CarGurus (CARG) 10-Q 9 Aug 23 2023 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2023	Aug. 03, 2023
Document And Entity Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2023
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q2
Entity Registrant Name	CARGURUS, INC.
Trading Symbol	CARG
Entity Central Index Key	0001494259
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Current Reporting Status	Yes
Entity File Number	001-38233
Entity Tax Identification Number	04-3843478
Entity Address, Address Line One	2 Canal Park
Entity Address, Address Line Two	4th Floor
Entity Address, City or Town	Cambridge
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02141
City Area Code	617
Local Phone Number	354-0068
Entity Interactive Data Current	Yes
Document Quarterly Report	true
Document Transition Report	false
Entity Incorporation, State or Country Code	DE
Title of 12(b) Security	Class A Common Stock, par value $0.001 per share
Security Exchange Name	NASDAQ
Class A Common Stock
Document And Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		97,499,021
Class B Common Stock
Document And Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		15,999,173

Unaudited Condensed Consolidate

Unaudited Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Current assets
Cash and cash equivalents	$ 363,060	$ 469,517
Short-term investments	90,490
Accounts receivable, net of allowance for doubtful accounts of $1,054 and $1,809, respectively	37,820	46,817
Inventory	541	5,282
Prepaid expenses, prepaid income taxes and other current assets	21,742	21,972
Deferred contract costs	10,078	8,541
Restricted cash	11,561	5,237
Total current assets	535,292	557,366
Property and equipment, net	48,243	40,128
Intangible assets, net	38,037	53,054
Goodwill	157,638	157,467
Operating lease right-of-use assets	189,905	56,869
Restricted cash		9,378
Deferred tax assets	51,888	35,488
Deferred contract costs, net of current portion	11,490	8,853
Other non-current assets	7,828	8,499
Total assets	1,040,321	927,102	[1]
Current liabilities
Accounts payable	39,260	32,529
Accrued expenses, accrued income taxes and other current liabilities	36,367	39,193
Deferred revenue	21,267	12,249
Operating lease liabilities	13,870	14,762
Total current liabilities	110,764	98,733
Operating lease liabilities	193,184	51,656
Deferred tax liabilities	43	54
Other non–current liabilities	5,611	5,301
Total liabilities	309,602	155,744
Commitments and contingencies (Note 8)
Redeemable noncontrolling interest	29,865	36,749
Stockholders’ equity:
Preferred stock, $0.001 par value per share; 10,000,000 shares authorized;no shares issued and outstanding
Additional paid-in capital	346,494	413,092
Retained earnings	355,588	323,043
Accumulated other comprehensive loss	(1,341)	(1,644)
Total stockholders’ equity	700,854	734,609
Total liabilities, redeemable noncontrolling interest and stockholders’ equity	1,040,321	927,102
Class A Common Stock
Stockholders’ equity:
Common stock	97	102
Class B Common Stock
Stockholders’ equity:
Common stock	$ 16	$ 16
[1] As of December 31, 2022, Digital Wholesale assets did not reflect certain Dealer-to-Dealer and IMCO related capitalized website development assets from the U.S. Marketplace segment. During the three months ended March 31, 2023, the Company updated Digital Wholesale assets to reflect certain Dealer-to-Dealer and IMCO related capitalized website development amortization assets from the U.S. Marketplace segment and accordingly updated Digital Wholesale assets as of December 31, 2022 for comparative purposes.

Unaudited Condensed Consolida_2

Unaudited Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Allowance for doubtful accounts	$ 807	$ 1,809
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Class A Common Stock
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	500,000,000	500,000,000
Common stock, shares issued	97,426,273	101,636,649
Common stock, shares outstanding	97,426,273	101,636,649
Class B Common Stock
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	15,999,173	15,999,173
Common stock, shares outstanding	15,999,173	15,999,173

Unaudited Condensed Consolida_3

Unaudited Condensed Consolidated Income Statements - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Revenue
Total revenue		$ 239,737	$ 511,229	$ 471,700	$ 941,837
Cost of Goods and Services Sold [Abstract]
Total cost of revenue	[1]	75,596	323,378	152,579	572,111
Gross profit		164,141	187,851	319,121	369,726
Operating expenses:
Sales and marketing		77,838	95,605	153,415	183,186
Product, technology, and development		37,391	31,354	73,998	62,007
General and administrative		27,267	33,514	52,186	66,635
Depreciation and amortization		3,907	3,836	7,725	7,697
Total operating expenses		146,403	164,309	287,324	319,525
Income from operations		17,738	23,542	31,797	50,201
Other income (expense), net:
Interest income		4,333	311	8,076	348
Other income (expense), net		347	(467)	942	(623)
Total other income (expense), net		4,680	(156)	9,018	(275)
Income before income taxes		22,418	23,386	40,815	49,926
Provision for income taxes		8,601	5,325	15,132	13,027
Consolidated net income		13,817	18,061	25,683	36,899
Net loss attributable to redeemable noncontrolling interest		(2,596)	(1,223)	(6,862)	(2,295)
Net income attributable to CarGurus, Inc.		16,413	19,284	32,545	39,194
Accretion of redeemable noncontrolling interest to redemption value			29,620		111,620
Net income (loss) attributable to common stockholders - basic		$ 16,413	$ (10,336)	$ 32,545	$ (72,426)
Net income (loss) per share attributable to common stockholders: (Note 10)
Basic		$ 0.14	$ (0.09)	$ 0.28	$ (0.61)
Diluted		$ 0.12	$ (0.09)	$ 0.22	$ (0.61)
Weighted-average number of shares of common stock used in computing net income (loss) per share attributable to common stockholders:
Basic		113,438,057	118,390,641	114,392,961	118,211,975
Diluted		114,490,651	118,390,641	115,197,890	118,211,975
Marketplace [Member]
Revenue
Total revenue		$ 170,950	$ 163,926	$ 338,077	$ 327,215
Cost of Goods and Services Sold [Abstract]
Total cost of revenue	[1]	15,474	13,257	31,007	25,466
Wholesale [Member]
Revenue
Total revenue		31,952	75,937	57,138	166,931
Cost of Goods and Services Sold [Abstract]
Total cost of revenue	[1]	24,428	46,518	46,496	104,700
Product [Member]
Revenue
Total revenue		36,835	271,366	76,485	447,691
Cost of Goods and Services Sold [Abstract]
Total cost of revenue	[1]	$ 35,694	$ 263,603	$ 75,076	$ 441,945
[1] I ncludes depreciation and amortization expense for the three months ended June 30, 2023 and 2022 and for the six months ended June 30, 2023 and 2022 of $ 7,760 , $ 7,398 , $ 15,518 and $ 14,722 , respectively.

Unaudited Condensed Consolida_4

Unaudited Condensed Consolidated Income Statements (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Income Statement [Abstract]
Depreciation and amortization expense	$ 7,760	$ 7,398	$ 15,518	$ 14,722

Unaudited Condensed Consolida_5

Unaudited Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Statement of Comprehensive Income [Abstract]
Consolidated net income	$ 13,817	$ 18,061	$ 25,683	$ 36,899
Other comprehensive income:
Foreign currency translation adjustment	(112)	(1,586)	303	(2,075)
Consolidated comprehensive income	13,705	16,475	25,986	34,824
Comprehensive loss attributable to redeemable noncontrolling interests	(2,596)	(1,223)	(6,862)	(2,295)
Comprehensive income attributable to CarGurus, Inc.	$ 16,301	$ 17,698	$ 32,848	$ 37,119

Unaudited Condensed Consolida_6

Unaudited Condensed Consolidated Statements of Redeemable Noncontrolling Interest and Stockholders' Equity - USD ($) $ in Thousands	Total	Class A Common Stock	Class B Common Stock	Common Stock Class A Common Stock	Common Stock Class B Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Loss
Beginning balance at Dec. 31, 2021	$ 516,841			$ 102	$ 16	$ 387,868	$ 129,258	$ (403)
Redeemable Noncontrolling Interest, Beginning balance at Dec. 31, 2021	162,808
Beginning balance, Shares at Dec. 31, 2021				101,773,034	15,999,173
Net (loss) income	19,910						19,910
Redeemable Noncontrolling Interest, Net income (loss)	(1,072)
Stock–based compensation expense	15,353					15,353
Issuance of common stock upon exercise of stock options	680					680
Issuance of common stock upon exercise of stock options, Shares				74,163
Issuance of common stock upon vesting of restricted stock units, Shares				451,084
Payment of withholding taxes on net share settlements of restricted stock units	(5,430)					(5,430)
Payment of withholding taxes on net share settlements of restricted stock units, Shares				(155,736)
Redeemable noncontrolling interest , accretion to redemption value	82,000
Accretion of redeemable noncontrolling interest to redemption value	(82,000)						(82,000)
Tax distribution to redeemable noncontrolling interest holders	(3,986)
Foreign currency translation adjustment	(489)							(489)
Ending balance at Mar. 31, 2022	464,865			$ 102	$ 16	398,471	67,168	(892)
Redeemable Noncontrolling Interest, Ending balance at Mar. 31, 2022	239,750
Ending balance, Shares at Mar. 31, 2022				102,142,545	15,999,173
Beginning balance at Dec. 31, 2021	516,841			$ 102	$ 16	387,868	129,258	(403)
Redeemable Noncontrolling Interest, Beginning balance at Dec. 31, 2021	162,808
Beginning balance, Shares at Dec. 31, 2021				101,773,034	15,999,173
Net (loss) income	39,194
Payment of withholding taxes on net share settlements of restricted stock units, Shares		(303,269)
Foreign currency translation adjustment	(2,075)
Ending balance at Jun. 30, 2022	461,835			$ 102	$ 16	407,363	56,832	(2,478)
Redeemable Noncontrolling Interest, Ending balance at Jun. 30, 2022	264,505
Ending balance, Shares at Jun. 30, 2022				102,465,807	15,999,173
Beginning balance at Mar. 31, 2022	464,865			$ 102	$ 16	398,471	67,168	(892)
Redeemable Noncontrolling Interest, Beginning balance at Mar. 31, 2022	239,750
Beginning balance, Shares at Mar. 31, 2022				102,142,545	15,999,173
Net (loss) income	19,284						19,284
Redeemable Noncontrolling Interest, Net income (loss)	(1,223)
Stock–based compensation expense	14,697					14,697
Issuance of common stock upon exercise of stock options	25					25
Issuance of common stock upon exercise of stock options, Shares				23,240
Issuance of common stock upon vesting of restricted stock units, Shares				447,555
Payment of withholding taxes on net share settlements of restricted stock units	(5,830)					(5,830)
Payment of withholding taxes on net share settlements of restricted stock units, Shares		(147,533)		(147,533)
Redeemable noncontrolling interest , accretion to redemption value	29,620
Accretion of redeemable noncontrolling interest to redemption value	(29,620)						(29,620)
Tax distribution to redeemable noncontrolling interest holders	(3,642)
Foreign currency translation adjustment	(1,586)							(1,586)
Ending balance at Jun. 30, 2022	461,835			$ 102	$ 16	407,363	56,832	(2,478)
Redeemable Noncontrolling Interest, Ending balance at Jun. 30, 2022	264,505
Ending balance, Shares at Jun. 30, 2022				102,465,807	15,999,173
Beginning balance at Dec. 31, 2022	734,609			$ 102	$ 16	413,092	323,043	(1,644)
Redeemable Noncontrolling Interest, Beginning balance at Dec. 31, 2022	36,749
Beginning balance, Shares at Dec. 31, 2022		101,636,649	15,999,173	101,636,649	15,999,173
Net (loss) income	16,132						16,132
Redeemable Noncontrolling Interest, Net income (loss)	(4,266)
Stock–based compensation expense	16,049					16,049
Issuance of common stock upon exercise of stock options	19					19
Issuance of common stock upon exercise of stock options, Shares				7,700
Issuance of common stock upon vesting of restricted stock units, Shares				959,935
Payment of withholding taxes on net share settlements of restricted stock units	(5,652)					(5,652)
Payment of withholding taxes on net share settlements of restricted stock units, Shares				(335,448)
Repurchase of common stock, Shares				(3,989,861)
Repurchase of common stock	(65,764)			$ (4)		(65,760)
Tax distribution to redeemable noncontrolling interest holders	(8)
Foreign currency translation adjustment	415							415
Ending balance at Mar. 31, 2023	695,808			$ 98	$ 16	357,748	339,175	(1,229)
Redeemable Noncontrolling Interest, Ending balance at Mar. 31, 2023	32,475
Ending balance, Shares at Mar. 31, 2023				98,278,975	15,999,173
Beginning balance at Dec. 31, 2022	734,609			$ 102	$ 16	413,092	323,043	(1,644)
Redeemable Noncontrolling Interest, Beginning balance at Dec. 31, 2022	36,749
Beginning balance, Shares at Dec. 31, 2022		101,636,649	15,999,173	101,636,649	15,999,173
Net (loss) income	32,545
Payment of withholding taxes on net share settlements of restricted stock units, Shares		(576,122)
Foreign currency translation adjustment	303
Ending balance at Jun. 30, 2023	700,854			$ 97	$ 16	346,494	355,588	(1,341)
Redeemable Noncontrolling Interest, Ending balance at Jun. 30, 2023	29,865
Ending balance, Shares at Jun. 30, 2023		97,426,273	15,999,173	97,426,273	15,999,173
Beginning balance at Mar. 31, 2023	695,808			$ 98	$ 16	357,748	339,175	(1,229)
Redeemable Noncontrolling Interest, Beginning balance at Mar. 31, 2023	32,475
Beginning balance, Shares at Mar. 31, 2023				98,278,975	15,999,173
Net (loss) income	16,413						16,413
Redeemable Noncontrolling Interest, Net income (loss)	(2,596)
Stock–based compensation expense	15,895					15,895
Issuance of common stock upon exercise of stock options	10					10
Issuance of common stock upon exercise of stock options, Shares				1,480
Issuance of common stock upon vesting of restricted stock units, Shares				697,879
Payment of withholding taxes on net share settlements of restricted stock units	(5,196)					(5,196)
Payment of withholding taxes on net share settlements of restricted stock units, Shares		(240,674)		(240,674)
Repurchase of common stock, Shares				(1,311,387)
Repurchase of common stock	(21,964)			$ 1		(21,963)
Tax distribution to redeemable noncontrolling interest holders	(14)
Foreign currency translation adjustment	(112)							(112)
Ending balance at Jun. 30, 2023	700,854			$ 97	$ 16	$ 346,494	$ 355,588	$ (1,341)
Redeemable Noncontrolling Interest, Ending balance at Jun. 30, 2023	$ 29,865
Ending balance, Shares at Jun. 30, 2023		97,426,273	15,999,173	97,426,273	15,999,173

