Redfin (RDFN) 10-Q 4 Nov 21 2021 Q3 Quarterly report Financial data

Cover Page

Cover Page - shares	9 Months Ended
	Sep. 30, 2021	Oct. 28, 2021
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2021
Document Transition Report	false
Entity File Number	001-38160
Entity Registrant Name	Redfin Corporation
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	74-3064240
Entity Address, Address Line One	1099 Stewart Street
Entity Address, Address Line Two	Suite 600
Entity Address, City or Town	Seattle
Entity Address, State or Province	WA
Entity Address, Postal Zip Code	98101
City Area Code	(206)
Local Phone Number	576-8333
Title of 12(b) Security	Common Stock, $0.001 par value per share
Trading Symbol	RDFN
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		105,481,348
Entity Central Index Key	0001382821
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q3
Amendment Flag	false

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Current assets
Cash and cash equivalents	$ 562,714	$ 925,276
Restricted cash	74,532	20,544
Short-term investments	28,578	131,561
Accounts receivable, net of allowances for credit losses	91,932	54,719
Inventory	435,144	49,158
Loans held for sale	42,762	42,539
Prepaid expenses	19,155	12,131
Other current assets	8,537	4,898
Total current assets	1,263,354	1,240,826
Property and equipment, net	55,535	43,988
Right-of-use assets, net	55,757	44,149
Long-term investments	53,488	11,922
Goodwill	407,228	9,186
Intangibles, net	194,856	1,830
Other assets, noncurrent	13,129	8,619
Total assets	2,043,347	1,360,520
Current liabilities
Accounts payable	10,075	5,644
Accrued liabilities	102,027	69,460
Other payables	16,766	13,184
Warehouse credit facilities	39,825	39,029
Secured revolving credit facility	199,627	23,949
Convertible senior notes, net	23,243	22,482
Lease liabilities	14,793	11,973
Total current liabilities	406,356	185,721
Lease liabilities, noncurrent	57,759	49,339
Convertible senior notes, net, noncurrent	1,212,767	488,268
Payroll tax liabilities, noncurrent	7,841	6,812
Deferred tax liabilities	883	0
Total liabilities	1,685,606	730,140
Commitments and contingencies (Note 8)
Series A convertible preferred stock	39,857	39,823
Stockholders’ equity
Common stock—par value $0.001 per share; 500,000,000 shares authorized; 105,375,935 and 103,000,594 shares issued and outstanding at September 30, 2021 and December 31, 2020, respectively	105	103
Additional paid-in capital	662,894	860,556
Accumulated other comprehensive income	47	211
Accumulated deficit	(345,162)	(270,313)
Total stockholders’ equity	317,884	590,557
Total liabilities, mezzanine equity, and stockholders’ equity	$ 2,043,347	$ 1,360,520

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Statement of Financial Position [Abstract]
Allowance for credit loss	$ 933	$ 160
Temporary equity, par value (in dollars per share)	$ 0.001	$ 0.001
Temporary equity, shares authorized (in shares)	10,000,000	10,000,000
Temporary equity, shares issued (in shares)	40,000	40,000
Temporary equity, shares outstanding (in shares)	40,000	40,000
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, authorized (in shares)	500,000,000	500,000,000
Common stock, issued (in shares)	105,375,935	103,000,594
Common stock, outstanding (in shares)	105,375,935	103,000,594

Consolidated Statements of Comp

Consolidated Statements of Comprehensive (Loss) Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Revenue	$ 540,074	$ 236,916	$ 1,279,708	$ 641,576
Cost of revenue	412,772	143,844	983,912	489,586
Gross profit	127,302	93,072	295,796	151,990
Operating expenses
Technology and development	43,658	22,452	112,824	60,687
Marketing	49,143	12,421	116,343	47,611
General and administrative	54,395	21,190	151,352	68,539
Total operating expenses	147,196	56,063	380,519	176,837
(Loss) Income from operations	(19,894)	37,009	(84,723)	(24,847)
Interest income	178	319	472	1,859
Interest expense	(3,672)	(2,522)	(7,822)	(7,631)
Income tax benefit	311	0	5,363	0
Other income (expense), net	4,128	(640)	4,099	(1,943)
Net (loss) income	(18,949)	34,166	(82,611)	(32,562)
Dividends on convertible preferred stock	(1,662)	(1,530)	(5,875)	(2,814)
Undistributed earnings attributable to participating securities	0	(653)	0	0
Net loss attributable to common stock - basic	(20,611)	31,983	(88,486)	(35,376)
Net loss attributable to common stock - diluted	$ (20,611)	$ 31,983	$ (88,486)	$ (35,376)
Net loss per share attributable to common stock - basic (in dollars per share)	$ (0.20)	$ 0.32	$ (0.85)	$ (0.36)
Weighted average shares - basic (in shares)	105,144,872	99,840,144	104,327,614	97,365,122
Weighted averages shares - diluted (in shares)	105,144,872	107,607,711	104,327,614	97,365,122
Net loss per share attributable to common stock - diluted (in dollars per share)	$ (0.20)	$ 0.30	$ (0.85)	$ (0.36)
Net loss	$ (18,949)	$ 34,166	$ (82,611)	$ (32,562)
Other comprehensive income (loss)
Foreign currency translation adjustments	3	6	3	(16)
Unrealized gain (loss) on available-for-sale debt securities	27	(139)	161	282
Comprehensive (loss) income	(18,919)	34,033	(82,447)	(32,296)
Service
Revenue	301,657	217,280	776,120	469,893
Cost of revenue	174,267	122,583	486,880	314,842
Product
Revenue	238,417	19,636	503,588	171,683
Cost of revenue	$ 238,505	$ 21,261	$ 497,032	$ 174,744

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Operating Activities
Net loss	$ (82,611)	$ (32,562)
Adjustments to reconcile net loss to net cash (used in) provided by operating activities:
Depreciation and amortization	32,303	10,581
Stock-based compensation	39,438	25,764
Amortization of debt discount and issuance costs	3,583	5,254
Non-cash lease expense	8,510	6,821
Impairment costs	0	2,063
Net loss (gain) on IRLCs, forward sales commitments, and loans held for sale	342	(2,303)
Other	(3,847)	(306)
Change in assets and liabilities:
Accounts receivable, net	(29,487)	(21,862)
Inventory	(385,986)	49,597
Prepaid expenses and other assets	(9,532)	7,396
Accounts payable	616	851
Accrued liabilities, other payables, deferred tax liabilities, and payroll tax liabilities, noncurrent	23,011	28,157
Lease liabilities	(9,644)	(8,368)
Origination of loans held for sale	(745,703)	(479,153)
Proceeds from sale of loans originated as held for sale	744,886	459,605
Net cash (used in) provided by operating activities	(414,121)	51,535
Investing activities
Purchases of property and equipment	(20,575)	(10,391)
Purchases of investments	(129,277)	(135,118)
Sales of investments	98,687	6,583
Maturities of investments	96,303	82,772
Cash paid for acquisition	(608,000)	0
Net cash used in investing activities	(562,862)	(56,154)
Financing activities
Proceeds from the issuance of convertible preferred stock, net of issuance costs	0	39,801
Proceeds from the issuance of common stock, net of issuance costs	0	69,701
Proceeds from the issuance of common stock pursuant to employee equity plans	14,194	15,119
Tax payments related to net share settlements on restricted stock units	(21,088)	(10,987)
Borrowings from warehouse credit facilities	710,535	473,283
Repayments to warehouse credit facilities	(709,739)	(454,277)
Borrowings from secured revolving credit facility	431,717	57,378
Repayments to secured revolving credit facility	(256,039)	(46,899)
Proceeds from issuance of convertible senior notes, net of issuance costs	561,529	0
Purchases of capped calls related to convertible senior notes	(62,647)	0
Payments for repurchases and conversions of convertible senior notes	(2,159)	0
Other payables—deposits held in escrow	3,161	2,097
Principal payments under finance lease obligations	(567)	(59)
Cash paid for secured revolving credit facility issuance costs	(485)	(4)
Net cash provided by financing activities	668,412	145,153
Effect of exchange rate changes on cash, cash equivalents, and restricted cash	(3)	(16)
Net change in cash, cash equivalents, and restricted cash	(308,574)	140,518
Cash, cash equivalents, and restricted cash:
Beginning of period	945,820	247,448
End of period	637,246	387,966
Supplemental disclosure of cash flow information
Cash paid for interest	5,539	3,001
Non-cash transactions
Stock-based compensation capitalized in property and equipment	2,745	1,714
Property and equipment additions in accounts payable and accrued liabilities	0	973
Leasehold improvements paid directly by lessor	$ 1,334	$ 37

