warehouse credit facilities	480,100	520,800
Repayments of warehouse credit facilities	(290,483)	(467,216)
Repurchases of convertible senior notes	(36,536)	(90,208)
Other financing activities	(1,653)	(4,212)
Net cash provided by (used in) financing activities	97,340	(469,488)
Net (decrease) increase in cash, cash equivalents and restricted cash	(263,191)	(742,765)
Cash, cash equivalents and restricted cash at the beginning of period	472,010	1,214,775
Cash, cash equivalents and restricted cash at the end of period	208,819	472,010
Supplemental disclosure of cash flow information:
Cash paid for interest	59,351	34,907
Cash paid for income taxes	5,363	2,409
Supplemental disclosure of non-cash investing and financing activities:
Finance receivables from consolidation of 2022-2 securitization transaction	180,706
Elimination of beneficial interest from the consolidation of 2022-2 securitization transaction	9,811
Securitization Debt From Consolidation Of Two Thousand And Twenty Two Two Securitization Transaction.	186,386
Reclassification of finance receivables held for sale to finance receivables at fair value, net	$ 248,081
Fair value of beneficial interests received in securitization transactions		$ 30,082