Unaudited Condensed Consolida_7

Unaudited Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Operating Activities
Consolidated net income	$ 25,683	$ 36,899
Adjustments to reconcile consolidated net income to net cash provided by operating activities:
Depreciation and amortization	23,243	22,419
Gain on sale of property and equipment	(460)
Unrealized currency (gain) loss on foreign denominated transactions	(136)	354
Unrealized loss on short-term investments	21
Realized gain on short-term investments	(5)
Deferred taxes	(16,411)	(23,464)
(Recoveries) provision for doubtful accounts	(171)	699
Stock-based compensation expense	29,507	27,579
Amortization of deferred financing costs	258
Amortization of deferred contract costs	5,603	5,564
Impairment of long-lived assets	184
Changes in operating assets and liabilities:
Accounts receivable	13,241	(12,022)
Inventory	4,740	(2,028)
Prepaid expenses, prepaid income taxes, and other assets	3,454	(10,434)
Deferred contract costs	(9,738)	(5,746)
Accounts payable	4,140	8,168
Accrued expenses, accrued income taxes, and other liabilities	(4,091)	38,174
Deferred revenue	9,016	2,302
Lease obligations	7,603	(869)
Net cash provided by operating activities	95,681	87,595
Investing Activities
Purchases of property and equipment	(4,255)	(2,661)
Proceeds from sale of property and equipment	460
Capitalization of website development costs	(7,432)	(5,502)
Purchases of short-term investments	(95,506)
Maturities of short-term investments		60,000
Sales of short-term investments	5,000
Advance payments to customer, net of collections	(2,601)
Net cash (used in) provided by investing activities	(104,334)	51,837
Financing Activities
Proceeds from issuance of common stock upon exercise of stock options	29	705
Payment of withholding taxes on net share settlements of restricted stock units	(6,894)	(11,260)
Repurchase of common stock	(91,458)
Payment of finance lease obligations	(34)	(35)
Payment of tax distributions to redeemable noncontrolling interest holders	(38)	(12,691)
Change in gross advance payments received from third-party transaction processor	(2,674)	(2,363)
Net cash used in financing activities	(101,069)	(25,644)
Impact of foreign currency on cash, cash equivalents, and restricted cash	211	(912)
Net (decrease) increase in cash, cash equivalents, and restricted cash	(109,511)	112,876
Cash, cash equivalents, and restricted cash at beginning of period	484,132	248,280
Cash, cash equivalents, and restricted cash at end of period	374,621	361,156
Supplemental disclosure of cash flow information:
Cash paid for income taxes	36,303	41,160
Cash paid for operating lease liabilities	9,831	9,220
Cash paid for interest	279
Supplemental noncash disclosure of cash flow information:
Unpaid purchases of property and equipment, capitalized website development, capitalized internal-use software and capitalized hosting arrangements	4,509	362
Unpaid withholding taxes on net share settlement of restricted stock units	3,958
Unpaid repurchases of common stock	559
Capitalized stock-based compensation expense in website development and internal-use software costs and hosting arrangements	2,437	2,471
Obtaining a right-of-use asset in exchange for an operating lease liability	$ 144,556	5,307
Accretion of Redeemable Noncontrolling Interest to Redemption Value		111,620
Accrued Tax Distributions To Redeemable Noncontrolling Interest Holders		$ 3,638

Organization and Business Descr

Organization and Business Description	6 Months Ended
	Jun. 30, 2023
Accounting Policies [Abstract]
Organization and Business Description	1. Organization and Business Description CarGurus, Inc. (the "Company") is a multinational, online automotive platform for buying and selling vehicles that is building upon its industry-leading listings marketplace with both digital retail solutions and the CarOffer, LLC ("CarOffer") digital wholesale platform. The CarGurus platform gives consumers the confidence to buy and/or sell a vehicle either online or in-person, and it gives dealerships the power to accurately price, instantly acquire, effectively market, and quickly sell vehicles, all with a nationwide reach. The Company uses proprietary technology, search algorithms, and data analytics to bring trust, transparency, and competitive pricing to the automotive shopping experience. The Company is headquartered in Cambridge, Massachusetts and was incorporated in the State of Delaware on June 26, 2015 . The Company operates principally in the United States. In the United States, it also operates as independent brands the Autolist online marketplace, which it wholly owns, and the CarOffer digital wholesale platform, in which it holds a 51 % equity interest. In addition to the United States, the Company operates online marketplaces under the CarGurus brand in Canada and the United Kingdom. In the United Kingdom, it also operates as an independent brand the PistonHeads online marketplace, which it wholly owns. The Company has subsidiaries in the United States, Canada, Ireland, and the United Kingdom. Effective as of the fourth quarter of 2022 the Company revised its segment reporting from one reportable segment to two reportable segments – U.S. Marketplace and Digital Wholesale. See Note 12 of these Unaudited Condensed Consolidated Financial Statements (as defined below) for further segment reporting and geographic information. The Company is subject to a number of risks and uncertainties common to companies in its and similar industries and stages of development including, but not limited to, rapid technological changes, competition from substitute products and services from larger companies, management of international activities, protection of proprietary rights, patent litigation, and dependence on key individuals.

Summary of Significant Accounti

Summary of Significant Accounting Policies	6 Months Ended
	Jun. 30, 2023
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Basis of Presentation The accompanying interim condensed consolidated financial statements are unaudited (the “Unaudited Condensed Consolidated Financial Statements”). The Unaudited Condensed Consolidated Financial Statements and related disclosures have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”). Any reference in these notes to applicable guidance is meant to refer to GAAP as found in the Accounting Standards Codification (“ASC”) and Accounting Standards Update of the Financial Accounting Standards Board (“FASB”). The Unaudited Condensed Consolidated Financial Statements have also been prepared pursuant to the rules and regulations of the U.S. Securities and Exchange Commission (“SEC”). Accordingly, certain information and footnote disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations. The Unaudited Condensed Consolidated Financial Statements reflect all adjustments, consisting of only normal recurring adjustments, necessary for the fair presentation of the Company’s financial position as of June 30, 2023 and December 31, 2022, results of operations, comprehensive income, and changes in stockholders’ equity for the three months ended June 30, 2023 and 2022 and for the six months ended June 30, 2023 and 2022, and cash flows for the six months ended June 30, 2023 and 2022. These interim period results are not necessarily indicative of the results to be expected for any other interim period or the full year. The Unaudited Condensed Consolidated Financial Statements should be read in conjunction with the Company’s audited consolidated financial statements and the notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2022, filed with the SEC on March 1, 2023 (the “Annual Report”). While the Company disclosed interest income within other income (expense), net in the Unaudited Condensed Consolidated Income Statements in the Company's Quarterly Report on Form 10-Q for the quarter ended June 30, 2022, filed with the SEC on August 8, 2022, the accompanying Unaudited Condensed Consolidated Income Statements for the quarter ended June 30, 2022 present interest income separately from other income (expense), net to conform to the current year presentation, as interest income met the threshold for separate disclosure. Principles of Consolidation The Unaudited Condensed Consolidated Financial Statements include the accounts of the Company and its subsidiaries. All intercompany balances and transactions have been eliminated in consolidation. Subsequent Event Considerations The Company considers events or transactions that occur after the balance sheet date but prior to the issuance of the financial statements to provide additional evidence for certain estimates or to identify matters that require additional disclosure. The Company has evaluated all subsequent events and determined that there are no material recognized or unrecognized subsequent events requiring disclosure. Use of Estimates The preparation of the Unaudited Condensed Consolidated Financial Statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, and the disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenue and expenses during the reporting period. Although the Company regularly assesses these estimates, actual results could differ materially from these estimates. The Company bases its estimates on historical experience and various other assumptions that it believes to be reasonable under the circumstances. Actual results may differ from management’s estimates if these results differ from historical experience, or other assumptions do not turn out to be substantially accurate, even if such assumptions are reasonable when made. Changes in estimates are recognized in the period in which they become known. Critical estimates relied upon in preparing the Unaudited Condensed Consolidated Financial Statements include the determination of sales allowance and variable consideration in the Company’s revenue recognition, allowance for doubtful accounts, the impairment of long-lived assets, the capitalization of product, technology, and development costs for website development, internal-use software and hosting arrangements, the valuation of acquired assets and liabilities, the valuation and recoverability of intangible assets and goodwill, the valuation of redeemable noncontrolling interest, the recoverability of the Company’s net deferred tax assets and related valuation allowance, the valuation of inventory, and the valuation of equity and liability-classified compensation awards. Accordingly, the Company considers these to be its critical accounting estimates, and believes that of the Company’s significant accounting policies, these involve the greatest degree of judgment and complexity. Concentration of Credit Risk The Company has no significant off-balance sheet risk, such as foreign exchange contracts, option contracts, or other foreign hedging arrangements. Financial instruments that potentially expose the Company to concentrations of credit risk consist primarily of cash, cash equivalents, short-term investments, trade accounts receivable, and other receivables. The Company maintains its cash, cash equivalents, and short-term investments principally with accredited financial institutions of high credit standing. Although the Company deposits its cash, cash equivalents, and short-term investments with multiple financial institutions, its deposits with each such financial institution exceed governmental insured limits. The Company routinely assesses the creditworthiness of its customers and does not require collateral. The Company generally has not experienced any material losses related to receivables from individual customers or groups of customers. The majority of the Company's accounts receivable results from wholesale and product revenue transactions. The Company has had no material losses related to wholesale and product receivables as the third-party transaction processor does not release the title to the vehicle until successfully collecting funds from the buying dealer. Titling is handled by the Company's third-party transaction processor and titles are held in escrow until it collects funds from the buying dealer (i.e., title is legally transferred from the selling party to the buying party upon signing of bill of sale, but title is held in escrow by the third-party transaction processor until payment is received). Due to these factors, no additional credit risk beyond amounts provided for collection losses is believed by management to be probable in the Company’s accounts receivable and other receivables. As of June 30, 2023 , one customer accounted for 11 % of net accounts receivable and other receivables. As of December 31, 2022 , one customer accounted for 13 % of net accounts receivable. The remainder of the accounts receivable was dispersed among more than 1,000 custo mers. The customers who accounted for greater than 10 % of net accounts receivable are related to wholesale and product receivables. The collection risk associated with these customers is mitigated because, as discussed above, the third-party transaction processor does not release the title on vehicles until funds are successfully collected. Furthermore, there is no significant credit risk with respect to accounts receivable because, other than the receivables associated with these customers, credit risk with respect to accounts receivable is dispersed due to the large number of customers. For the three and six months ended June 30, 2023 , no individual customer accounted for more than 10% of total revenue. For the three months ended June 30, 2022 , two customers each accounted for 11 % of total revenue due to the continued growth of the CarOffer business. For the six months ended June 30, 2022 , no individual customer accounted for more than 10% of total revenue. The Company is exposed to credit losses primarily through its trade accounts receivable, which includes receivables in transit, net of payables due, from a third-party transaction processor. The third-party transaction processor collects customer payments on the Company's behalf and remits them to the Company. Customer payments received by the third-party transaction processor, but not remitted to the Company as of period end are deemed to be receivables in transit, net of payables due. Additionally, the third-party transaction processor provides payments in advance for certain selling dealers. If the third-party transaction processor does not receive buying dealer payments associated with the transaction paid in advance, the Company would guarantee losses incurred by the third-party transaction processor and the balance would be deducted from future remittances to the Company. To date, losses associated with these guarantees have not been material. The Company offsets trade accounts receivables in transit, net of payables due, from the third-party transaction processor with payments received in advance from the third-party transaction processor as it has the right of offset. At any point in time, the Company could have amounts due from the third-party transaction processor for funds the third-party transaction processor has collected from buying dealers and has not yet remitted to the Company (i.e., receivables in transit, net of payables due), as well as amounts paid by the third-party transaction processor to the Company in advance of collecting payments from buying dealers (i.e., payments received in advance). Therefore, as the Company has the right to offset, the Company can either have a net receivable balance due from the third-party transaction processor which is recognized within accounts receivable, net in the Unaudited Condensed Consolidated Balance Sheets, or the Company can have a net liability which is recognized within accrued expenses, accrued income taxes, and other current liabilities in the Unaudited Condensed Consolidated Balance Sheets if the advance payments exceed the receivable position from the third-party transaction processor as of the balance sheet date. Payments received in advance from the third-party transaction processor are presented as cash flows from financing activities in the Unaudited Condensed Consolidated Statements of Cash Flows. As of June 30, 2023, trade accounts receivable from receivables in transit, net of payables due, from the third-party transaction processor was $ 2,427 , offset by payments received in advance of $ 3,816 , which resulted in a net payable of $ 1,389 recognized within accrued expenses, accrued income taxes, and other current liabilities in the Unaudited Condensed Consolidated Balance Sheets. As of December 31, 2022, trade accounts receivable from receivables in transit, net of payables due, from the third-party transaction processor was $ 7,122 , offset by payments received in advance of $ 6,490 , which resulted in a net receivable of $ 632 recognized within accounts receivable, net in the Unaudited Condensed Consolidated Balance Sheets. As of June 30, 2023 and December 31, 2022, $ 7,655 and $ 7,150 , respectively , was included in net accounts receivable, representing unbilled accounts receivable relating primarily to advertising customers invoiced in the period subsequent to services rendered. Significant Accounting Policies The Unaudited Condensed Consolidated Financial Statements reflect the application of certain significant accounting policies as described below and elsewhere in these notes to the Unaudited Condensed Consolidated Financial Statements. As of June 30, 2023 , there have been no material changes in the Company’s significant accounting policies, which are detailed in the Annual Report, other than those described below. Cash, Cash Equivalents, and Investments As of June 30, 2023 and December 31, 2022, cash and cash equivalents primarily consist of cash on deposit with banks, amounts held in interest-bearing money market accounts, and investments with original maturities of 90 days or less. Cash equivalents are carried at cost, which approximates their fair market value. The Company’s investment policy, which was approved by the Audit Committee of the Company’s Board of Directors (the “Board”), permits investments in fixed income securities, including U.S. government and agency securities, non‑U.S. government securities, money market instruments, commercial paper, certificates of deposit, corporate bonds, and asset‑backed securities. The Company considers all highly liquid investments with an original maturity of 90 days or less at the date of purchase to be cash equivalents. Investments not classified as cash equivalents with maturities less than one year from the balance sheet date are classified as short‑term investments, while investments with maturities in excess of one year from the balance sheet date are classified as long‑term investments. Management determines the appropriate classification of investments at the time of purchase, and re‑evaluates such determination at each balance sheet date. Investments in equity securities with readily determinable fair values are recognized at fair value based on quoted market prices within investments in the Unaudited Condensed Consolidated Balance Sheets. Investments in held-to-maturity debt securities are recognized at amortized cost within investments in the Unaudited Condensed Consolidated Balance Sheets. The Company adjusts the cost of investments in held-to-maturity debt securities for amortization of premiums and accretion of discounts to maturity, if any. Investments in trading and available-for-sale debt securities are recognized at fair value within investments in the Unaudited Condensed Consolidated Balance Sheets. Purchases of equity securities and debt securities are recognized within investing activities in the Unaudited Condensed Consolidated Statements of Cash Flows. Dividend income from equity securities is recognized within interest income in the Unaudited Condensed Consolidated Income Statements. Reinvested proceeds from dividend income are recognized within purchases of investments in investing activities in the Unaudited Condensed Consolidated Statements of Cash Flows. The revaluation of equity securities and debt securities results in an unrealized gain or loss. Unrealized gains or losses on equity securities and trading debt securities are recognized within other income (expense), net in the Unaudited Condensed Consolidated Income Statements and backed out of operating activities in the Unaudited Condensed Consolidated Statements of Cash Flows. Unrealized gains or losses on available-for-sale debt securities are recognized within other comprehensive income in the Unaudited Condensed Consolidated Statements of Comprehensive Income. Interest on held-to-maturity debt securities is recognized within interest income in the Unaudited Condensed Consolidated Income Statements. Proceeds from sale of equity securities and debt securities are recognized within investing activities in the Unaudited Condensed Consolidated Statements of Cash Flows. Realized gains and losses on sale of equity securities and debt securities are recognized within other (expense) income, net in the Unaudited Condensed Consolidated Income Statements, backed out of operating activities in the Unaudited Condensed Consolidated Cash Flows, and recognized within proceeds from sale of equity securities and debt securities in investing activities in the Unaudited Condensed Consolidated Statements of Cash Flows. Debt securities are reviewed for other‑than‑temporary impairment whenever the fair value of an investment is less than the amortized cost and evidence indicates that an investment’s carrying amount is not recoverable within a reasonable period of time. Other‑than‑temporary impairments of debt securities are recognized within other income (expense), net in the Unaudited Condensed Consolidated Income Statements if the Company has experienced a credit loss or if it is more likely than not that the Company will be required to sell the investment before recovery of the amortized cost basis. Evidence considered in this assessment includes reasons for the impairment, compliance with the Company’s investment policy, the severity and duration of the impairment, and changes in value subsequent to the end of the period. As of June 30, 2023, the Company held short-term investments in equity securities. As of December 31, 2022, the Company held no investments. Recent Accounting Pronouncements Not Yet Adopted From time to time, new accounting pronouncements are issued by the FASB or other standard setting bodies and adopted by the Company on or prior to the specified effective date. Unless otherwise discussed, the Company believes that the impact of recently issued standards that are not yet effective will not have a material impact on its financial position or results of operations upon adoption. As of June 30, 2023 , there are no new material accounting pronouncements that the Company is considering adopting.