Consolidated Statements of Chan

Consolidated Statements of Changes in Mezzanine Equity and Stockholders’ Equity - USD ($) $ in Thousands	Total	Revision of Prior Period, Accounting Standards Update, Adjustment	Series A Convertible Preferred Stock	Common Stock	Additional Paid-in Capital	Additional Paid-in CapitalRevision of Prior Period, Accounting Standards Update, Adjustment	Accumulated Deficit	Accumulated DeficitRevision of Prior Period, Accounting Standards Update, Adjustment	Accumulated Other Comprehensive Income/(Loss)
Beginning balance (in shares) at Dec. 31, 2019				93,001,597
Beginning balance at Dec. 31, 2019	$ 331,446			$ 93	$ 583,097		$ (251,786)		$ 42
Increase (Decrease) in Stockholders' Equity
Common Stock Dividends, Shares				30,640
Issuance of common stock, net (in shares)				4,484,305
Issuance of common stock, net	69,701			$ 4	69,697
Issuance of common stock pursuant to employee stock purchase program (in shares)				186,925
Issuance of common stock pursuant to employee stock purchase program	3,436				3,436
Issuance of common stock pursuant to exercise of stock options (in shares)				1,825,684
Issuance of common stock pursuant to exercise of stock options	11,502			$ 2	11,500
Issuance of common stock pursuant to settlement of restricted stock units (in shares)				1,017,675
Issuance of common stock pursuant to settlement of restricted stock units	0			$ 1	(1)
Common stock surrendered for employees' tax liability upon settlement of restricted stock units (in shares)				(305,410)
Common stock surrendered for employees' tax liability upon settlement of restricted stock units	(10,987)				(10,987)
Stock-based compensation	27,477				27,477
Other comprehensive loss	266								266
Net (loss) income	(32,562)						(32,562)
Ending balance (in shares) at Sep. 30, 2020				100,241,416
Ending balance at Sep. 30, 2020	400,279			$ 100	684,219		(284,348)		308
Beginning balance (in shares) at Dec. 31, 2019			0
Beginning balance at Dec. 31, 2019			$ 0
Increase (Decrease) in Temporary Equity [Roll Forward]
Issuance of convertible preferred stock, net (in shares)			40,000
Issuance of convertible preferred stock, net			$ 39,812
Ending balance (in shares) at Sep. 30, 2020			40,000
Ending balance at Sep. 30, 2020			$ 39,812
Beginning balance (in shares) at Jun. 30, 2020				99,394,432
Beginning balance at Jun. 30, 2020	355,260			$ 99	673,234		(318,514)		441
Increase (Decrease) in Stockholders' Equity
Common Stock Dividends, Shares				30,640
Issuance of common stock pursuant to exercise of stock options (in shares)				567,854
Issuance of common stock pursuant to exercise of stock options	3,998			$ 1	3,997
Issuance of common stock pursuant to settlement of restricted stock units (in shares)				353,160
Common stock surrendered for employees' tax liability upon settlement of restricted stock units (in shares)				(104,670)
Common stock surrendered for employees' tax liability upon settlement of restricted stock units	(4,922)
Stock-based compensation	11,910				11,910
Other comprehensive loss	(133)								(133)
Net (loss) income	34,166						34,166
Ending balance (in shares) at Sep. 30, 2020				100,241,416
Ending balance at Sep. 30, 2020	$ 400,279			$ 100	684,219		(284,348)		308
Beginning balance (in shares) at Jun. 30, 2020			40,000
Beginning balance at Jun. 30, 2020			$ 39,801
Increase (Decrease) in Temporary Equity [Roll Forward]
Issuance of convertible preferred stock, net			$ 11
Ending balance (in shares) at Sep. 30, 2020			40,000
Ending balance at Sep. 30, 2020			$ 39,812
Beginning balance (in shares) at Dec. 31, 2020	103,000,594			103,000,594
Beginning balance at Dec. 31, 2020	$ 590,557	$ (162,478)		$ 103	860,556	$ (170,240)	(270,313)	$ 7,762	211
Increase (Decrease) in Stockholders' Equity
Common Stock Dividends, Shares				91,920
Issuance of common stock pursuant to employee stock purchase program (in shares)				135,426
Issuance of common stock pursuant to employee stock purchase program	$ 7,299				7,299
Issuance of common stock pursuant to exercise of stock options (in shares)	1,354,078			1,354,078
Issuance of common stock pursuant to exercise of stock options	$ 6,896			$ 1	6,895
Issuance of common stock pursuant to settlement of restricted stock units (in shares)				1,072,378
Issuance of common stock pursuant to settlement of restricted stock units	0			$ 1	(1)
Common stock surrendered for employees' tax liability upon settlement of restricted stock units (in shares)				(319,229)
Common stock surrendered for employees' tax liability upon settlement of restricted stock units	(21,088)				(21,088)
Purchases of capped calls related to convertible senior notes	(62,647)				(62,647)
Issuance of common stock in connection with conversion of convertible senior notes (in shares)				40,768
Issuance of common stock in connection with conversion of convertible senior notes	(63)				(63)
Stock-based compensation	42,183				42,183
Other comprehensive loss	(164)								(164)
Net (loss) income	$ (82,611)						(82,611)
Ending balance (in shares) at Sep. 30, 2021	105,375,935			105,375,935
Ending balance at Sep. 30, 2021	$ 317,884			$ 105	662,894		(345,162)		47
Beginning balance (in shares) at Dec. 31, 2020	40,000		40,000
Beginning balance at Dec. 31, 2020	$ 39,823		$ 39,823
Increase (Decrease) in Temporary Equity [Roll Forward]
Issuance of convertible preferred stock, net			$ 34
Ending balance (in shares) at Sep. 30, 2021	40,000		40,000
Ending balance at Sep. 30, 2021	$ 39,857		$ 39,857
Beginning balance (in shares) at Jun. 30, 2021				104,838,095
Beginning balance at Jun. 30, 2021	325,596			$ 105	651,627		(326,213)		77
Increase (Decrease) in Stockholders' Equity
Common Stock Dividends, Shares				30,640
Issuance of common stock pursuant to exercise of stock options (in shares)				264,875
Issuance of common stock pursuant to exercise of stock options	1,696			$ 0	1,696
Issuance of common stock pursuant to settlement of restricted stock units (in shares)				334,283
Common stock surrendered for employees' tax liability upon settlement of restricted stock units (in shares)				(95,122)
Common stock surrendered for employees' tax liability upon settlement of restricted stock units	(4,558)				(4,558)
Issuance of common stock in connection with conversion of convertible senior notes (in shares)				3,164
Issuance of common stock in connection with conversion of convertible senior notes	(10)				(10)
Stock-based compensation	14,139				14,139
Other comprehensive loss	(30)								(30)
Net (loss) income	$ (18,949)						(18,949)
Ending balance (in shares) at Sep. 30, 2021	105,375,935			105,375,935
Ending balance at Sep. 30, 2021	$ 317,884			$ 105	$ 662,894		$ (345,162)		$ 47
Beginning balance (in shares) at Jun. 30, 2021			40,000
Beginning balance at Jun. 30, 2021			$ 39,846
Increase (Decrease) in Temporary Equity [Roll Forward]
Issuance of convertible preferred stock, net	$ 0		$ 11
Ending balance (in shares) at Sep. 30, 2021	40,000		40,000
Ending balance at Sep. 30, 2021	$ 39,857		$ 39,857

Summary of Accounting Policies

Summary of Accounting Policies	9 Months Ended
	Sep. 30, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Summary of Accounting Policies	Summary of Accounting Policies Basis of Presentation —The consolidated financial statements and accompanying notes have been prepared in accordance with generally accepted accounting principles in the United States of America (“GAAP”). The financial information as of December 31, 2020 that is included in this quarterly report is derived from the audited consolidated financial statements and notes for the year ended December 31, 2020 included in Item 8 in our annual report for the year ended December 31, 2020. Such financial information should be read in conjunction with the notes and management’s discussion and analysis of the consolidated financial statements included in our annual report. The unaudited consolidated interim financial statements, in the opinion of management, reflect all adjustments, consisting only of normal recurring adjustments, necessary to present fairly our financial position as of September 30, 2021, our statements of comprehensive (loss) income, and statements of changes in mezzanine equity and stockholders’ equity for the three and nine months ended September 30, 2021 and 2020, as well as our statements of cash flows for the nine months ended September 30, 2021 and 2020. The results for the three and nine months ended September 30, 2021 are not necessarily indicative of the results to be expected for the year ending December 31, 2021 or for any interim period or for any other future year. Certain amounts presented in the prior period consolidated statements of cash flows have been reclassified to conform to the current period financial statement presentation. The change in classification does not affect previously reported cash flows from operating activities, investing activities, or financing activities in the consolidated statements of cash flows. Principles of Consolidation —The unaudited consolidated interim financial statements include the accounts of Redfin Corporation and its wholly owned subsidiaries, including those entities in which we have a variable interest and of which we are the primary beneficiary. Intercompany transactions and balances have been eliminated. Use of Estimates —The preparation of consolidated financial statements, in conformity with GAAP, requires our management to make estimates and assumptions that affect the reported amounts of assets and liabilities and results of operations during the respective periods. Our estimates include, but are not limited to, the valuation of deferred income taxes, stock-based compensation, net realizable value of inventory, capitalization of website and software development costs, the incremental borrowing rate for the determination of the present value of lease payments, recoverability of intangible assets with finite lives, fair value of our mortgage loans held for sale, fair value of interest rate lock commitments, and forward sales commitments, fair value of reporting units for purposes of evaluating goodwill for impairment, current expected credit losses on certain financial assets, the fair value of the convertible feature related to our convertible senior notes, and the fair value of assets acquired and liabilities assumed in connection with our acquisition of RentPath. The amounts ultimately realized from the affected assets or ultimately recognized as liabilities will depend on, among other factors, general business conditions and could differ materially in the near term from the carrying amounts reflected in the consolidated financial statements. Convertible Senior Notes —In accounting for the issuance of our convertible senior notes, we treat the instrument wholly as a liability, in accordance with the adoption of ASU 2020-06, Debt—Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging—Contracts in Entity's Own Equity (Subtopic 815-40): Accounting for Convertible Instruments and Contracts in an Entity's Own Equity ("ASU 2020-06"). Issuance costs are being amortized to expense over the respective term of the convertible senior notes. For conversions prior to the maturity of the notes, we will settle using cash, shares of our common stock, or a combination of cash and shares of our common stock, at our election. The carrying amount of the instrument (including unamortized debt issuance costs) is reduced by cash and other assets transferred, with the difference reflected as a reduction to additional paid-in capital. The indentures governing our convertible senior notes allow us, under certain circumstances, to irrevocably fix our method for settling conversions of the applicable notes by giving notice to the noteholders. Our election to irrevocably fix the settlement method could affect the calculation of diluted earnings per share when applicable. We have no plans to exercise our rights to fix the settlement method. Rentals Revenue —Due to our acquisition of RentPath, we now record rentals revenue which is primarily composed of subscription-based product offerings for internet listing services, as well as lead management and digital marketing solutions. Rentals revenue is recorded as a component of service revenue in our consolidated statements of comprehensive (loss) income. Revenue is recognized upon transfer of control of promised service to customers over time in an amount that reflects the consideration we expect to receive in exchange for those services. Revenues from subscription-based services are recognized on a straight-line basis over the term of the contract, which generally have a term of less than one year. Revenue is presented net of sales allowances, which are not material. The transaction price for a contract is generally determined by the stated price in the contract, excluding any related sales taxes. We enter into contracts that can include various combinations of subscription services, which are capable of being distinct and accounted for as separate performance obligations. We allocate the transaction price to each performance obligation in the contract on a relative stand-alone selling price basis. Generally, the combinations of subscription services are fulfilled concurrently and are co-terminus. Our rentals contracts do not contain any refund provisions other than in the event of our non-performance or breach. Recently Adopted Accounting Pronouncements —In August 2020, the Financial Accounting Standards Board (the "FASB") issued authoritative guidance under ASU 2020-06. This guidance removes the liability and equity separation models for convertible instruments with a cash conversion feature or beneficial conversion feature. As a result, companies will more likely account for a convertible debt instrument wholly as debt, and for convertible preferred stock wholly as preferred stock (i.e., as a single unit of account). In addition, the guidance simplifies the settlement assessment that issuers perform to determine whether a contract in their own equity qualifies for equity classification. Finally, the guidance requires entities to use the if-converted method to calculate earnings per share for all convertible instruments. We early adopted ASU 2020-06 as of January 1, 2021 using the modified retrospective approach. The cumulative effect of initially applying the new standard was recognized as an adjustment to accumulated deficit. Upon the adoption of the new standard we recognized the following adjustments: Ending Balance as of December 31, 2020 ASU 2020-06 Adjustments Beginning Balance as of January 1, 2021 Convertible senior notes, net $ 22,482 $ 2,723 $ 25,205 Convertible senior notes, net, noncurrent 488,268 159,755 648,023 Additional paid-in capital 860,556 (170,240) 690,316 Accumulated deficit (270,313) 7,762 (262,551) The $7,762 adjustment to accumulated deficit represents a reduction to non-cash interest expense related to the accretion of the debt discount under the historical separation model.