Revenue Recognition

Revenue Recognition	6 Months Ended
	Jun. 30, 2023
Revenue from Contract with Customer [Abstract]
Revenue Recognition	3. Revenue Recognition The following table summarizes revenue from contracts with customers by services and products for the three months ended June 30, 2023 and 2022 and for the six months ended June 30, 2023 and 2022: Three Months Ended Six Months Ended 2023 2022 2023 2022 Marketplace $ 170,950 $ 163,926 $ 338,077 $ 327,215 Dealer-to-Dealer 32,950 97,064 61,655 202,555 Instant Max Cash Offer 35,837 250,239 71,968 412,067 Total $ 239,737 $ 511,229 $ 471,700 $ 941,837 The Company provides disaggregation of revenue by services and products, by income statement presentation, by segment, and by geographic region. Revenue by services and products is disaggregated by (i) marketplace services, (ii) Dealer-to-Dealer services and products, and (iii) Instant Max Cash Offer ("IMCO") services and products as disclosed above. Revenue by income statement presentation is disaggregated by (i) marketplace, (ii) wholesale, and (iii) product revenue sources as disclosed in the Unaudited Condensed Consolidated Income Statements. Marketplace services are included within marketplace revenue in the Unaudited Condensed Consolidated Income Statements. Dealer-to-Dealer and IMCO services and products are included within both wholesale revenue and product revenue in the Unaudited Condensed Consolidated Income Statements. Revenue by segment is disaggregated by (i) U.S. Marketplace and (ii) Digital Wholesale segments as disclosed in Note 12 of these Unaudited Condensed Consolidated Financial Statements. Marketplace services are included in the U.S. Marketplace segment and in the Other category of segment reporting. Dealer-to-Dealer and IMCO services and products are included in the Digital Wholesale segment. Revenue by geographic region is disaggregated by (i) United States and (ii) International regions as disclosed in Note 12 of these Unaudited Condensed Consolidated Financial Statements. Marketplace services are provided in the United States and International regions. Dealer-to-Dealer and IMCO services and products are provided in the United States region. The Company believes these categories best depict how the nature, amount, timing, and uncertainty of revenue and cash flows are affected by economic factors. ASC Topic 606, Revenue from Contracts with Customer s (“ASC 606”), requires that the Company disclose the aggregate amount of transaction price that is allocated to performance obligations that have not yet been satisfied as of the relevant quarter end. For contracts with an original expected duration greater than one year, the aggregate amount of the transaction price allocated to the performance obligations that were unsatisfied as of June 30, 2023 was approximately $ 18.5 million, which the Company expects to recognize over the next twelve months. For contracts with an original expected duration of one year or less, the Company has applied the practical expedient available under ASC 606 to not disclose the amount of transaction price allocated to unsatisfied performance obligations as of June 30, 2023. For performance obligations not satisfied as of June 30, 2023, and to which this expedient applies, the nature of the performance obligations, the variable consideration, and any consideration from contracts with customers not included in the transaction price is consistent with performance obligations satisfied as of June 30, 2023. For the three months ended June 30, 2023 and 2022, revenue recognized from amounts included in deferred revenue at the beginning of the period was $ 20,808 and $ 12,776 , respectively. For the six months ended June 30, 2023 and 2022, revenue recognized from amounts included in deferred revenue at the beginning of the period was $ 12,249 and $ 12,784 , respectively.

Fair Value of Financial Instrum

Fair Value of Financial Instruments	6 Months Ended
	Jun. 30, 2023
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments	4. Fair Value of Financial Instruments As of June 30, 2023 and December 31, 2022, assets measured at fair value on a recurring basis consist of the following: As of June 30, 2023 Quoted Prices Significant Other Significant Total Cash equivalents: Mutual funds $ 204,560 $ — $ — $ 204,560 Short-term investments: Mutual funds 90,490 — — 90,490 Total $ 295,050 $ — $ — $ 295,050 As of December 31, 2022 Quoted Prices Significant Other Significant Total Cash equivalents: Mutual funds $ 175,486 $ — $ — $ 175,486 Total $ 175,486 $ — $ — $ 175,486 For the three and six months ended June 30, 2023, unrealized gain on investments in equity securities were immaterial. As of December 31, 2022, the Company did no t have any investments.

Property and Equipment, Net

Property and Equipment, Net	6 Months Ended
	Jun. 30, 2023
Property, Plant and Equipment [Abstract]
Property and Equipment, Net	5. Property and Equipment, Net As of June 30, 2023 and December 31, 2022, property and equipment, net consist of the following: As of As of Capitalized equipment $ 1,297 $ 7,877 Capitalized internal-use software 9,547 7,429 Capitalized website development 45,643 36,369 Furniture and fixtures 8,904 8,615 Leasehold improvements 24,322 24,225 Construction in progress 8,641 4,161 Finance lease right-of-use assets 354 420 98,708 89,096 Less accumulated depreciation and amortization ( 50,465 ) ( 48,968 ) Total $ 48,243 $ 40,128 For the three months ended June 30, 2023 and 2022 and for the six months ended June 30, 2023 and 2022, depreciation and amortization expense, excluding amortization of intangible assets, amortization of capitalized hosting arrangements, and write-offs, was $ 4,160 , $ 3,562 , $ 8,202 , and $ 7,042 , respectively. For the three months ended June 30, 2023, the Company wrote off $ 9 of U.S. Marketplace segment capitalized website development costs within marketplace cost of revenue in the Unaudited Condensed Consolidated Income Statements, related to certain developed technology in which the Company has decided to cease investment. For the six months ended June 30, 2023, the Company wrote off $ 184 of Digital Wholesale and U.S. Marketplace capitalized website development costs within wholesale and marketplace cost of revenue, respectively, in the Unaudited Condensed Consolidated Income Statements related to certain developed technology in which the Company has decided to cease investment. For the three and six months ended June 30, 2022 , the Company did no t have any write-offs. During the six months ended June 30, 2023, capitalized equipment decreased $ 6,580 due primarily to the disposal of the data center assets as a result of the Company's migration onto a cloud-based hosting platform. During the six months ended June 30, 2023, capitalized website development costs increased $ 9,274 due to continued net investment in the Company's product offerings. During the six months ended June 30, 2023, construction in progress costs increased $ 4,480 due to the buildout of the Company's future headquarters at 1001 Boylston Street, as discussed in Note 8 to these Unaudited Condensed Consolidated Financial Statements.

Accrued Expenses, Accrued Incom

Accrued Expenses, Accrued Income Taxes and Other Current Liabilities	6 Months Ended
	Jun. 30, 2023
Payables and Accruals [Abstract]
Accrued Expenses, Accrued Income Taxes and Other Current Liabilities	6. Accrued Expenses, Accrued Income Taxes, and Other Current Liabilities As of June 30, 2023 and December 31, 2022, accrued expenses, accrued income taxes, and other current liabilities consist of the following: As of As of Accrued bonus $ 11,874 $ 11,007 Other accrued expenses, accrued income taxes, and other current liabilities 24,493 28,186 Total $ 36,367 $ 39,193

Debt

Debt	6 Months Ended
	Jun. 30, 2023
Debt Disclosure [Abstract]
Debt	7. Debt As of June 30, 2023 and December 31, 2022 , the Company had no long-term debt outstanding. Revolving Credit Facility On September 26, 2022, the Company entered into a Credit Agreement (the “Credit Agreement”) by and among the Company, PNC Bank, National Association, as administrative agent and collateral agent and an L/C Issuer (as defined in the Credit Agreement), and the other lenders, L/C Issuers, and parties thereto from time to time. The Credit Agreement consists of a revolving credit facility (the “2022 Revolver” ), which allows the Company to borrow up to $ 400.0 million, $ 50.0 million of which may be comprised of a letter of credit sub-facility (the "2022 Revolver Sub-facility"). The borrowing capacity under the Credit Agreement may be increased in accordance with the terms and subject to the adjustments as set forth in the Credit Agreement. For example, the borrowing capacity may be increased by an amount up to the greater of $ 250.0 million or 100 % of Four Quarter Consolidated EBITDA (as defined in the Credit Agreement) if certain criteria are met and subject to certain restrictions. Any such increase requires lender approval. Proceeds of any borrowings may be used for general corporate purposes. The 2022 Revolver is scheduled to mature on September 26, 2027 . The applicable interest rate is, at the Company's option, based on a number of different benchmark rates and applicable spreads, based on the ratio of the outstanding principal amount of the Company’s secured indebtedness to the trailing four quarters of consolidated EBITDA (as determined under the Credit Agreement, the “Consolidated Secured Net Leverage Ratio”). The Credit Agreement also requires the Company to pay a commitment fee to the lenders with respect of the unutilized revolving commitments at a rate ranging from 0.125 % to 0.175 % per annum based on the Consolidated Secured Net Leverage Ratio, as determined on a quarterly basis. The 2022 Revolver is secured by a first priority lien on substantially all tangible and intangible property of the Company and its subsidiary, AutoList, Inc., as well as any future guarantors, and pledges of the equity of CarOffer and certain wholly-owned subsidiaries, in each case subject to certain exceptions, limitations, and exclusions from the collateral. The Credit Agreement includes customary events of default and requires the Company to comply with customary affirmative and negative covenants, including a financial covenant requiring that the Company not exceed certain Consolidated Secured Net Leverage Ratio ranges at the end of each fiscal quarter. The Company was in compliance with all covenants as of June 30, 2023. As of June 30, 2023 , there were no borrowings and $ 742 in letters of credit outstanding, which reduces the borrowing capacity under the 2022 Revolver to $ 399,258 . As of December 31, 2022 , there were no borrowings and no letters of credit outstanding under the 2022 Revolver. As of June 30, 2023, deferred financing costs were $ 2,184 . As of December 31, 2022, deferred financing costs were $ 2,442 . For the three and six months ended June 30, 2023, amortization expense associated with deferred financing costs were $ 129 and $ 258 , respectively. For the three and six months ended June 30, 2022 , the Company did no t recognize any amortization expense associated with deferred financing costs. As of June 30, 2023 and December 31, 2022 , commitment fees under the 2022 Revolver were immaterial.