Business Combinations

Business Combinations	9 Months Ended
	Sep. 30, 2021
Business Combination and Asset Acquisition [Abstract]
Business Combinations	Business Combinations On April 2, 2021, we acquired, for $608,000 in cash, all of the equity interests of RentPath Holdings, Inc., as reorganized following an internal restructuring of the entity and certain of its wholly owned subsidiaries (as reorganized, "RentPath" and such acquisition, the "Acquisition"). In connection with the internal restructuring, certain assets and liabilities related to the business of providing digital media services to clients in the residential real estate business were transferred to RentPath, and the remaining assets and liabilities were transferred to a wind-down company. We acquired RentPath to enter into the real estate rentals market. The results of operations and the fair values of the assets acquired and liabilities assumed have been included in the consolidated financial statements since the date of acquisition. RentPath is reported in our rentals segment in Note 3. During the three and nine months ended September 30, 2021, RentPath contributed $40,406 and $82,954 to revenue, respectively. The goodwill recognized in connection with our acquisition of RentPath is primarily attributable to the anticipated synergies from future growth of the combined business and is not expected to be deductible for tax purposes. We are currently evaluating the reporting unit allocation of goodwill. The following table summarizes the fair value of assets acquired and liabilities assumed as a result of the Acquisition. As of September 30, 2021, the amount allocated to the opening balance of deferred tax liabilities assumed in the Acquisition is provisional and subject to revision as more detailed analyses are completed and additional information about the amount of this balance becomes available: Cash and cash equivalents (1) $ 334 Accounts receivable 7,726 Prepaid expenses 5,483 Other current assets 416 Property and equipment, net 3,103 Operating lease right-of-use assets 12,330 Intangible assets 211,000 Goodwill 398,042 Total assets 638,434 Accounts payable (1,355) Accrued liabilities (1) (9,412) Lease liabilities (1,264) Lease liabilities and deposits, noncurrent (11,066) Payroll tax liabilities, noncurrent (1,030) Deferred tax liabilities (6,307) Total liabilities (30,434) Total purchase consideration $ 608,000 (1) On April 2, 2021, $334 of cash and cash equivalents owed to a wind-down company remained in RentPath's primary operating account due to the timing of bank transfers and wires. The cash and cash equivalents were recorded at fair value along with an offsetting due-to liability on April 2, 2021. Acquisition-related costs consisted of external fees for advisory, legal, and other professional services and totaled approximately $202 and $7,925 for the three and nine months ended September 30, 2021, respectively. These costs were expensed as incurred and recorded in general and administrative costs in our consolidated statements of comprehensive (loss) income. Identifiable Intangible Assets —The following table provides the fair values of the RentPath intangible assets, along with their estimated useful lives: Estimated Fair Value Estimated Useful Life Trade names $ 70,000 10 Developed technology 60,500 3 Customer relationships 80,500 10 Total 211,000 The identifiable intangible assets include trade names, developed technology (an application platform), and customer relationships. Trade names primarily relate to the RentPath brand. Developed technology relates to the RentPath website and mobile application, which are the primary channels for meeting customers. Customer relationships represent existing customer contracts. Unaudited Pro Forma Financial Information —The following table presents unaudited pro forma financial information for the three and nine months ended September 30, 2021. The pro forma financial information combines our results of operations with that of RentPath as though the companies had been combined as of January 1, 2020. The pro forma information is presented for informational purposes only and is not indicative of the results of operations that would have been achieved if the Acquisition had taken place at such time. The pro forma financial information presented below includes adjustments for bankruptcy costs, depreciation and amortization, provision for income taxes, transaction costs, and interest expense related to debt that would not have been incurred if we had consummated the Acquisition on January 1, 2020: Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Revenue $ 540,074 $ 284,275 $ 1,322,632 $ 790,662 Net (loss) income (18,792) 23,099 (94,335) (60,918) Material non-recurring adjustments made in the pro forma financial information disclosed above were $23 and $9,151 for the three months ended September 30, 2021 and 2020 and $76,118 and $48,224 for the nine months ended September 30, 2021 and 2020, respectively. These adjustments primarily relate to the reorganization costs that would not have been incurred if we had consummated the Acquisition on January 1, 2020 and decreased expense in the periods specified. These adjustments also include an income tax benefit resulting from the Acquisition, which assumes that we had consummated the Acquisition on January 1, 2020.

Segment Reporting and Revenue

Segment Reporting and Revenue	9 Months Ended
	Sep. 30, 2021
Segment Reporting [Abstract]
Segment Reporting and Revenue	Segment Reporting and Revenue In operation of the business, our management, including our chief operating decision maker ("CODM"), who is also our chief executive officer, evaluates the performance of our operating segments based on revenue and gross profit. We do not analyze discrete segment balance sheet information related to long-term assets, substantially all of which are located in the United States. All other financial information is presented on a consolidated basis. We have six operating segments and three reportable segments, real estate services, properties, and rentals. As a result of our acquisition of RentPath, we added the rentals segment and determined it is a reportable segment because RentPath met the quantitative thresholds under ASC 280, Segment Reporting. Our CODM evaluates the rentals segment as a stand-alone business; accordingly, we are separately reporting the segment's operating expenses from our consolidated operating expenses. We generate revenue primarily from commissions and fees charged on each real estate services transaction closed by our lead agents or partner agents, from the sale of homes, and from subscription-based product offerings for our rentals business. Our key revenue components are brokerage revenue, partner revenue, properties revenue, rentals revenue, and other revenue. Information on each of the reportable and other segments and reconciliation to consolidated net (loss) income is as follows: Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Revenue Real estate services (brokerage) $ 243,575 $ 194,375 $ 637,532 $ 425,269 Real estate services (partner) 14,220 15,478 41,070 28,269 Properties 238,417 19,005 503,588 170,287 Rentals 40,406 — 82,954 — Other 8,206 8,503 26,084 19,999 Intercompany eliminations (4,750) (445) (11,520) (2,248) Total $ 540,074 $ 236,916 $ 1,279,708 $ 641,576 Cost of revenue Real estate services 161,449 117,944 453,790 300,305 Properties 238,397 20,460 496,948 173,107 Rentals 7,395 — 14,965 — Other 10,281 5,885 29,729 18,422 Intercompany eliminations (4,750) (445) (11,520) (2,248) Total $ 412,772 $ 143,844 $ 983,912 $ 489,586 Gross profit Real estate services 96,346 91,909 224,812 153,233 Properties 20 (1,455) 6,640 (2,820) Rentals 33,011 — 67,989 — Other (2,075) 2,618 (3,645) 1,577 Total $ 127,302 $ 93,072 $ 295,796 $ 151,990 Real estate services, properties, and other operating expenses 96,910 56,063 281,569 176,837 Rentals operating expenses 50,286 — 98,950 — Interest income 178 319 472 1,859 Interest expense (3,672) (2,522) (7,822) (7,631) Income tax benefit 311 — 5,363 — Other income (expense), net 4,128 (640) 4,099 (1,943) Net (loss) income $ (18,949) $ 34,166 $ (82,611) $ (32,562)

Financial Instruments

Financial Instruments	9 Months Ended
	Sep. 30, 2021
Fair Value Disclosures [Abstract]
Financial Instruments	Financial Instruments Derivatives Our primary market exposure is to interest rate risk, specifically U.S. treasury and mortgage interest rates, due to their impact on mortgage-related assets and commitments. We use forward sales commitments on whole loans and mortgage-backed securities to manage and reduce this risk. We do not have any derivative instruments designated as hedging instruments. Forward Sales Commitments —We are exposed to interest rate and price risk on loans held for sale from the funding date until the date the loan is sold. Forward sales commitments on whole loans and mortgage-backed securities are used to fix the forward sales price that will be realized at the sale of each loan. Interest Rate Lock Commitments —Interest rate lock commitments ("IRLCs") represent an agreement to extend credit to a mortgage loan applicant. We commit (subject to loan approval) to fund the loan at the specified rate, regardless of changes in market interest rates between the commitment date and the funding date. Outstanding IRLCs are subject to interest rate risk and related price risk during the period from the date of commitment through the loan funding date or expiration date. Loan commitments generally range between 30 and 90 days and the borrower is not obligated to obtain the loan. Therefore, IRLCs are subject to fallout risk, which occurs when approved borrowers choose not to close on the underlying loans. We review our commitment-to-closing ratio ("pull-through rate") as part of an estimate of the number of mortgage loans that will fund according to the IRLCs. Notional Amounts September 30, 2021 December 31, 2020 Forward sales commitments $ 96,397 $ 130,109 IRLCs 94,301 88,923 The locations and amounts of gains (losses) recognized in income related to our derivatives are as follows: Three Months Ended September 30, Nine Months Ended September 30, Instrument Classification 2021 2020 2021 2020 Forward sales commitments Service revenue $ 859 $ 553 $ 938 $ 442 IRLCs Service revenue (888) (233) (687) 1,131 Fair Value of Financial Instruments In May 2020, we purchased preferred stock of Matterport, Inc. ("Matterport"), then a privately held company. In July 2021, Matterport became a publicly traded company through a business combination transaction with a special purpose acquisition vehicle. In connection with the transaction, we received Matterport's publicly traded Class A common stock in exchange for the preferred stock that we owned. We previously recorded our investment at cost because the preferred stock did not have a readily determinable fair value, but upon receipt of the publicly traded common stock, we recorded our investment at fair value. The increase in value is recorded in other income (expense), net in our consolidated statements of comprehensive (loss) income for the three and nine months ended September 30, 2021, and is included in adjustments to reconcile net loss to net cash used in operating activities, as a component of other, in our consolidated statement of cash flows for the nine months ended September 30, 2021. The balance is included in short-term investments in our consolidated balance sheets. A summary of assets and liabilities related to our financial instruments, measured at fair value on a recurring basis and as reflected in our consolidated balance sheets, is set forth below: Balance at September 30, 2021 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets Cash equivalents Money market funds $ 501,432 $ 501,432 $ — $ — Total cash equivalents 501,432 501,432 — — Short-term investments U.S. treasury securities 11,981 11,981 — — Agency bonds 11,912 11,912 — — Equity securities 4,685 4,685 — — Loans held for sale 42,762 — 42,762 — Other current assets Forward sales commitments 552 — 552 — IRLCs 1,146 — — 1,146 Total other current assets 1,698 — 552 1,146 Long-term investments U.S. treasury securities 53,488 53,488 — — Total assets $ 627,958 $ 583,498 $ 43,314 $ 1,146 Liabilities Accrued liabilities Forward sales commitments $ 87 $ — $ 87 $ — IRLCs 62 — — 62 Total liabilities $ 149 $ — $ 87 $ 62 Balance at December 31, 2020 Quoted Prices in Active Markets for Identical Assets Significant Significant Assets Cash equivalents Money market funds $ 886,261 $ 886,261 $ — $ — U.S. treasury securities 6,100 6,100 — — Total cash equivalents 892,361 892,361 — — Short-term investments U.S. treasury securities 131,561 131,561 — — Loans held for sale 42,539 — 42,539 — Other current assets Forward sales commitments 34 — 34 — IRLCs 1,781 — — 1,781 Total other current assets 1,815 — 34 1,781 Long-term investments Agency bonds 11,922 11,922 — — Total assets $ 1,080,198 $ 1,035,844 $ 42,573 $ 1,781 Liabilities Accrued liabilities Forward sales commitments $ 507 $ — $ 507 $ — IRLCs 10 — — 10 Total liabilities $ 517 $ — $ 507 $ 10 There were no transfers into or out of Level 3 financial instruments during the periods presented. The significant unobservable input used in the fair value measurement of IRLCs is the pull-through rate. Significant changes in the input could result in a significant change in fair value measurement. The pull-through rate used to determine the fair value of IRLCs was as follows: Key Inputs Valuation Technique September 30, 2021 December 31, 2020 Weighted-average pull-through rate Market pricing 71.7% 72.3% The following is a summary of changes in the fair value of IRLCs for the nine months ended September 30, 2021: Balance, net—January 1, 2021 $ 1,771 Issuances of IRLCs 14,523 Settlements of IRLCs (14,956) Net loss recognized in earnings (254) Balance, net—September 30, 2021 $ 1,084 Changes in fair value recognized during the period relating to assets still held at September 30, 2021 $ (687) The following table presents the carrying amounts and estimated fair values of our convertible senior notes that are not recorded at fair value on our consolidated balance sheets: September 30, 2021 December 31, 2020 Issuance Net Carrying Amount Estimated Fair Value Net Carrying Amount Estimated Fair Value 2023 notes $ 23,243 $ 38,980 $ 22,482 $ 59,894 2025 notes 650,093 660,556 488,268 802,083 2027 notes 562,674 516,856 — — The difference between the principal amounts of our 2023 notes, our 2025 notes, and our 2027 notes, which were $23,512, $661,250, and $575,000, respectively, and the net carrying amounts of the notes represents the unamortized debt issuance costs. See Note 16 for additional details. The estimated fair value of each tranche of convertible senior notes is based on the closing trading price of the notes on the last day of trading for the period, and is classified as Level 2 within the fair value hierarchy, due to the limited trading activity of the notes. As of September 30, 2021, the difference between the net carrying amount of the notes and their estimated fair values represented the notes' equity conversion premium. Based on the closing price of our common stock of $50.10 on September 30, 2021, the if-converted value of the 2023 notes exceeded the principal amount of $23,512, while the if-converted values of the 2025 notes and 2027 notes were less than the principal amounts of $661,250 and $575,000, respectively. See Note 16 for additional details on our convertible senior notes. See Note 12 for the carrying amount of our convertible preferred stock. Assets and liabilities recognized or disclosed at fair value on a nonrecurring basis include items such as property and equipment, goodwill and other intangible assets, and other assets. These assets are remeasured at fair value if determined to be impaired. The cost or amortized cost, gross unrealized gains and losses, and estimated fair market value of our cash, money market funds, restricted cash, available-for-sale investments, and equity securities were as follows: September 30, 2021 Cost or Amortized Cost Unrealized Gains Unrealized Losses Estimated Fair Value Cash, Cash Equivalents, Restricted Cash Short-term Investments Long-term Investments Cash $ 61,282 $ — $ — $ 61,282 $ 61,282 $ — $ — Money markets funds 501,432 — — 501,432 501,432 — — Restricted cash 74,532 — — 74,532 74,532 — — U.S. treasury securities 65,461 16 (8) 65,469 — 11,981 53,488 Agency bonds 11,900 12 — 11,912 — 11,912 — Equity securities 500 4,185 — 4,685 — 4,685 — Total $ 715,107 $ 4,213 $ (8) $ 719,312 $ 637,246 $ 28,578 $ 53,488 December 31, 2020 Cost or Amortized Cost Unrealized Gains Unrealized Losses Estimated Fair Value Cash, Cash Equivalents, Restricted Cash Short-term Investments Long-term Investments Cash $ 32,915 $ — $ — $ 32,915 $ 32,915 $ — $ — Money markets funds 886,261 — — 886,261 886,261 — — Restricted cash 20,544 — — 20,544 20,544 — — U.S. treasury securities 137,502 159 — 137,661 6,100 131,561 — Agency bonds 11,900 22 — 11,922 — — 11,922 Total $ 1,089,122 $ 181 $ — $ 1,089,303 $ 945,820 $ 131,561 $ 11,922 We have evaluated our portfolio of available-for-sale debt securities based on credit quality indicators for expected credit losses and do not believe there are any expected credit losses. Our portfolio consists of U.S. government securities, all with a high quality credit rating issued by various credit agencies. As of September 30, 2021 and December 31, 2020, we had accrued interest of $148 and $108, respectively, on our available-for-sale investments, of which we have recorded no expected credit losses. Accrued interest receivable is presented within other current assets in our consolidated balance sheets.

Inventory

Inventory	9 Months Ended
	Sep. 30, 2021
Inventory Disclosure [Abstract]
Inventory	Inventory The components of inventory were as follows: September 30, 2021 December 31, 2020 Properties for sale $ 170,731 $ 17,153 Properties not available for sale 38,835 7,225 Properties under improvement 225,578 24,780 Inventory $ 435,144 $ 49,158 Inventory includes direct home purchase costs and any capitalized improvements, net of inventory reserves, which reflect the lower of cost or net realizable value write-downs applied on a specific home basis. As of September 30, 2021 and December 31, 2020, our inventory reserves were $2,551 and $29, respectively. During the nine months ended September 30, 2021, we purchased 1,528 homes with an inventory value of $790,738 and sold 851 homes with an inventory value of $415,110. During the nine months ended September 30, 2020, we purchased 253 homes with an inventory value of $101,759 and sold 370 homes with an inventory value of $149,676.

Property and Equipment

Property and Equipment	9 Months Ended
	Sep. 30, 2021
Property, Plant and Equipment [Abstract]
Property and Equipment	Property and Equipment The components of property and equipment were as follows: Useful Lives (Years) September 30, 2021 December 31, 2020 Leasehold improvements Shorter of lease term or economic life $ 33,467 $ 29,558 Website and software development costs 2 - 3 46,014 33,278 Computer and office equipment 3 - 5 13,154 7,765 Software 3 1,871 1,858 Furniture 7 7,945 7,450 Property and equipment, gross 102,451 79,909 Accumulated depreciation and amortization (54,776) (41,614) Construction in progress 7,860 5,693 Property and equipment, net $ 55,535 $ 43,988 Depreciation and amortization expense for property and equipment amounted to $5,399 and $3,594 for the three months ended September 30, 2021 and 2020, respectively, and $14,369 and $10,215 for the nine months ended September 30, 2021 and 2020, respectively. We capitalized website and software development costs, including stock-based compensation, of $4,727 and $2,773 for the three months ended September 30, 2021 and 2020, respectively, and $13,137 and $8,286 for the nine months ended September 30, 2021 and 2020, respectively.