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2023
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	8. Commitments and Contingencies Contractual Obligations and Commitments As of June 30, 2023, all of the Company’s property, equipment, and externally sourced internal-use software have been purchased with cash with the exception of amounts related to unpaid property and equipment, capitalized website development, capitalized internal-use software and capitalized hosting arrangements, and amounts related to obligations under finance leases as disclosed in the Unaudited Condensed Consolidated Statements of Cash Flows. In connection with the 1001 Boylston Street lease, the Company expects to spend approximately $ 69,815 , net of tenant reimbursements. As of June 30, 2023, the Company has incurred $ 8,835 in expenses, of which $ 8,641 was capitalized. The Company has also signed $ 2,526 in contract commitments, which have not yet been incurred. The Company has no other material long-term purchase obligations outstanding with any vendors or third-parties. Leases The Company’s lease obligations consist substantially of various leases for office space in: Boston, Massachusetts; Cambridge, Massachusetts; San Francisco, California; Addison, Texas; and Dublin, Ireland. As of June 30, 2023, there were no material changes in the Company’s leases from those disclosed in the Annual Report, other than those described below. New Material Leases The Company’s oper ating lease agreement in Boston, Massachusetts for 225,428 square feet at 1001 Boylston Street (the "1001 Boylston Street Lease") commenced on February 3, 2023 ("Delivery Date") as the Company has been granted access to begin its build out. The “Commencement Date” of the lease term is the earlier to occur of (i) the date that is 12 months following the Delivery Date and (ii) the date that the Company first occupies the premises for the normal conduct of business for the Permitted Use (as defined in the 1001 Boylston Street Lease). The initial term will commence on the Commencement Date and expire on the date that is 180 full calendar months after the Commencement Date (plus the partial month, if any, immediately following the Commencement Date). The 1001 Boylston Street Lease provides for the option to terminate early under certain circumstances and contains options to extend the lease term for two additional periods of five years. The 1001 Boylston Street Lease provides for annual rent increases through the term of the lease, leasehold improvement incentives, and variable payments related to operating expenses, management fees, taxes, utilities, insurance, and maintenance expenses. The 1001 Boylston Street Lease also contains both lease and non-lease components. Non-lease components relate to operating expenses, parking, utilities, and maintenance expenses. The Company expects to move into the office space in 2024. Lease Commitments As of June 30, 2023, future minimum lease payments for all leases are as follows: Year Ending December 31, Operating Remainder of 2023 $ 5,974 2024 15,922 2025 18,592 2026 22,334 2027 22,742 Thereafter 231,155 Total lease payments $ 316,719 Less imputed interest ( 109,665 ) Total $ 207,054 The table above does not include leases signed but not yet commenced as of June 30, 2023. As of June 30, 2023, total estimated future minimum lease payments for leases signed but not yet commenced are estimated to be $ 1,093 . The lease is expected to commence in the current fiscal year with lease terms of approximately two years . For the three months ended June 30, 2023 and 2022 and for the six months ended June 30, 2023 and 2022, the Company recognized $ 9,103 , $ 4,176 , $ 16,547 , and $ 8,228 of lease costs, respectively. As of June 30, 2023, the weighted average remaining lease term was 13.2 years, and the weighted average discount rate was 5.7 % . As the Company's leases do not provide an implicit rate, the Company uses an estimated incremental borrowing rate based on the information available at lease commencement in determining the present value of lease payments. The Company estimated the incremental borrowing rate based on the rate of interest the Company would have to pay to borrow a similar amount on a collateralized basis over a similar term. The Company has no historical debt transactions and a collateralized rate is estimated based on a group of peer companies. The Company used the incremental borrowing rate on January 1, 2019 for leases that commenced prior to that date. Sublease Income As of June 30, 2023, future minimum sublease income payments are as follows: Year Ending December 31, Sublease Remainder of 2023 $ 1,120 2024 1,951 2025 1,023 2026 — 2027 — Thereafter — Total $ 4,094 Restricted Cash The 1001 Boylston Street Lease and the Company’s leases in Cambridge, Massachusetts and San Francisco, California have associated letters of credit. As of December 31, 2022, all letters of credit were collateralized by cash, which was recognized as restricted cash in the Unaudited Condensed Consolidated Balance Sheets. As of June 30, 2023, $ 742 of letters of credit were included under the 2022 Revolver Sub-facility, as the Company canceled two letters of credit associated with the San Francisco and the Cambridge (55 Cambridge Parkway) leases and reissued these letters of credit under the 2022 Revolver Sub-facility. As of June 30, 2023, $ 8,885 of letters of credit associated with the 1001 Boylston Street Lease remained collateralized by cash, which was recognized as restricted cash in the Unaudited Condensed Consolidated Balance Sheets. The Company expects to cancel the letter of credit associated with the 1001 Boylston Street Lease and reissue a new letter of credit under the 2022 Revolver Sub-facility in the next 12 months. As of June 30, 2023 and December 31, 2022, restricted cash was $ 11,561 and $ 14,615 , respectively, and primarily related to cash held at a financial institution in an interest‑bearing cash account as collateral for the letters of credit related to the contractual provisions for the Company’s building lease and pass-through payments from customers related to the Company’s wholesale business. As of December 31, 2022, portions of restricted cash were classified as a short-term asset and long‑term asset, as disclosed in the Unaudited Condensed Consolidated Balance Sheets. During the six months ended June 30, 2023, the Company reclassified $ 9,378 of letters of credit from a long-term asset to a short-term asset as the Company expects to cancel and reissue the remaining letters of credit, outstanding as of December 31, 2022, under the 2022 Revolver Sub-facility in the next 12 months. Of the letters of credit outstanding as of December 31, 2022, the Company canceled a letter of credit associated with the Cambridge (2 Canal Park) lease, however, the cash was recognized as restricted cash as of March 31, 2023, until it was released from the bank. During the three months ended June 30, 2023, the Company released the cash associated with the Cambridge (2 Canal Park) lease. As of June 30, 2023, all restricted cash was classified as a short-term asset, as disclosed in the Unaudited Condensed Consolidated Balance Sheets. Acquisitions On January 14, 2021, the Company completed the acquisition of a 51 % interest in CarOffer , an automated instant vehicle trade platform based in Addison, Texas, with the option to acquire portions of the remaining equity in the future. During the year ended December 31, 2022, the Company determined not to exercise its call right to acquire up to an additional 25 % of the fully diluted capitalization of CarOffer. In the second half of 2024, the Company will have a call right to acquire all, and not less than all, of the remaining equity interests in CarOffer and the representative of the holders of the remaining equity will have a put right to sell to the Company all, and not less than all, of the remaining equity interests in CarOffer. D etails of this acquisition are more fully described in Note 2 to the consolidated financial statements contained within the Annual Report. Legal Matters From time to time the Company may become involved in legal proceedings or be subject to claims arising in the ordinary course of its business. The Company recognizes a liability when it believes that it is both probable that a liability has been incurred and the amount of loss can be reasonably estimated. Judgment is required to determine both the probability of having incurred a liability and the estimated amount of the liability. The Company is not presently subject to any pending or threatened litigation that it believes, if determined adversely to the Company, individually, or taken together, would reasonably be expected to have a material adverse effect on its business or financial results. However, litigation is inherently unpredictable and the future outcome of legal proceedings and other contingencies may be unexpected or differ from the Company’s estimated liabilities, which could have a material adverse effect on the Company’s future financial results. Guarantees and Indemnification Obligations In the ordinary course of business, the Company enters into agreements with its customers, partners, and service providers that include commercial provisions with respect to licensing, infringement, guarantees, indemnification, and other common provisions. The Company provides certain guarantees to dealers through products such as its 45 -Day Guarantee and OfferGuard service offerings on the CarOffer platform, which are accounted for under ASC Topic 460, Guarantees . 45-Day Guarantee is an arrangement through which a selling dealer lists a car on the CarOffer platform, and the Company provides an offer to purchase the vehicle listed at a specified price at any time over a 45-day period. This provides the seller with a put option, where they have the right, but not the obligation, to require the Company to purchase the vehicle during this window. OfferGuard is an arrangement through which a buying dealer purchases a car on the CarOffer platform, and the Company provides an offer to purchase the vehicle at a specified price between days 1 and 3, and days 42 and 45 if the dealer is not able to sell the vehicle after 42 days. A guarantee liability is initially measured using the amount of consideration received from the dealer for the purchase of the guarantee. The initial liability is released, and guarantee income is recognized, upon the earliest of the following: the vehicle sells during the guarantee period, the seller exercises its put option during the guarantee period, or the option expires unexercised at the end of the guarantee period. Guarantee income is recognized within wholesale revenue in the Unaudited Condensed Consolidated Income Statements . Gains and losses resulting from dealers' exercise of guarantees are recognized within wholesale cost of revenue in the Unaudited Condensed Consolidated Income Statements. When it is probable and reasonably estimable that the Company will incur a loss on a vehicle that it is required to purchase, a liability and a corresponding charge to wholesale cost of revenue is recognized for the amount of the loss in the Unaudited Condensed Consolidated Balance Sheets and Unaudited Condensed Consolidated Income Statements. For the three months ended June 30, 2023 and 2022 and for the six months ended June 30, 2023 and 2022, income for guarantees purchased by dealers was $ 546 , $ 2,292 , $ 1,160 , and $ 5,595 , respectively. For the three months ended June 30, 2023 and 2022 and for the six months ended June 30, 2023 and 2022, the loss, net of gains, recognized within cost of revenue in the Unaudited Condensed Consolidated Income Statements resulting from dealers' exercise of guarantees was $ 164 , $ 259 , $ 89 , and $ 2,083 respectively. As of June 30, 2023, the maximum potential amount of future payments that the Company could be required to make under these guarantees was $ 19,367 . Of the maximum potential amount of future payments, the losses that were probable were immaterial. As such, as of June 30, 2023, the Company had immaterial contingent loss liabilities. As of December 31, 2022, the maximum potential amount of future payments that the Company could be required to make under these guarantees was $ 31,056 . Of the maximum potential amount of future payments, the losses that were probable were immaterial. As such, as of December 31, 2022 , the Company had immaterial contingent loss liabilities.

Stock-based Compensation and Co

Stock-based Compensation and Common Stock Share Repurchases	6 Months Ended
	Jun. 30, 2023
Share-Based Payment Arrangement [Abstract]
Stock-based Compensation and Common Stock Share Repurchases	9. Stock-based Comp ensation and Common Stock Share Repurchases Stock-based Compensation Expense For the three months ended June 30, 2023 and 2022 and for the six months ended June 30, 2023 and 2022, stock-based compensation expense by award type and where the stock-based compensation expense was recognized in the Unaudited Condensed Consolidated Income Statements is as follows: Three Months Ended Six Months Ended 2023 2022 2023 2022 Options $ 590 $ 646 $ 1,204 $ 1,290 Restricted Stock Units 14,012 12,786 28,375 26,289 CO Incentive Units and Subject Units 1,225 13,025 1,225 26,720 Total $ 15,827 $ 26,457 $ 30,804 $ 54,299 The decrease of $ 11,800 for the three months ended June 30, 2023 and the decrease of $ 25,495 for the six months ended June 30, 2023 compared to the three months ended June 30, 2022 and six months ended June 30, 2022, respectively, in CO Incentive Units and Subject Units (as each term is defined in Note 2 to the consolidated financial statements contained within the Annual Report) stock-based compensation expense was due to a decrease in the valuation of the awards following the mark to market valuation adjustments. Three Months Ended Six Months Ended 2023 2022 2023 2022 Cost of revenue $ 185 $ 69 $ 328 $ 205 Sales and marketing expense 2,872 4,086 5,956 8,069 Product, technology, and development expense 6,034 6,151 12,323 12,519 General and administrative expense 6,736 16,151 12,197 33,506 Total $ 15,827 $ 26,457 $ 30,804 $ 54,299 For the three months ended June 30, 2023 and 2022 and for the six months ended June 30, 2023 and 2022, stock-based compensation expense excluded $ 1,292 , $ 1,265 , $ 2,437 , and $ 2,471 , respectively, of capitalized website development costs, capitalized internal-use software costs, and capitalized hosting arrangements. During the three months ended June 30, 2023 and 2022 and the six months ended June 30, 2023 and 2022, the Company withheld 240,674 , 147,533 , 576,122 , and 303,269 shares of Class A common stock, respectively, to satisfy employee tax withholding requirements for net share settlements of restricted stock units ("RSUs"). The shares withheld return to the authorized, but unissued pool under the Company's Omnibus Incentive Compensation Plan and can be reissued by the Company. For the three months ended June 30, 2023, total payments to satisfy employee tax withholding requirements for net share settlements of RSUs were $ 5,196 of which $ 4,828 was paid and $ 368 was unpaid. For the six months ended June 30, 2023, total payments to satisfy employee tax withholding requirements for net share settlements of RSUs were $ 10,852 , of which $ 6,894 was paid and reflected as a financing activity in the Unaudited Condensed Consolidated Statements of Cash Flows and $ 3,958 was unpaid and reflected as a supplemental noncash disclosure in the Unaudited Condensed Consolidated Statements of Cash Flows. For the three and six months ended June 30, 2022, total payments to satisfy employee tax withholding requirements for net share settlements of RSUs were $ 5,830 and $ 11,260 , respectively, all of which were paid and reflected as a financing activity in the Unaudited Condensed Consolidated Statements of Cash Flows. Common Stock Share Repurchases On December 8, 2022, the Company announced that the Board authorized a new share repurchase program (the “Share Repurchase Program”), pursuant to which the Company may, from time to time, purchase shares of its Class A common stock for an aggregate purchase price not to exceed $ 250.0 million. Share repurchases under the Share Repurchase Program may be made through a variety of methods, including but not limited to open market purchases, privately negotiated transactions, and transactions that may be effected pursuant to one or more plans under Rule 10b5-1 and/or Rule 10b-18 of the Securities Exchange Act of 1934, as amended. The Share Repurchase Program does not obligate the Company to repurchase any minimum dollar amount or number of shares. The Share Repurchase Program has an expiration date of December 31, 2023, and prior to its expiration may be modified, suspended, or discontinued by the Board at any time without prior notice. All repurchased shares under the Share Repurchase Program will be retired. The Company expects to fund any share repurchases through cash on hand and cash generated from operations. During the three months ended June 30, 2023, the Company repurchased and retired 1,311,387 shares for $ 21,968 , exclusive of commissions and excise tax, at an average cost of $ 16.75 per share, under the Share Repurchase Program. During the six months ended June 30, 2023, the Company repurchased and retired 5,301,248 shares for $ 87,119 , exclusive of commissions and excise tax, at an average cost of $ 16.43 per share, under the Share Repurchase Program. As of June 30, 2023, the Company had remaining authorization to purchase up to $ 144,190 of the Company's Class A common stock under the Share Repurchase Program.