Leases

Leases	9 Months Ended
	Sep. 30, 2021
Leases [Abstract]
Leases	Leases We lease office space under noncancelable operating leases with original terms ranging from one Three Months Ended September 30, Nine Months Ended September 30, Lease Cost Classification 2021 2020 2021 2020 Operating lease cost: Operating lease cost (1) Cost of revenue $ 2,400 $ 2,123 $ 7,105 $ 6,405 Operating lease cost (1) Operating expenses 1,727 1,087 4,440 3,274 Total operating lease cost $ 4,127 $ 3,210 $ 11,545 $ 9,679 Finance lease cost: Amortization of right-of-use assets Cost of revenue $ 139 $ 2 $ 335 $ 7 Interest on lease liabilities Cost of revenue 21 17 51 51 Total finance lease cost $ 160 $ 19 $ 386 $ 58 (1) Includes lease expense with initial terms of twelve months or less of $430 and $218 for the three months ended September 30, 2021 and 2020, respectively, and $1,156 and $712 for the nine months ended September 30, 2021 and 2020, respectively. Lease Liabilities Other Leases Total Lease Obligations Maturity of Lease Liabilities Operating Financing Operating 2021, excluding the nine months ended September 30, 2021 $ 4,397 $ 120 $ 256 $ 4,773 2022 16,852 478 467 17,797 2023 15,779 465 — 16,244 2024 14,324 379 — 14,703 2025 11,189 80 — 11,269 Thereafter 16,929 — — 16,929 Total lease payments $ 79,470 $ 1,522 $ 723 $ 81,715 Less: Interest (1) 8,316 124 Present value of lease liabilities $ 71,154 $ 1,398 (1) Includes interest on operating leases of $2,788 and financing lease of $66 within the next twelve months. Lease Term and Discount Rate September 30, 2021 December 31, 2020 Weighted-average remaining operating lease term (years) 5.1 5.2 Weighted-average remaining finance lease term (years) 3.3 3.5 Weighted-average discount rate for operating leases 4.4 % 4.4 % Weighted-average discount rate for finance leases 5.4 % 5.4 % Nine Months Ended September 30, Supplemental Cash Flow Information 2021 2020 Cash paid for amounts included in the measurement of lease liabilities Operating cash flows from operating leases $ 12,006 $ 10,584 Operating cash flows from finance leases 64 7 Financing cash flows from finance leases 226 38 Right of use assets obtained in exchange for lease liabilities Operating leases $ 6,544 $ 354 Finance leases 987 —
Leases	Leases We lease office space under noncancelable operating leases with original terms ranging from one Three Months Ended September 30, Nine Months Ended September 30, Lease Cost Classification 2021 2020 2021 2020 Operating lease cost: Operating lease cost (1) Cost of revenue $ 2,400 $ 2,123 $ 7,105 $ 6,405 Operating lease cost (1) Operating expenses 1,727 1,087 4,440 3,274 Total operating lease cost $ 4,127 $ 3,210 $ 11,545 $ 9,679 Finance lease cost: Amortization of right-of-use assets Cost of revenue $ 139 $ 2 $ 335 $ 7 Interest on lease liabilities Cost of revenue 21 17 51 51 Total finance lease cost $ 160 $ 19 $ 386 $ 58 (1) Includes lease expense with initial terms of twelve months or less of $430 and $218 for the three months ended September 30, 2021 and 2020, respectively, and $1,156 and $712 for the nine months ended September 30, 2021 and 2020, respectively. Lease Liabilities Other Leases Total Lease Obligations Maturity of Lease Liabilities Operating Financing Operating 2021, excluding the nine months ended September 30, 2021 $ 4,397 $ 120 $ 256 $ 4,773 2022 16,852 478 467 17,797 2023 15,779 465 — 16,244 2024 14,324 379 — 14,703 2025 11,189 80 — 11,269 Thereafter 16,929 — — 16,929 Total lease payments $ 79,470 $ 1,522 $ 723 $ 81,715 Less: Interest (1) 8,316 124 Present value of lease liabilities $ 71,154 $ 1,398 (1) Includes interest on operating leases of $2,788 and financing lease of $66 within the next twelve months. Lease Term and Discount Rate September 30, 2021 December 31, 2020 Weighted-average remaining operating lease term (years) 5.1 5.2 Weighted-average remaining finance lease term (years) 3.3 3.5 Weighted-average discount rate for operating leases 4.4 % 4.4 % Weighted-average discount rate for finance leases 5.4 % 5.4 % Nine Months Ended September 30, Supplemental Cash Flow Information 2021 2020 Cash paid for amounts included in the measurement of lease liabilities Operating cash flows from operating leases $ 12,006 $ 10,584 Operating cash flows from finance leases 64 7 Financing cash flows from finance leases 226 38 Right of use assets obtained in exchange for lease liabilities Operating leases $ 6,544 $ 354 Finance leases 987 —