Earnings Per Share

Earnings Per Share	6 Months Ended
	Jun. 30, 2023
Earnings Per Share [Abstract]
Earnings Per Share	10. Earnings Per Share The Company has two classes of common stock authorized: Class A common stock and Class B common stock. The rights of the holders of Class A and Class B common stock are identical, except with respect to voting and conversion. Each share of Class A common stock is entitled to one vote per share and each share of Class B common stock is entitled to ten votes per share . Each share of Class B common stock is convertible into one share of Class A common stock at the option of the holder at any time or automatically upon certain events described in the Company’s amended and restated certificate of incorporation, including upon either the death or voluntary termination of the Company’s Executive Chairman. The Company allocates undistributed earnings attributable to common stock between the common stock classes on a one‑to‑one basis when computing net income per share. As a result, basic and diluted net income per share of Class A common stock and per share of Class B common stock are equivalent. During the three months ended June 30, 2023 and 2022 and the six months ended June 30, 2023 and 2022, no shares of Class B common stock were converted into Class A common stock. Basic net income (loss) per share (“Basic EPS”) is computed by dividing consolidated net income adjusted for net loss attributable to redeemable noncontrolling interest and changes in the redemption value of redeemable noncontrolling interest, if applicable, by the weighted-average number of common shares outstanding during the reporting period. The Company computes the weighted-average number of common shares outstanding during the reporting period using the total number of shares of Class A common stock and Class B common stock outstanding as of the last day of the previous year plus the weighted-average of any additional shares issued and outstanding during the reporting period, less the weighted-average of any shares repurchased during the period. Diluted net income (loss) per share (“Diluted EPS”) gives effect to all potentially dilutive securities. Diluted EPS is computed by dividing consolidated net income adjusted for net loss attributable to redeemable noncontrolling interest and changes in the redemption value of redeemable noncontrolling interest, if applicable and dilutive, by the weighted-average number of common shares outstanding during the reporting period using (i) the number of shares of common stock used in the Basic EPS calculation as indicated above, (ii) if dilutive, the incremental weighted-average common stock that the Company would issue upon the exercise of stock options and the vesting of RSUs, and (iii) if dilutive, market-based performance awards based on the number of shares that would be issuable as of the end of the reporting period assuming the end of the reporting period was also the end of the contingency period. The dilutive effect of these common stock equivalents is reflected in diluted earnings per share by application of the treasury stock method. The if-converted method is used to calculate the number of shares issuable upon exercise of the 2024 Put Right (as defined in Note 2 to the consolidated financial statements contained within the Annual Report), inclusive of CarOffer noncontrolling interest and incentive and subject units, that would be issuable as of the end of the reporting period assuming the end of the reporting period was also the end of the contingency period. For the three months ended June 30, 2023 and 2022 and for the six months ended June 30, 2023 and 2022, a reconciliation of the numerator and denominator used in the calculation of basic and diluted net income per share is as follows: Three Months Ended Six Months Ended 2023 2022 2023 2022 Numerator: Consolidated net income $ 13,817 $ 18,061 $ 25,683 $ 36,899 Net loss attributable to redeemable noncontrolling interest ( 2,596 ) ( 1,223 ) ( 6,862 ) ( 2,295 ) Accretion of redeemable noncontrolling interest to redemption value — 29,620 — 111,620 Net income (loss) attributable to common stockholders — basic $ 16,413 $ ( 10,336 ) $ 32,545 $ ( 72,426 ) Net loss attributable to redeemable noncontrolling interest ( 2,596 ) — ( 6,862 ) — Net income (loss) attributable to common stockholders — diluted $ 13,817 $ ( 10,336 ) $ 25,683 $ ( 72,426 ) Denominator: Weighted-average number of shares of common stock used 113,438,057 118,390,641 114,392,961 118,211,975 Dilutive effect of share equivalents resulting from stock 226,406 — 228,043 — Dilutive effect of share equivalents resulting from 826,188 — 576,886 — Weighted-average number of shares of common stock 114,490,651 118,390,641 115,197,890 118,211,975 Net income (loss) per share attributable to common stockholders: Basic $ 0.14 $ ( 0.09 ) $ 0.28 $ ( 0.61 ) Diluted $ 0.12 $ ( 0.09 ) $ 0.22 $ ( 0.61 ) For the three months ended June 30, 2023 and 2022 and for the six months ended June 30, 2023 and 2022, potentially dilutive common stock equivalents that have been excluded from the calculation of diluted weighted-average shares outstanding as their effect would have been anti-dilutive are as follows: Three Months Ended Six Months Ended 2023 2022 2023 2022 Stock options outstanding 558,080 885,547 559,054 914,870 Restricted stock units outstanding 2,291,538 4,296,625 2,749,365 4,186,653 CO Incentive Units, Subject Units and noncontrolling interest — 15,205,940 — 11,498,025 For the three and six months ended June 30, 2023, the number of issuable shares estimated upon exercise of the 2024 Put Right was zero. For the three and six months ended June 30, 2022, there was no effect of potentially dilutive shares as the numerator was negative. Additionally, during the three months ended March 31, 2022 , the Company modified its market-based performance awards to contain only service-based vesting conditions in line with the Company's other RSU awards. As a result, there are no market-based RSUs outstanding as of June 30, 2023 or 2022 .

Income Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2023
Income Tax Disclosure [Abstract]
Income Taxes	11. Income Taxes During the three months ended June 30, 2023 and 2022 and the six months ended June 30, 2023 and 2022, the Company recorded an income tax provision of $ 8,601 , $ 5,325 , $ 15,132 , and $ 13,027 , representing an effective tax rate of 34.4 % , 21.6 % , 31.7 % , and 25.0 % , respectively. The effective tax rates for the three months ended June 30, 2023 and 2022 and the six months ended June 30, 2023 and 2022 , were greater than the statutory tax rate of 21 %, principally due to state and local income taxes, shortfalls on the taxable compensation of stock-based awards, and the Section 162(m) excess officer compensation limitation, partially offset by federal and state research and development tax credits. The Company and its subsidiaries are subject to various U.S. federal, state, and foreign income tax examinations. The Company is currently not subject to income tax examination for the tax years of 2018 and prior as a result of applicable statute of limitations of the Internal Revenue Service and a majority of applicable state jurisdictions. The Company is currently not subject to examination in its foreign jurisdictions for tax years 2017 and prior.

Segment and Geographic Informat

Segment and Geographic Information	6 Months Ended
	Jun. 30, 2023
Segment Reporting [Abstract]
Segment and Geographic Information	12. Segment and Geographic Information Effective as of the fourth quarter of 2022, the Company revised its segment reporting from one reportable segment to two reportable segments, U.S. Marketplace and Digital Wholesale. The change in segment reporting was a triggering event for an evaluation of goodwill impairment. As such, the Company evaluated for goodwill impairment on December 31, 2022, and did not identify any impairment to its goodwill. The change in segment reporting was made to align with financial reporting results regularly provided to the Company's chief operating decision maker ("CODM") to assess the business. The CODM reviews segment revenue and segment income (loss) from operations as a proxy for the performance of the Company’s operations. The U.S. Marketplace segment derives revenue from marketplace services from customers within the United States. The Digital Wholesale segment derives revenue from Dealer-to-Dealer and IMCO services and products which are sold on the CarOffer platform. The Company also has two operating segments which are individually immaterial and therefore aggregated into the Other category to reconcile reportable segments to the Unaudited Condensed Consolidated Income Statements. The Other category derives revenue from marketplace services from customers outside of the United States. Revenue and costs discretely incurred by reportable segments, including depreciation and amortization, are included in the calculation of reportable segment income (loss) from operations. For the year ended December 31, 2022, Digital Wholesale segment income (loss) from operations did not reflect certain Dealer-to-Dealer and IMCO related capitalized website development amortization incurred by the U.S. Marketplace segment. During the three months ended March 31, 2023, the Company updated Digital Wholesale segment income (loss) from operations to reflect certain Dealer-to-Dealer and IMCO related capitalized website development amortization incurred by the U.S. Marketplace segment and accordingly updated Digital Wholesale segment income (loss) from operations for the three and six months ended June 30, 2022 for comparative purposes. Digital Wholesale segment income (loss) from operations also reflects certain IMCO marketing and lead generation fees allocated from the U.S. Marketplace segment. Asset information by reportable segment is not provided to the CODM as asset information is assessed and reviewed on a consolidated basis. For the three months ended June 30, 2023 and 2022 and for the six months ended June 30, 2023 and 2022, segment revenue, segment income (loss) from operations, and segment depreciation and amortization are as follows: Three Months Ended Six Months Ended 2023 2022 2023 2022 Segment Revenue U.S. Marketplace $ 158,443 $ 152,753 $ 314,064 $ 304,642 Digital Wholesale 68,787 347,303 133,623 614,622 Other 12,507 11,173 24,013 22,573 Total $ 239,737 $ 511,229 $ 471,700 $ 941,837 Three Months Ended Six Months Ended 2023 2022 2023 2022 Segment Income (Loss) from Operations: U.S. Marketplace $ 24,619 $ 28,346 $ 51,158 $ 58,182 Digital Wholesale ( 6,307 ) ( 2,638 ) ( 17,532 ) ( 4,749 ) Other ( 574 ) ( 2,166 ) ( 1,829 ) ( 3,232 ) Total $ 17,738 $ 23,542 $ 31,797 $ 50,201 Three Months Ended Six Months Ended 2023 2022 2023 2022 Segment Depreciation and Amortization: U.S. Marketplace $ 2,823 $ 2,879 $ 5,563 $ 5,819 Digital Wholesale 8,701 8,257 17,394 16,379 Other 143 98 286 221 Total $ 11,667 $ 11,234 $ 23,243 $ 22,419 For the three months ended June 30, 2023 and 2022 and for the six months ended June 30, 2023 and 2022, a reconciliation between total segment income from operations to consolidated income before income taxes is as follows: Three Months Ended Six Months Ended 2023 2022 2023 2022 Total segment income from operations $ 17,738 $ 23,542 $ 31,797 $ 50,201 Other income (expense), net 4,680 ( 156 ) 9,018 ( 275 ) Consolidated income before income taxes $ 22,418 $ 23,386 $ 40,815 $ 49,926 As of June 30, 2023 and December 31, 2022, segment assets are as follows: As of As of (1) Segment Assets: U.S. Marketplace $ 656,728 $ 525,103 Digital Wholesale 334,712 358,289 Other 48,881 43,710 Total $ 1,040,321 $ 927,102 (1) As of December 31, 2022, Digital Wholesale assets did not reflect certain Dealer-to-Dealer and IMCO related capitalized website development assets from the U.S. Marketplace segment. During the three months ended March 31, 2023, the Company updated Digital Wholesale assets to reflect certain Dealer-to-Dealer and IMCO related capitalized website development amortization assets from the U.S. Marketplace segment and accordingly updated Digital Wholesale assets as of December 31, 2022 for comparative purposes. For the three months ended June 30, 2023 and 2022 and for the six months ended June 30, 2023 and 2022, revenue by geographic region is as follows: Three Months Ended Six Months Ended 2023 2022 2023 2022 Revenue by Geographic Region: United States $ 227,230 $ 500,056 $ 447,687 $ 919,264 International 12,507 11,173 24,013 22,573 Total $ 239,737 $ 511,229 $ 471,700 $ 941,837