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2021
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Legal Proceedings Below is a discussion of our material, pending legal proceedings. Except as discussed below, we cannot estimate a range of reasonably possible losses given the preliminary stage of these proceedings and the claims and issues presented. In addition to the matters discussed below, from time to time, we are involved in litigation, claims, and other proceedings arising in the ordinary course of our business. Except for the matters discussed below, we do not believe that any of our pending litigation, claims, and other proceedings are material to our business. Lawsuit by David Eraker —On May 11, 2020, David Eraker, our co-founder and former chief executive officer who departed Redfin in 2006, filed a complaint through Appliance Computing III, Inc. (d/b/a Surefield) ("Surefield"), which is a company that Mr. Eraker founded and that we believe he controls, in the U.S. District Court for the Western District of Texas, Waco Division. The complaint alleges that we are infringing patents claimed to be owned by Surefield without its authorization or license. Surefield is seeking an unspecified amount of damages and an injunction against us offering products and services that allegedly infringe the patents at issue. On July 15, 2020, we filed a counterclaim against Surefield to allege that (i) we are not infringing on the patents that Surefield has alleged that we are infringing and (ii) the patents claimed by Surefield are invalid. This counterclaim asks the court to declare judgment in our favor. Lawsuit Alleging Violations of the Fair Housing Act —On October 28, 2020, a group of ten organizations filed a complaint against us in the U.S. District Court for the Western District of Washington. The organizations are the National Fair Housing Alliance, the Fair Housing Center of Metropolitan Detroit, the Fair Housing Justice Center, the Fair Housing Rights Center in Southeastern Pennsylvania, the HOPE Fair Housing Center, the Lexington Fair Housing Council, the Long Island Housing Services, the Metropolitan Milwaukee Fair Housing Council, Open Communities, and the South Suburban Housing Center. The complaint alleges that certain of our business policies and practices violate provisions of the Fair Housing Act (the “FHA”). The plaintiffs allege that these policies and practices (i) have the effect of our services being unavailable in predominantly non-white communities on a more frequent basis than predominantly white communities and (ii) are unnecessary to achieve a valid interest or legitimate objective. The complaint focuses on the following policies and practices, as alleged by the plaintiffs: (i) a home's price must exceed a certain dollar amount before we offer service through one of our lead agents or partner agents and (ii) our services and pricing structures are available only for homes serviced by one of our lead agents and those same services and pricing structures may not be offered by one of our partner agents. The plaintiffs seek (i) a declaration that our alleged policies and practices violate the FHA, (ii) an order enjoining us from further alleged violations, (iii) an unspecified amount of monetary damages, and (iv) payment of plaintiffs’ attorneys' fees and costs. Lawsuits Alleging Misclassification —On August 28, 2019, Devin Cook, who is one of our former independent contractor licensed sales associates, whom we call associate agents, filed a complaint against us in the Superior Court of California, County of San Francisco. The plaintiff initially pled the complaint as a class action and alleged that we misclassified her as an independent contractor instead of an employee. The plaintiff also sought representative claims under California’s Private Attorney General Act ("PAGA"). On January 30, 2020, the plaintiff filed a first amended complaint dismissing her class action claim and asserting only claims under PAGA. On September 24, 2021, the court denied our motion for summary judgment to dismiss the plaintiff’s remaining claims under PAGA, holding that at this stage of the proceeding, we had not proved that we properly classified associate agents as independent contractors under California law. The plaintiff continues to seek unspecified penalties for alleged violations of PAGA. On November 20, 2020, Jason Bell, who is one of our former lead agents as well as a former associate agent, filed a complaint against us in the U.S. District Court for the Southern District of California. The complaint is pled as a class action and alleges that, (1) during the time he served as an associate agent, we misclassified him as an independent contractor instead of an employee and (2) during the time he served as a lead agent, we misclassified him as an employee who was exempt from minimum wage and overtime laws. The plaintiff also asserts representative claims under PAGA. The plaintiff is seeking unspecified amounts of unpaid overtime wages, regular wages, meal and rest period compensation, waiting time and other penalties, injunctive and other equitable relief, and plaintiff's attorneys' fees and costs. On August 12, 2021, the court granted our motion to compel arbitration on the plaintiff’s non-PAGA claims and stayed the plaintiff’s PAGA claims pending resolution of the arbitration. On March 24, 2021, Anthony Bush, who is one of our former associate agents, filed a complaint against us in the Superior Court of California, County of Alameda. The complaint alleges that, during the time he served as an associate agent, we misclassified him as an independent contractor instead of an employee. The plaintiff also asserts representative claims under PAGA. The plaintiff is seeking unspecified amounts of unpaid overtime wages, regular wages, meal and rest period compensation, penalties, injunctive, and other equitable relief, and plaintiff's attorneys' fees and costs. On September 27, 2021, the court granted our motion to stay the plaintiff’s action pending resolution of the PAGA claims brought against us by Devin Cook described above. Settled Employment Claim —On April 6, 2021, two of our former employees and one of our current employees (together, the "claimants") submitted notices to the California Labor & Workforce Development Agency (the "LWDA") to notify the LWDA that they intend to seek penalties against us under PAGA for our alleged violations of provisions of the California Labor Code (the "CLC"). With respect to some or all of the claimants, these violations relate to alleged non-payment of owed wages, improper wage deductions, not providing wage statements, retaliation, failure to keep payroll records, failure to pay a minimum wage, failure to provide a written agreement regarding commission payments, and failure to reimburse business expenses. Certain of these violations are also asserted on behalf of other allegedly aggrieved employees. The claimants had also previously submitted complaints against us and two of our former employees to the California Department of Fair Employment and Housing alleging violations of provisions of the California Fair Employment and Housing Act (the "CFEHA") related to harassment, discrimination, and retaliation. On September 29, 2021, the claimants agreed to settle their claims regarding our alleged violations of the CLC and the CFEHA in exchange for a monetary payment, which was not material to our consolidated financial statements taken as a whole. We previously accrued a legal settlement expense for our initial settlement offer in the first quarter of 2021 that the claimants had rejected. We settled the claim for an amount less than the previously accrued legal expense. We also received funds from our insurance carrier for a portion of the settlement amount. The difference between our initial settlement offer and our final settlement is recorded in general and administrative on our consolidated statements of comprehensive (loss) income. Other Commitments Other commitments primarily relate to homes that are under contract to purchase through our properties business but that have not closed. As of September 30, 2021, the value of homes under contract that have not closed was $137,325.

Acquired Intangible Assets and

Acquired Intangible Assets and Goodwill	9 Months Ended
	Sep. 30, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
Acquired Intangible Assets and Goodwill	Acquired Intangible Assets and Goodwill Acquired Intangible Assets —The following table presents the gross carrying amount and accumulated amortization of intangible assets: September 30, 2021 December 31, 2020 Weighted-Average Useful Lives (Years) Gross Accumulated Amortization Net Gross Accumulated Amortization Net Trade names 10 $ 71,040 $ (4,228) $ 66,812 $ 1,040 $ (650) $ 390 Developed technology 3.3 63,480 (12,169) 51,311 2,980 (1,862) 1,118 Customer relationships 10 81,360 (4,627) 76,733 860 (538) 322 Total $ 215,880 $ (21,024) $ 194,856 $ 4,880 $ (3,050) $ 1,830 Amortization expense amounted to $8,926 and $122 for the three months ended September 30, 2021 and 2020, respectively, and $17,974 and $366 for the nine months ended September 30, 2021 and 2020, respectively. The following table presents our estimate of remaining amortization expense for intangible assets that existed as of September 30, 2021: 2021, excluding the nine months ended September 30, 2021 $ 8,926 2022 35,705 2023 35,705 2024 20,458 2025 15,050 Thereafter 79,012 Estimated remaining amortization expense $ 194,856 Goodwill —The following table presents the carrying amount of goodwill: Balance as of December 31, 2020 $ 9,186 Goodwill resulting from acquisition 398,042 Balance as of September 30, 2021 $ 407,228

Accrued Liabilities

Accrued Liabilities	9 Months Ended
	Sep. 30, 2021
Payables and Accruals [Abstract]
Accrued Liabilities	Accrued Liabilities The components of accrued liabilities were as follows: September 30, 2021 December 31, 2020 Accrued compensation and benefits $ 68,230 $ 49,238 Miscellaneous accrued liabilities 20,015 9,722 Payroll tax liability deferred by the CARES Act 7,841 6,812 Customer contract liabilities 5,941 3,688 Total accrued liabilities $ 102,027 $ 69,460

Other Payables

Other Payables	9 Months Ended
	Sep. 30, 2021
Payables and Accruals [Abstract]
Other Payables	Other Payables Other payables consists primarily of customer deposits for cash held in escrow on behalf of real estate buyers using our title and settlement services. Since we do not have rights to the cash, the customer deposits are recorded as a liability with a corresponding asset in the same amount recorded within restricted cash. The components of other payables were as follows: September 30, 2021 December 31, 2020 Customer deposits $ 14,344 $ 11,183 Miscellaneous payables 2,422 2,001 Total other payables $ 16,766 $ 13,184