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2023
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying interim condensed consolidated financial statements are unaudited (the “Unaudited Condensed Consolidated Financial Statements”). The Unaudited Condensed Consolidated Financial Statements and related disclosures have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”). Any reference in these notes to applicable guidance is meant to refer to GAAP as found in the Accounting Standards Codification (“ASC”) and Accounting Standards Update of the Financial Accounting Standards Board (“FASB”). The Unaudited Condensed Consolidated Financial Statements have also been prepared pursuant to the rules and regulations of the U.S. Securities and Exchange Commission (“SEC”). Accordingly, certain information and footnote disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations. The Unaudited Condensed Consolidated Financial Statements reflect all adjustments, consisting of only normal recurring adjustments, necessary for the fair presentation of the Company’s financial position as of June 30, 2023 and December 31, 2022, results of operations, comprehensive income, and changes in stockholders’ equity for the three months ended June 30, 2023 and 2022 and for the six months ended June 30, 2023 and 2022, and cash flows for the six months ended June 30, 2023 and 2022. These interim period results are not necessarily indicative of the results to be expected for any other interim period or the full year. The Unaudited Condensed Consolidated Financial Statements should be read in conjunction with the Company’s audited consolidated financial statements and the notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2022, filed with the SEC on March 1, 2023 (the “Annual Report”). While the Company disclosed interest income within other income (expense), net in the Unaudited Condensed Consolidated Income Statements in the Company's Quarterly Report on Form 10-Q for the quarter ended June 30, 2022, filed with the SEC on August 8, 2022, the accompanying Unaudited Condensed Consolidated Income Statements for the quarter ended June 30, 2022 present interest income separately from other income (expense), net to conform to the current year presentation, as interest income met the threshold for separate disclosure.
Principles of Consolidation	Principles of Consolidation The Unaudited Condensed Consolidated Financial Statements include the accounts of the Company and its subsidiaries. All intercompany balances and transactions have been eliminated in consolidation.
Subsequent Event Considerations	Subsequent Event Considerations The Company considers events or transactions that occur after the balance sheet date but prior to the issuance of the financial statements to provide additional evidence for certain estimates or to identify matters that require additional disclosure. The Company has evaluated all subsequent events and determined that there are no material recognized or unrecognized subsequent events requiring disclosure.
Use of Estimates	Use of Estimates The preparation of the Unaudited Condensed Consolidated Financial Statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, and the disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenue and expenses during the reporting period. Although the Company regularly assesses these estimates, actual results could differ materially from these estimates. The Company bases its estimates on historical experience and various other assumptions that it believes to be reasonable under the circumstances. Actual results may differ from management’s estimates if these results differ from historical experience, or other assumptions do not turn out to be substantially accurate, even if such assumptions are reasonable when made. Changes in estimates are recognized in the period in which they become known. Critical estimates relied upon in preparing the Unaudited Condensed Consolidated Financial Statements include the determination of sales allowance and variable consideration in the Company’s revenue recognition, allowance for doubtful accounts, the impairment of long-lived assets, the capitalization of product, technology, and development costs for website development, internal-use software and hosting arrangements, the valuation of acquired assets and liabilities, the valuation and recoverability of intangible assets and goodwill, the valuation of redeemable noncontrolling interest, the recoverability of the Company’s net deferred tax assets and related valuation allowance, the valuation of inventory, and the valuation of equity and liability-classified compensation awards. Accordingly, the Company considers these to be its critical accounting estimates, and believes that of the Company’s significant accounting policies, these involve the greatest degree of judgment and complexity.
Concentration of Credit Risk	Concentration of Credit Risk The Company has no significant off-balance sheet risk, such as foreign exchange contracts, option contracts, or other foreign hedging arrangements. Financial instruments that potentially expose the Company to concentrations of credit risk consist primarily of cash, cash equivalents, short-term investments, trade accounts receivable, and other receivables. The Company maintains its cash, cash equivalents, and short-term investments principally with accredited financial institutions of high credit standing. Although the Company deposits its cash, cash equivalents, and short-term investments with multiple financial institutions, its deposits with each such financial institution exceed governmental insured limits. The Company routinely assesses the creditworthiness of its customers and does not require collateral. The Company generally has not experienced any material losses related to receivables from individual customers or groups of customers. The majority of the Company's accounts receivable results from wholesale and product revenue transactions. The Company has had no material losses related to wholesale and product receivables as the third-party transaction processor does not release the title to the vehicle until successfully collecting funds from the buying dealer. Titling is handled by the Company's third-party transaction processor and titles are held in escrow until it collects funds from the buying dealer (i.e., title is legally transferred from the selling party to the buying party upon signing of bill of sale, but title is held in escrow by the third-party transaction processor until payment is received). Due to these factors, no additional credit risk beyond amounts provided for collection losses is believed by management to be probable in the Company’s accounts receivable and other receivables. As of June 30, 2023 , one customer accounted for 11 % of net accounts receivable and other receivables. As of December 31, 2022 , one customer accounted for 13 % of net accounts receivable. The remainder of the accounts receivable was dispersed among more than 1,000 custo mers. The customers who accounted for greater than 10 % of net accounts receivable are related to wholesale and product receivables. The collection risk associated with these customers is mitigated because, as discussed above, the third-party transaction processor does not release the title on vehicles until funds are successfully collected. Furthermore, there is no significant credit risk with respect to accounts receivable because, other than the receivables associated with these customers, credit risk with respect to accounts receivable is dispersed due to the large number of customers. For the three and six months ended June 30, 2023 , no individual customer accounted for more than 10% of total revenue. For the three months ended June 30, 2022 , two customers each accounted for 11 % of total revenue due to the continued growth of the CarOffer business. For the six months ended June 30, 2022 , no individual customer accounted for more than 10% of total revenue. The Company is exposed to credit losses primarily through its trade accounts receivable, which includes receivables in transit, net of payables due, from a third-party transaction processor. The third-party transaction processor collects customer payments on the Company's behalf and remits them to the Company. Customer payments received by the third-party transaction processor, but not remitted to the Company as of period end are deemed to be receivables in transit, net of payables due. Additionally, the third-party transaction processor provides payments in advance for certain selling dealers. If the third-party transaction processor does not receive buying dealer payments associated with the transaction paid in advance, the Company would guarantee losses incurred by the third-party transaction processor and the balance would be deducted from future remittances to the Company. To date, losses associated with these guarantees have not been material. The Company offsets trade accounts receivables in transit, net of payables due, from the third-party transaction processor with payments received in advance from the third-party transaction processor as it has the right of offset. At any point in time, the Company could have amounts due from the third-party transaction processor for funds the third-party transaction processor has collected from buying dealers and has not yet remitted to the Company (i.e., receivables in transit, net of payables due), as well as amounts paid by the third-party transaction processor to the Company in advance of collecting payments from buying dealers (i.e., payments received in advance). Therefore, as the Company has the right to offset, the Company can either have a net receivable balance due from the third-party transaction processor which is recognized within accounts receivable, net in the Unaudited Condensed Consolidated Balance Sheets, or the Company can have a net liability which is recognized within accrued expenses, accrued income taxes, and other current liabilities in the Unaudited Condensed Consolidated Balance Sheets if the advance payments exceed the receivable position from the third-party transaction processor as of the balance sheet date. Payments received in advance from the third-party transaction processor are presented as cash flows from financing activities in the Unaudited Condensed Consolidated Statements of Cash Flows. As of June 30, 2023, trade accounts receivable from receivables in transit, net of payables due, from the third-party transaction processor was $ 2,427 , offset by payments received in advance of $ 3,816 , which resulted in a net payable of $ 1,389 recognized within accrued expenses, accrued income taxes, and other current liabilities in the Unaudited Condensed Consolidated Balance Sheets. As of December 31, 2022, trade accounts receivable from receivables in transit, net of payables due, from the third-party transaction processor was $ 7,122 , offset by payments received in advance of $ 6,490 , which resulted in a net receivable of $ 632 recognized within accounts receivable, net in the Unaudited Condensed Consolidated Balance Sheets. As of June 30, 2023 and December 31, 2022, $ 7,655 and $ 7,150 , respectively , was included in net accounts receivable, representing unbilled accounts receivable relating primarily to advertising customers invoiced in the period subsequent to services rendered.
Significant Accounting Policies	Significant Accounting Policies The Unaudited Condensed Consolidated Financial Statements reflect the application of certain significant accounting policies as described below and elsewhere in these notes to the Unaudited Condensed Consolidated Financial Statements. As of June 30, 2023 , there have been no material changes in the Company’s significant accounting policies, which are detailed in the Annual Report, other than those described below.
Cash, Cash Equivalents, and Investments	Cash, Cash Equivalents, and Investments As of June 30, 2023 and December 31, 2022, cash and cash equivalents primarily consist of cash on deposit with banks, amounts held in interest-bearing money market accounts, and investments with original maturities of 90 days or less. Cash equivalents are carried at cost, which approximates their fair market value. The Company’s investment policy, which was approved by the Audit Committee of the Company’s Board of Directors (the “Board”), permits investments in fixed income securities, including U.S. government and agency securities, non‑U.S. government securities, money market instruments, commercial paper, certificates of deposit, corporate bonds, and asset‑backed securities. The Company considers all highly liquid investments with an original maturity of 90 days or less at the date of purchase to be cash equivalents. Investments not classified as cash equivalents with maturities less than one year from the balance sheet date are classified as short‑term investments, while investments with maturities in excess of one year from the balance sheet date are classified as long‑term investments. Management determines the appropriate classification of investments at the time of purchase, and re‑evaluates such determination at each balance sheet date. Investments in equity securities with readily determinable fair values are recognized at fair value based on quoted market prices within investments in the Unaudited Condensed Consolidated Balance Sheets. Investments in held-to-maturity debt securities are recognized at amortized cost within investments in the Unaudited Condensed Consolidated Balance Sheets. The Company adjusts the cost of investments in held-to-maturity debt securities for amortization of premiums and accretion of discounts to maturity, if any. Investments in trading and available-for-sale debt securities are recognized at fair value within investments in the Unaudited Condensed Consolidated Balance Sheets. Purchases of equity securities and debt securities are recognized within investing activities in the Unaudited Condensed Consolidated Statements of Cash Flows. Dividend income from equity securities is recognized within interest income in the Unaudited Condensed Consolidated Income Statements. Reinvested proceeds from dividend income are recognized within purchases of investments in investing activities in the Unaudited Condensed Consolidated Statements of Cash Flows. The revaluation of equity securities and debt securities results in an unrealized gain or loss. Unrealized gains or losses on equity securities and trading debt securities are recognized within other income (expense), net in the Unaudited Condensed Consolidated Income Statements and backed out of operating activities in the Unaudited Condensed Consolidated Statements of Cash Flows. Unrealized gains or losses on available-for-sale debt securities are recognized within other comprehensive income in the Unaudited Condensed Consolidated Statements of Comprehensive Income. Interest on held-to-maturity debt securities is recognized within interest income in the Unaudited Condensed Consolidated Income Statements. Proceeds from sale of equity securities and debt securities are recognized within investing activities in the Unaudited Condensed Consolidated Statements of Cash Flows. Realized gains and losses on sale of equity securities and debt securities are recognized within other (expense) income, net in the Unaudited Condensed Consolidated Income Statements, backed out of operating activities in the Unaudited Condensed Consolidated Cash Flows, and recognized within proceeds from sale of equity securities and debt securities in investing activities in the Unaudited Condensed Consolidated Statements of Cash Flows. Debt securities are reviewed for other‑than‑temporary impairment whenever the fair value of an investment is less than the amortized cost and evidence indicates that an investment’s carrying amount is not recoverable within a reasonable period of time. Other‑than‑temporary impairments of debt securities are recognized within other income (expense), net in the Unaudited Condensed Consolidated Income Statements if the Company has experienced a credit loss or if it is more likely than not that the Company will be required to sell the investment before recovery of the amortized cost basis. Evidence considered in this assessment includes reasons for the impairment, compliance with the Company’s investment policy, the severity and duration of the impairment, and changes in value subsequent to the end of the period. As of June 30, 2023, the Company held short-term investments in equity securities. As of December 31, 2022, the Company held no investments.
Recent Accounting Pronouncements not Yet Adopted	Recent Accounting Pronouncements Not Yet Adopted From time to time, new accounting pronouncements are issued by the FASB or other standard setting bodies and adopted by the Company on or prior to the specified effective date. Unless otherwise discussed, the Company believes that the impact of recently issued standards that are not yet effective will not have a material impact on its financial position or results of operations upon adoption. As of June 30, 2023 , there are no new material accounting pronouncements that the Company is considering adopting.
Earnings Per Share	The Company has two classes of common stock authorized: Class A common stock and Class B common stock. The rights of the holders of Class A and Class B common stock are identical, except with respect to voting and conversion. Each share of Class A common stock is entitled to one vote per share and each share of Class B common stock is entitled to ten votes per share . Each share of Class B common stock is convertible into one share of Class A common stock at the option of the holder at any time or automatically upon certain events described in the Company’s amended and restated certificate of incorporation, including upon either the death or voluntary termination of the Company’s Executive Chairman. The Company allocates undistributed earnings attributable to common stock between the common stock classes on a one‑to‑one basis when computing net income per share. As a result, basic and diluted net income per share of Class A common stock and per share of Class B common stock are equivalent.

Revenue Recognition (Tables)

Revenue Recognition (Tables)	6 Months Ended
	Jun. 30, 2023
Revenue from Contract with Customer [Abstract]
Summary of Revenue from Contracts with Customers by Product	The following table summarizes revenue from contracts with customers by services and products for the three months ended June 30, 2023 and 2022 and for the six months ended June 30, 2023 and 2022: Three Months Ended Six Months Ended 2023 2022 2023 2022 Marketplace $ 170,950 $ 163,926 $ 338,077 $ 327,215 Dealer-to-Dealer 32,950 97,064 61,655 202,555 Instant Max Cash Offer 35,837 250,239 71,968 412,067 Total $ 239,737 $ 511,229 $ 471,700 $ 941,837

Fair Value of Financial Instr_2

Fair Value of Financial Instruments (Tables)	6 Months Ended
	Jun. 30, 2023
Fair Value Disclosures [Abstract]
Schedule of Fair Value Levels, Assets Measured at Fair Value on Recurring Basis	As of June 30, 2023 and December 31, 2022, assets measured at fair value on a recurring basis consist of the following: As of June 30, 2023 Quoted Prices Significant Other Significant Total Cash equivalents: Mutual funds $ 204,560 $ — $ — $ 204,560 Short-term investments: Mutual funds 90,490 — — 90,490 Total $ 295,050 $ — $ — $ 295,050 As of December 31, 2022 Quoted Prices Significant Other Significant Total Cash equivalents: Mutual funds $ 175,486 $ — $ — $ 175,486 Total $ 175,486 $ — $ — $ 175,486

Property and Equipment, Net (Ta

Property and Equipment, Net (Tables)	6 Months Ended
	Jun. 30, 2023
Property, Plant and Equipment [Abstract]
Schedule of Property and Equipment, Net	As of June 30, 2023 and December 31, 2022, property and equipment, net consist of the following: As of As of Capitalized equipment $ 1,297 $ 7,877 Capitalized internal-use software 9,547 7,429 Capitalized website development 45,643 36,369 Furniture and fixtures 8,904 8,615 Leasehold improvements 24,322 24,225 Construction in progress 8,641 4,161 Finance lease right-of-use assets 354 420 98,708 89,096 Less accumulated depreciation and amortization ( 50,465 ) ( 48,968 ) Total $ 48,243 $ 40,128

Accrued Expenses, Accrued Inc_2

Accrued Expenses, Accrued Income Taxes and Other Current Liabilities (Tables)	6 Months Ended
	Jun. 30, 2023
Payables and Accruals [Abstract]
Schedule of Accrued Expenses, Accrued Income Taxes and Other Current Liabilities	As of June 30, 2023 and December 31, 2022, accrued expenses, accrued income taxes, and other current liabilities consist of the following: As of As of Accrued bonus $ 11,874 $ 11,007 Other accrued expenses, accrued income taxes, and other current liabilities 24,493 28,186 Total $ 36,367 $ 39,193

Commitments and Contingencies (

Commitments and Contingencies (Tables)	6 Months Ended
	Jun. 30, 2023
Commitments and Contingencies Disclosure [Abstract]
Summary of Future Minimum Lease Payments	As of June 30, 2023, future minimum lease payments for all leases are as follows: Year Ending December 31, Operating Remainder of 2023 $ 5,974 2024 15,922 2025 18,592 2026 22,334 2027 22,742 Thereafter 231,155 Total lease payments $ 316,719 Less imputed interest ( 109,665 ) Total $ 207,054 The table above does not include leases signed but not yet commenced as of June 30, 2023. As of June 30, 2023, total estimated future minimum lease payments for leases signed but not yet commenced are estimated to be $ 1,093 . The lease is expected to commence in the current fiscal year with lease terms of approximately two years .
Schedule of Future Minimum Sublease Income Payments	As of June 30, 2023, future minimum sublease income payments are as follows: Year Ending December 31, Sublease Remainder of 2023 $ 1,120 2024 1,951 2025 1,023 2026 — 2027 — Thereafter — Total $ 4,094

Stock-based Compensation and _2

Stock-based Compensation and Common Stock Share Repurchases (Tables)	6 Months Ended
	Jun. 30, 2023
Share-Based Payment Arrangement [Abstract]
Summary of Stock-based Compensation Expense by Award Type	For the three months ended June 30, 2023 and 2022 and for the six months ended June 30, 2023 and 2022, stock-based compensation expense by award type and where the stock-based compensation expense was recognized in the Unaudited Condensed Consolidated Income Statements is as follows: Three Months Ended Six Months Ended 2023 2022 2023 2022 Options $ 590 $ 646 $ 1,204 $ 1,290 Restricted Stock Units 14,012 12,786 28,375 26,289 CO Incentive Units and Subject Units 1,225 13,025 1,225 26,720 Total $ 15,827 $ 26,457 $ 30,804 $ 54,299
Summary of Allocation of Stock-based Compensation Expense	Three Months Ended Six Months Ended 2023 2022 2023 2022 Cost of revenue $ 185 $ 69 $ 328 $ 205 Sales and marketing expense 2,872 4,086 5,956 8,069 Product, technology, and development expense 6,034 6,151 12,323 12,519 General and administrative expense 6,736 16,151 12,197 33,506 Total $ 15,827 $ 26,457 $ 30,804 $ 54,299

Earnings Per Share (Tables)

Earnings Per Share (Tables)	6 Months Ended
	Jun. 30, 2023
Earnings Per Share [Abstract]
Schedule of Reconciliation of Numerator and Denominator Used in Calculation of Basic and Diluted Net Income Per Share	For the three months ended June 30, 2023 and 2022 and for the six months ended June 30, 2023 and 2022, a reconciliation of the numerator and denominator used in the calculation of basic and diluted net income per share is as follows: Three Months Ended Six Months Ended 2023 2022 2023 2022 Numerator: Consolidated net income $ 13,817 $ 18,061 $ 25,683 $ 36,899 Net loss attributable to redeemable noncontrolling interest ( 2,596 ) ( 1,223 ) ( 6,862 ) ( 2,295 ) Accretion of redeemable noncontrolling interest to redemption value — 29,620 — 111,620 Net income (loss) attributable to common stockholders — basic $ 16,413 $ ( 10,336 ) $ 32,545 $ ( 72,426 ) Net loss attributable to redeemable noncontrolling interest ( 2,596 ) — ( 6,862 ) — Net income (loss) attributable to common stockholders — diluted $ 13,817 $ ( 10,336 ) $ 25,683 $ ( 72,426 ) Denominator: Weighted-average number of shares of common stock used 113,438,057 118,390,641 114,392,961 118,211,975 Dilutive effect of share equivalents resulting from stock 226,406 — 228,043 — Dilutive effect of share equivalents resulting from 826,188 — 576,886 — Weighted-average number of shares of common stock 114,490,651 118,390,641 115,197,890 118,211,975 Net income (loss) per share attributable to common stockholders: Basic $ 0.14 $ ( 0.09 ) $ 0.28 $ ( 0.61 ) Diluted $ 0.12 $ ( 0.09 ) $ 0.22 $ ( 0.61 )
Schedule of Potentially Dilutive Common Stock Equivalents Excluded from Calculation of Diluted Weighted-average Shares Outstanding	For the three months ended June 30, 2023 and 2022 and for the six months ended June 30, 2023 and 2022, potentially dilutive common stock equivalents that have been excluded from the calculation of diluted weighted-average shares outstanding as their effect would have been anti-dilutive are as follows: Three Months Ended Six Months Ended 2023 2022 2023 2022 Stock options outstanding 558,080 885,547 559,054 914,870 Restricted stock units outstanding 2,291,538 4,296,625 2,749,365 4,186,653 CO Incentive Units, Subject Units and noncontrolling interest — 15,205,940 — 11,498,025

Segment and Geographic Inform_2

Segment and Geographic Information (Tables)	6 Months Ended
	Jun. 30, 2023
Segment Reporting [Abstract]
Summary of Segment Revenue, Income (Loss) and Depreciation and Amortization	For the three months ended June 30, 2023 and 2022 and for the six months ended June 30, 2023 and 2022, segment revenue, segment income (loss) from operations, and segment depreciation and amortization are as follows: Three Months Ended Six Months Ended 2023 2022 2023 2022 Segment Revenue U.S. Marketplace $ 158,443 $ 152,753 $ 314,064 $ 304,642 Digital Wholesale 68,787 347,303 133,623 614,622 Other 12,507 11,173 24,013 22,573 Total $ 239,737 $ 511,229 $ 471,700 $ 941,837 Three Months Ended Six Months Ended 2023 2022 2023 2022 Segment Income (Loss) from Operations: U.S. Marketplace $ 24,619 $ 28,346 $ 51,158 $ 58,182 Digital Wholesale ( 6,307 ) ( 2,638 ) ( 17,532 ) ( 4,749 ) Other ( 574 ) ( 2,166 ) ( 1,829 ) ( 3,232 ) Total $ 17,738 $ 23,542 $ 31,797 $ 50,201 Three Months Ended Six Months Ended 2023 2022 2023 2022 Segment Depreciation and Amortization: U.S. Marketplace $ 2,823 $ 2,879 $ 5,563 $ 5,819 Digital Wholesale 8,701 8,257 17,394 16,379 Other 143 98 286 221 Total $ 11,667 $ 11,234 $ 23,243 $ 22,419
Summary of Reconciliation Between Segment Income from Operations	For the three months ended June 30, 2023 and 2022 and for the six months ended June 30, 2023 and 2022, a reconciliation between total segment income from operations to consolidated income before income taxes is as follows: Three Months Ended Six Months Ended 2023 2022 2023 2022 Total segment income from operations $ 17,738 $ 23,542 $ 31,797 $ 50,201 Other income (expense), net 4,680 ( 156 ) 9,018 ( 275 ) Consolidated income before income taxes $ 22,418 $ 23,386 $ 40,815 $ 49,926
Summary of Assets by Segment	As of June 30, 2023 and December 31, 2022, segment assets are as follows: As of As of (1) Segment Assets: U.S. Marketplace $ 656,728 $ 525,103 Digital Wholesale 334,712 358,289 Other 48,881 43,710 Total $ 1,040,321 $ 927,102 (1) As of December 31, 2022, Digital Wholesale assets did not reflect certain Dealer-to-Dealer and IMCO related capitalized website development assets from the U.S. Marketplace segment. During the three months ended March 31, 2023, the Company updated Digital Wholesale assets to reflect certain Dealer-to-Dealer and IMCO related capitalized website development amortization assets from the U.S. Marketplace segment and accordingly updated Digital Wholesale assets as of December 31, 2022 for comparative purposes.
Summary of Revenue by Geographic Region	For the three months ended June 30, 2023 and 2022 and for the six months ended June 30, 2023 and 2022, revenue by geographic region is as follows: Three Months Ended Six Months Ended 2023 2022 2023 2022 Revenue by Geographic Region: United States $ 227,230 $ 500,056 $ 447,687 $ 919,264 International 12,507 11,173 24,013 22,573 Total $ 239,737 $ 511,229 $ 471,700 $ 941,837

Organization and Business Des_2

Organization and Business Description - Additional Information (Details) - Segment	3 Months Ended	6 Months Ended	9 Months Ended
	Dec. 31, 2022	Jun. 30, 2023	Sep. 30, 2022	Jan. 14, 2021
Business Acquisition [Line Items]
State of incorporation		DE
Date of incorporation		Jun. 26, 2015
Number of reportable segments	2	2	1
Car Offer
Business Acquisition [Line Items]
Business acquisition, percentage of interest acquired		51%		51%

Summary of Significant Accoun_3

Summary of Significant Accounting Policies - Additional Information (Details) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2023 USD ($) Customer	Jun. 30, 2022 Customer	Jun. 30, 2023 USD ($) Customer	Jun. 30, 2022 Customer	Dec. 31, 2022 USD ($) Customer
Summary Of Significant Accounting Policies [Line Items]
Description of significant off-balance sheet risk			The Company has no significant off-balance sheet risk, such as foreign exchange contracts, option contracts, or other foreign hedging arrangements.
Accounts receivable, net	$ 37,820		$ 37,820		$ 46,817
Accounts payable, net	39,260		39,260		32,529
Investments					0
Accrued Expenses, Accrued Income Taxes and Other Current Liabilities
Summary Of Significant Accounting Policies [Line Items]
Trade accounts payable, net of payables	1,389		1,389
Receivables offset by payments received in advance	3,816		3,816
Accounts payable, net	$ 2,427		$ 2,427
Trade Accounts Receivable [Member]
Summary Of Significant Accounting Policies [Line Items]
Trade accounts receivable from receivables in transit, net of payables due, from the third-party payment processor					632
Receivables offset by payments received in advance					6,490
Accounts receivable, net					7,122
Sales Revenue, Net | Customer Concentration Risk
Summary Of Significant Accounting Policies [Line Items]
Number of major customers | Customer	0	2	0	0
Sales Revenue, Net | Customer Concentration Risk | Customer One
Summary Of Significant Accounting Policies [Line Items]
Concentration of credit risk, percentage		11%
Sales Revenue, Net | Customer Concentration Risk | Customer Two
Summary Of Significant Accounting Policies [Line Items]
Concentration of credit risk, percentage		11%
Accounts Receivable and Other Receivables | Customer Concentration Risk
Summary Of Significant Accounting Policies [Line Items]
Number of major customers | Customer			1
Accounts Receivable and Other Receivables | Customer Concentration Risk | Customer One
Summary Of Significant Accounting Policies [Line Items]
Concentration of credit risk, percentage			11%
Net Accounts Receivable | Advertising Customers
Summary Of Significant Accounting Policies [Line Items]
Unbilled accounts receivable	$ 7,655		$ 7,655		$ 7,150
Net Accounts Receivable | Customer Concentration Risk
Summary Of Significant Accounting Policies [Line Items]
Number of major customers | Customer					1
Net Accounts Receivable | Customer Concentration Risk | Customer One
Summary Of Significant Accounting Policies [Line Items]
Concentration of credit risk, percentage					13%
Minimum | Net Accounts Receivable | Customer Concentration Risk
Summary Of Significant Accounting Policies [Line Items]
Number of major customers | Customer			1,000
Minimum | Net Accounts Receivable | Customer Concentration Risk | Customer One
Summary Of Significant Accounting Policies [Line Items]
Concentration of credit risk, percentage			10%

Revenue Recognition - Summary o

Revenue Recognition - Summary of Revenue from Contracts with Customers by Product (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Disaggregation of Revenue [Line Items]
Revenue	$ 239,737	$ 511,229	$ 471,700	$ 941,837
Marketplace
Disaggregation of Revenue [Line Items]
Revenue	170,950	163,926	338,077	327,215
Dealer-to-Dealer
Disaggregation of Revenue [Line Items]
Revenue	32,950	97,064	61,655	202,555
Instant Max Cash Offer
Disaggregation of Revenue [Line Items]
Revenue	$ 35,837	$ 250,239	$ 71,968	$ 412,067

Revenue Recognition - Additiona

Revenue Recognition - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Revenue from Contract with Customer [Abstract]
Revenue recognized	$ 20,808	$ 12,776	$ 12,249	$ 12,784
Performance obligation unsatisfied	$ 18,500		$ 18,500

Fair Value of Financial Instr_3

Fair Value of Financial Instruments - Schedule of Fair Value Levels, Assets Measured at Fair Value on Recurring Basis (Details) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	$ 295,050	$ 175,486
Quoted Prices in Active Markets for Identical Assets (Level 1 Inputs)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	295,050	175,486
Mutual funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents:	204,560	175,486
Mutual funds | Quoted Prices in Active Markets for Identical Assets (Level 1 Inputs)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents:	204,560	$ 175,486
Mutual Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	90,490
Mutual Funds | Quoted Prices in Active Markets for Identical Assets (Level 1 Inputs)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	$ 90,490

Fair Value of Financial Instr_4

Fair Value of Financial Instruments - Additional Information (Details)	Dec. 31, 2022 USD ($)
Fair Value Disclosures [Abstract]
Investments	$ 0

Property and Equipment, Net - S

Property and Equipment, Net - Schedule of Property and Equipment, Net (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 98,708	$ 89,096
Less accumulated depreciation and amortization	(50,465)	(48,968)
Property and equipment, net	48,243	40,128
Capitalized Equipment
Property Plant And Equipment [Line Items]
Property and equipment, gross	1,297	7,877
Capitalized internal-use software
Property Plant And Equipment [Line Items]
Property and equipment, gross	9,547	7,429
Capitalized Website Development
Property Plant And Equipment [Line Items]
Property and equipment, gross	45,643	36,369
Furniture and Fixtures
Property Plant And Equipment [Line Items]
Property and equipment, gross	8,904	8,615
Leasehold Improvements
Property Plant And Equipment [Line Items]
Property and equipment, gross	24,322	24,225
Construction in Progress
Property Plant And Equipment [Line Items]
Property and equipment, gross	8,641	4,161
Finance Lease Right-of-use Assets
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 354	$ 420

Property and Equipment, Net - A

Property and Equipment, Net - Additional Information (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Property, Plant and Equipment [Line Items]
Depreciation and amortization excluding amortization of intangible assets and capitalized hosting arrangements	$ 4,160,000	$ 3,562,000	$ 8,202,000	$ 7,042,000
Digital Wholesale
Property, Plant and Equipment [Line Items]
Write-offs in capitalized website development costs		$ 0		$ 0
U.S. Marketplace
Property, Plant and Equipment [Line Items]
Write-offs in capitalized website development costs	$ 9,000
Digital Wholesale and U.S. Marketplace
Property, Plant and Equipment [Line Items]
Write-offs in capitalized website development costs			184,000
Capitalized Website Development
Property, Plant and Equipment [Line Items]
Increase (decrease) in property and equipment			9,274,000
Construction in Progress
Property, Plant and Equipment [Line Items]
Increase (decrease) in property and equipment			4,480,000
Capitalized Equipment
Property, Plant and Equipment [Line Items]
Increase (decrease) in property and equipment			$ (6,580,000)

Accrued Expenses, Accrued Inc_3

Accrued Expenses, Accrued Income Taxes and Other Current Liabilities - Schedule of Accrued Expenses, Accrued Income Taxes and Other Current Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Accrued Liabilities, Current [Abstract]
Accrued bonus	$ 11,874	$ 11,007
Other accrued expenses, accrued income taxes, and other current liabilities	24,493	28,186
Total	$ 36,367	$ 39,193

Debt - Additional Information (

Debt - Additional Information (Details) - USD ($)		3 Months Ended		6 Months Ended
	Sep. 26, 2022	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
Debt Instrument [Line Items]
Long-term debt outstanding		$ 0		$ 0		$ 0
Line of credit facility maturity date				Sep. 26, 2027
Amortization of deferred financing costs				$ 258,000
Revolving Credit Facility
Debt Instrument [Line Items]
Line of credit facility maximum borrowing amount	$ 400,000,000	399,258,000		399,258,000
Letter of credit facility		0		0		0
Line of credit facility increased in maximum borrowing capacity	$ 250,000,000
Increase in borrowing capacity equal to percentage of four quarter EBDITA	100%
Deferred financing costs		2,184,000		2,184,000		2,442,000
Amortization of deferred financing costs		129,000	$ 0	258,000	$ 0
Minimum | Revolving Credit Facility
Debt Instrument [Line Items]
Line of credit facility unutilized commitment fee percentage	0.125%
Maximum | Revolving Credit Facility
Debt Instrument [Line Items]
Line of credit facility unutilized commitment fee percentage	0.175%
Letter of Credit Facility | Revolving Credit Facility
Debt Instrument [Line Items]
Letter of credit facility	$ 50,000,000	$ 742,000		$ 742,000		$ 0

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2023 USD ($)	Jun. 30, 2022 USD ($)	Jun. 30, 2023 USD ($) Days	Jun. 30, 2022 USD ($)	Feb. 03, 2023 ft²	Dec. 31, 2022 USD ($)	Jan. 14, 2021
Commitments And Contingencies [Line Items]
Restricted cash	$ 11,561,000		$ 11,561,000			$ 14,615,000
Lease costs	$ 9,103,000	$ 4,176,000	$ 16,547,000	$ 8,228,000
Weighted average remaining lease term	13 years 2 months 12 days		13 years 2 months 12 days
Weighted average discount rate	5.70%		5.70%
Reclassified line of credit from long-term asset to short-term asset			$ 9,378,000
Guarantee income	$ 546,000	2,292,000	1,160,000	5,595,000
Exercise of guarantee net loss	164,000	$ 259,000	89,000	$ 2,083,000
Maximum potential amount of future payments required to make under guarantees	19,367,000		19,367,000			31,056,000
Estimated future minimum lease payments not yet commenced	1,093,000		$ 1,093,000
Lessee operating lease expected to commence lease terms			2 years
2022 Revolver Sub-facility
Commitments And Contingencies [Line Items]
Letter of credit facility	0		$ 0			$ 0
1001 Boylston Street
Commitments And Contingencies [Line Items]
Contract commitments	2,526,000		2,526,000
Expected contractual obligations and commitments in connection with lease net of tenant reimbursements	69,815,000		69,815,000
Contractual obligations incurred expenses	8,835,000		$ 8,835,000
Area of land | ft²					225,428
Lessee, Operating Lease, Existence of Option to Extend [true false]			true
Operating lease, option to extend			options to extend the lease term for two additional periods of five years.
Contractual obligations capitalized amount	8,641,000		$ 8,641,000
San Francisco and Cambridge | 2022 Revolver Sub-facility
Commitments And Contingencies [Line Items]
Letter of credit facility	742,000		742,000
1001 Boylston Street and Cambridge
Commitments And Contingencies [Line Items]
Letter of credit facility	$ 8,885,000		$ 8,885,000
Car Offer
Commitments And Contingencies [Line Items]
Business acquisition, percentage of interest acquired	51%		51%				51%
Guarantees, description			provides certain guarantees to dealers through products such as its 45-Day Guarantee and OfferGuard service offerings on the CarOffer platform, which are accounted for under ASC Topic 460, Guarantees.
Number of days guarantee period | Days			45
Call Option | Car Offer
Commitments And Contingencies [Line Items]
Business acquisition, option to acquire remaining percentage of interest	25%		25%

Commitments and Contingencies_2

Commitments and Contingencies - Summary of Future Minimum Lease Payments (Details) $ in Thousands	Jun. 30, 2023 USD ($)
Commitments and Contingencies Disclosure [Abstract]
Remainder of 2023	$ 5,974
2024	15,922
2025	18,592
2026	22,334
2027	22,742
Thereafter	231,155
Total lease payments	316,719
Less imputed interest	(109,665)
Total	$ 207,054

Commitments and Contingencies_3

Commitments and Contingencies - Schedule of Future Minimum Sublease Income Payments (Details) $ in Thousands	Jun. 30, 2023 USD ($)
Commitments and Contingencies Disclosure [Abstract]
Remainder of 2023	$ 1,120
2024	1,951
2025	1,023
Total	$ 4,094

Stock-based Compensation and _3

Stock-based Compensation and Common Stock Share Repurchases - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 08, 2022
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Capitalized website development and internal-use software costs excluded from stock-based compensation expense	$ 1,292	$ 1,265	$ 2,437	$ 2,471
Payment of withholding taxes on net share settlements of restricted stock units	(4,828)		(6,894)	(11,260)
Unpaid withholding taxes on net share settlement of restricted stock units	368		3,958
Employee tax withholding requirements for net share settlements of equity awards	$ 5,196	$ 5,830	$ 10,852	$ 11,260
Number of shares repurchased and retired	1,311,387		5,301,248
Share repurchased and retired, value	$ 21,968		$ 87,119
Share repurchased and retired at average cost price per share	$ 16.75		$ 16.43
Class A Common Stock
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Employee tax withholding requirements and option costs due to net share settlement	240,674	147,533	576,122	303,269
Remaining value of authorized shares repurchased	$ 144,190		$ 144,190
Class A Common Stock | Maximum
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Aggregate share repurchase price					$ 250,000
CO Incentive Units and Subject Units
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Decrease in stock-based compensation expense	$ 11,800		$ 25,495

Stock-based Compensation and _4

Stock-based Compensation and Common Stock Share Repurchases - Summary of Stock-based Compensation Expense by Award Type (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total	$ 15,827	$ 26,457	$ 30,804	$ 54,299
Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total	590	646	1,204	1,290
Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total	14,012	12,786	28,375	26,289
CO Incentive Units and Subject Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total	$ 1,225	$ 13,025	$ 1,225	$ 26,720

Stock-based Compensation and _5

Stock-based Compensation and Common Stock Share Repurchases - Summary of Allocation of Stock-based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total	$ 15,827	$ 26,457	$ 30,804	$ 54,299
Cost of Revenue
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total	185	69	328	205
Sales and Marketing Expense
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total	2,872	4,086	5,956	8,069
Product, Technology, and Development Expense
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total	6,034	6,151	12,323	12,519
General and Administrative Expense
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total	$ 6,736	$ 16,151	$ 12,197	$ 33,506

Earnings Per Share - Additional

Earnings Per Share - Additional Information (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2023 shares	Jun. 30, 2022 shares	Jun. 30, 2023 Vote shares	Jun. 30, 2022 shares
Earnings Per Share Basic [Line Items]
Conversion of stock, description			Each share of Class B common stock is convertible into one share of Class A common stock at the option of the holder at any time or automatically upon certain events described in the Company’s amended and restated certificate of incorporation, including upon either the death or voluntary termination of the Company’s Executive Chairman.
Undistributed earnings ratio used to calculate allocation to class of stock			100%
Market Based Performance Award RSU
Earnings Per Share Basic [Line Items]
Potentially dilutive common stock equivalents excluded from calculation of diluted weighted-average shares outstanding			0	0
Class A Common Stock
Earnings Per Share Basic [Line Items]
Right to voting			one vote per share
Number of votes entitled to stockholders per share | Vote			1
Conversion of stock	0	0	0	0
Class B Common Stock
Earnings Per Share Basic [Line Items]
Right to voting			ten votes per share
Number of votes entitled to stockholders per share | Vote			10
Class of share converted to another class			one share of Class A common stock
Conversion of stock			1

Earnings Per Share - Schedule o

Earnings Per Share - Schedule of Reconciliation of Numerator and Denominator Used in Calculation of Basic and Diluted Net Income Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Numerator:
Consolidated net income	$ 13,817	$ 18,061	$ 25,683	$ 36,899
Net loss attributable to redeemable noncontrolling interest	(2,596)	(1,223)	(6,862)	(2,295)
Accretion of redeemable noncontrolling interest to redemption value		29,620		111,620
Net income (loss) attributable to common stockholders - basic	16,413	(10,336)	32,545	(72,426)
Net loss attributable to redeemable noncontrolling interest	(2,596)		(6,862)
Net income (loss) attributable to common stockholders - diluted	$ 13,817	$ (10,336)	$ 25,683	$ (72,426)
Denominator:
Weighted-average number of shares of common stock used in computing net income per share attributable to common stockholders — basic	113,438,057	118,390,641	114,392,961	118,211,975
Dilutive effect of share equivalents resulting from stock options	226,406		228,043
Dilutive effect of share equivalents resulting from unvested restricted stock units	826,188		576,886
Weighted-average number of shares of common stock used in computing net income per share attributable to common stockholders — diluted	114,490,651	118,390,641	115,197,890	118,211,975
Net income (loss) per share attributable to common stockholders:
Basic	$ 0.14	$ (0.09)	$ 0.28	$ (0.61)
Diluted	$ 0.12	$ (0.09)	$ 0.22	$ (0.61)

Earnings Per Share - Schedule_2

Earnings Per Share - Schedule of Potentially Dilutive Common Stock Equivalents Excluded from Calculation of Diluted Weighted-average Shares Outstanding (Details) - shares	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Stock Options Outstanding
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potentially dilutive common stock equivalents excluded from calculation of diluted weighted-average shares outstanding	558,080	885,547	559,054	914,870
Restricted Stock Units Outstanding
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potentially dilutive common stock equivalents excluded from calculation of diluted weighted-average shares outstanding	2,291,538	4,296,625	2,749,365	4,186,653
CO Incentive Units, Subject Units and noncontrolling interest
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potentially dilutive common stock equivalents excluded from calculation of diluted weighted-average shares outstanding		15,205,940		11,498,025

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Income Tax Examination [Line Items]
Income tax provision (benefit)	$ 8,601	$ 5,325	$ 15,132	$ 13,027
Effective income tax rate	34.40%	21.60%	31.70%	25%
Statutory tax rate	21%	21%	21%	21%
Revenue Commissioners, Ireland | Foreign
Income Tax Examination [Line Items]
Open tax year			2017
Internal Revenue Service (IRS)
Income Tax Examination [Line Items]
Open tax year			2018

Segment and Geographic Inform_3

Segment and Geographic Information - Additional Information (Details) - Segment	3 Months Ended	6 Months Ended	9 Months Ended
	Dec. 31, 2022	Jun. 30, 2023	Sep. 30, 2022
Segment Reporting Information [Line Items]
Number of reportable segments	2	2	1

Segment and Geographic Inform_4

Segment and Geographic Information - Summary of Segment Revenue, Income (Loss) and Depreciation and Amortization (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Segment Reporting Information [Line Items]
Total Revenue	$ 239,737	$ 511,229	$ 471,700	$ 941,837
Income (Loss) from Operations	17,738	23,542	31,797	50,201
Depreciation and Amortization	11,667	11,234	23,243	22,419
U.S. Marketplace
Segment Reporting Information [Line Items]
Total Revenue	158,443	152,753	314,064	304,642
Income (Loss) from Operations	24,619	28,346	51,158	58,182
Depreciation and Amortization	2,823	2,879	5,563	5,819
Digital Wholesale
Segment Reporting Information [Line Items]
Total Revenue	68,787	347,303	133,623	614,622
Income (Loss) from Operations	(6,307)	(2,638)	(17,532)	(4,749)
Depreciation and Amortization	8,701	8,257	17,394	16,379
Other
Segment Reporting Information [Line Items]
Total Revenue	12,507	11,173	24,013	22,573
Income (Loss) from Operations	(574)	(2,166)	(1,829)	(3,232)
Depreciation and Amortization	$ 143	$ 98	$ 286	$ 221

Segment and Geographic Inform_5

Segment and Geographic Information - Summary of Reconciliation Between Segment Income from Operations (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Segment Reporting [Abstract]
Total segment income from operations	$ 17,738	$ 23,542	$ 31,797	$ 50,201
Other income (expense), net	4,680	(156)	9,018	(275)
Income before income taxes	$ 22,418	$ 23,386	$ 40,815	$ 49,926

Segment and Geographic Inform_6

Segment and Geographic Information - Summary of Assets by Segment (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022	[1]
Segment Reporting Information [Line Items]
Total assets	$ 1,040,321	$ 927,102
U.S. Marketplace
Segment Reporting Information [Line Items]
Total assets	656,728	525,103
Digital Wholesale
Segment Reporting Information [Line Items]
Total assets	334,712	358,289
Other
Segment Reporting Information [Line Items]
Total assets	$ 48,881	$ 43,710
[1] As of December 31, 2022, Digital Wholesale assets did not reflect certain Dealer-to-Dealer and IMCO related capitalized website development assets from the U.S. Marketplace segment. During the three months ended March 31, 2023, the Company updated Digital Wholesale assets to reflect certain Dealer-to-Dealer and IMCO related capitalized website development amortization assets from the U.S. Marketplace segment and accordingly updated Digital Wholesale assets as of December 31, 2022 for comparative purposes.

Segment and Geographic Inform_7

Segment and Geographic Information - Summary of Revenue by Geographic Region (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Revenue by Geographic Region:
Total Revenue	$ 239,737	$ 511,229	$ 471,700	$ 941,837
United States
Revenue by Geographic Region:
Total Revenue	227,230	500,056	447,687	919,264
International
Revenue by Geographic Region:
Total Revenue	$ 12,507	$ 11,173	$ 24,013	$ 22,573