Mezzanine Equity

Mezzanine Equity	9 Months Ended
	Sep. 30, 2021
Temporary Equity Disclosure [Abstract]
Mezzanine Equity	Mezzanine Equity On April 1, 2020, we issued 4,484,305 shares of our common stock, at a price of $15.61 per share, and 40,000 shares of our preferred stock, at a price of $1,000 per share, for aggregate gross proceeds of $110,000. We designated this preferred stock as Series A Convertible Preferred Stock (our "convertible preferred stock"). Our convertible preferred stock is classified as mezzanine equity in our consolidated financial statements as the substantive conversion features at the option of the holder precludes liability classification. We have determined there are no material embedded features that require recognition as a derivative asset or liability. We allocated the gross proceeds of $110,000 to the common stock issuance and the convertible preferred stock issuance based on the standalone fair value of the issuances, resulting in a fair valuation of $40,000 for the preferred stock, which is also the value of the mandatory redemption amount. As of September 30, 2021, the carrying value of our convertible preferred stock, net of issuance costs, is $39,857, and holders have earned unpaid stock dividends in the amount of 30,640 shares of common stock. This stock dividend was issued on October 1, 2021. These shares are included in basic and diluted net (loss) income per share attributable to common stock in Note 14. As of September 30, 2021, no shares of the preferred stock have been converted, and the preferred stock was not redeemable, nor probable to become redeemable in the future as there is a more than remote chance the shares will be automatically converted prior to the mandatory redemption date. The number of shares of common stock reserved for future issuance resulting from dividends, conversion, or redemption with respect to the preferred stock was 2,622,177 as of the issuance date. Dividends —The holders of our convertible preferred stock are entitled to dividends. Dividends accrue daily based on a 360 day fiscal year at a rate of 5.5% per annum based on the issue price and are payable quarterly in arrears on the first business day following the end of each calendar quarter. Assuming we satisfy certain conditions, we will pay dividends in shares of common stock at a rate of the dividend payable divided by $17.95. If we do not satisfy such conditions, we will pay dividends in a cash amount equal to (i) the dividend shares otherwise issuable on the dividends multiplied by (ii) the volume-weighted average closing price of our common stock for the ten trading days preceding the date the dividends are payable. Participation Rights —Holders of our convertible preferred stock are entitled to dividends paid and distributions made to holders of our common stock to the same extent as if such preferred stockholders had converted their shares of preferred stock into common stock and held such shares on the record date for such dividends and distributions. Conversion —Holders may convert their convertible preferred stock into common stock at any time at a rate per share of preferred stock equal to the issue price divided by $19.51 (the "conversion price"). A holder that converts will also receive any dividend shares resulting from accrued dividends. Our convertible preferred stock may also be automatically converted to shares of our common stock. If the closing price of our common stock exceeds $27.32 per share (i) for each day of the 30 consecutive trading days immediately preceding April 1, 2023 or (ii) following April 1, 2023 until 30 trading days prior to November 30, 2024, for each day of any 30 consecutive trading days, then each outstanding share of preferred stock will automatically convert into a number of shares of our common stock at a rate per share of preferred stock equal to the issue price divided by the conversion price. Upon an automatic conversion, a holder will also receive any dividend shares resulting from accrued dividends. Redemption —On November 30, 2024, we will be required to redeem any outstanding shares of our convertible preferred stock, and each holder may elect to receive cash, shares of common stock, or a combination of cash and shares. If a holder elects to receive cash, we will pay, for each share of preferred stock, an amount equal to the issue price plus any accrued dividends. If a holder elects to receive shares, we will issue, for each share of preferred stock, a number of shares of common stock at a rate of the issue price divided by the conversion price plus any dividend shares resulting from accrued dividends. A holder of our convertible preferred stock has the right to require us to redeem up to all shares of preferred stock it holds following certain events outlined in the document governing the preferred stock. If a holder redeems as the result of such events, such holder may elect to receive cash or shares of common stock, as calculated in the same manner as the mandatory redemption described above. Additionally, such holder will also receive, in cash or shares of common stock as elected by the holder, an amount equal to all scheduled dividend payments on the preferred stock for all remaining dividend periods from the date the holder gives its notice of redemption. Liquidation Rights —Upon our liquidation, dissolution, or winding up, holders of our convertible preferred stock will be entitled to receive cash out of our assets prior to holders of the common stock.

Equity and Equity Compensation

Equity and Equity Compensation Plans	9 Months Ended
	Sep. 30, 2021
Share-based Payment Arrangement [Abstract]
Equity and Equity Compensation Plans	Equity and Equity Compensation Plans Common Stock —As of September 30, 2021 and December 31, 2020, our amended and restated certificate of incorporation authorized us to issue 500,000,000 shares of common stock with a par value of $0.001 per share. Preferred Stock —As of September 30, 2021 and December 31, 2020, our amended and restated certificate of incorporation authorized us to issue 10,000,000 shares of preferred stock with a par value of $0.001. Amended and Restated 2004 Equity Incentive Plan —We granted options under our 2004 Equity Incentive Plan, as amended (our "2004 Plan"), until July 26, 2017, when we terminated it in connection with our initial public offering. Accordingly, no shares are available for future issuance under our 2004 Plan. Our 2004 Plan continues to govern outstanding equity awards granted thereunder. The term of each stock option under the plan is no more than 10 years, and each stock option generally vests over a four-year period. 2017 Equity Incentive Plan —Our 2017 Equity Incentive Plan (our "2017 EIP") became effective on July 26, 2017, and provides for the issuance of incentive and nonqualified common stock options and restricted stock units to employees, directors, and consultants. The number of shares of common stock initially reserved for issuance under our 2017 EIP was 7,898,159. The number of shares reserved for issuance under our 2017 EIP will increase automatically on January 1 of each calendar year beginning on January 1, 2018, and continuing through January 1, 2028, by the number of shares equal to the lesser of 5% of the total outstanding shares of our common stock as of the immediately preceding December 31 or an amount determined by our board of directors. The term of each stock option and restricted stock unit under the plan will not exceed 10 years, and each award generally vests between two We have reserved shares of common stock for future issuance under our 2017 EIP as follows: September 30, 2021 December 31, 2020 Stock options issued and outstanding 4,374,257 5,733,738 Restricted stock units outstanding 3,452,462 4,459,743 Shares available for future equity grants 16,718,941 11,309,377 Total shares reserved for future issuance 24,545,660 21,502,858 2017 Employee Stock Purchase Plan —Our 2017 Employee Stock Purchase Plan (our "ESPP") was approved by our board of directors on July 27, 2017 and enables eligible employees to purchase shares of our common stock at a discount. Purchases will be accomplished through participation in discrete offering periods. We initially reserved 1,600,000 shares of common stock for issuance under our ESPP. The number of shares reserved for issuance under our ESPP will increase automatically on January 1 of each calendar year beginning after the first offering date and continuing through January 1, 2028, by the number of shares equal to the lesser of 1% of the total outstanding shares of our common stock as of the immediately preceding December 31 or an amount determined by our board of directors. On each purchase date, eligible employees will purchase our common stock at a price per share equal to 85% of the lesser of (i) the fair market value of our common stock on the first trading day of the offering period and (ii) the fair market value of our common stock on the purchase date. We have reserved shares of common stock for future issuance under our ESPP as follows: Nine Months Ended September 30, 2021 Year Ended December 31, 2020 Shares available for issuance at beginning of period 4,039,667 3,330,271 Shares issued during the period (135,426) (320,609) Total shares available for future issuance at end of period 3,904,241 3,009,662 Stock Options —Option activity for the nine months ended September 30, 2021 was as follows: Number of Options Weighted-Average Exercise Price Weighted-Average Remaining Contractual Life (Years) Aggregate Intrinsic Value Outstanding as of January 1, 2021 5,733,738 $ 7.23 4.39 $ 352,076 Options exercised (1,354,078) 5.10 Options forfeited (290) 10.80 Options expired (5,113) 10.80 Outstanding as of September 30, 2021 4,374,257 7.88 3.92 184,685 Options exercisable as of September 30, 2021 4,224,257 7.18 3.78 181,295 The grant date fair value of our stock options is recorded as stock-based compensation over the stock options' vesting period.Our unvested stock options consist solely of stock options subject to performance conditions ("PSOs"), with a target of 150,000 shares and a maximum 300,000 shares, held by our chief executive officer. The options have an exercise price of $27.50 per share and have the same performance and vesting conditions as the restricted stock units subject to performance conditions that we granted in 2019. We determined that vesting is probable and have accrued compensation expense for the PSOs. None of the options vested during the nine months ended September 30, 2021. As of September 30, 2021, we have $95 of total unrecognized compensation cost related to these PSOs. These costs are expected to be recognized over a weighted-average period of 3 months. Restricted Stock Units —Restricted stock unit activity for the nine months ended September 30, 2021 was as follows: Restricted Stock Units Weighted-Average Grant-Date Fair Value Outstanding as of January 1, 2021 4,459,743 $ 27.44 Granted 658,610 55.89 Vested (1) (1,072,378) 22.39 Forfeited or canceled (593,513) 26.42 Outstanding or deferred as of September 30, 2021 (1) 3,452,462 34.62 (1) Starting with the restricted stock units granted to them in June 2019, our non-employee directors have the option to defer the issuance of common stock receivable upon vesting of such restricted stock units until 60 days following the day they are no longer providing services to us or, if earlier, upon a change in control transaction. The amount reported as vested excludes restricted stock units that have vested but whose settlement into shares has been deferred. The amount reported as outstanding or deferred as of September 30, 2021 includes these restricted stock units. As no further conditions exist to prevent the issuance of the shares of common stock underlying these restricted stock units, the shares are included in basic and diluted weighted shares outstanding used to calculate net (loss) income per share attributable to common stock. The amount of shares whose issuance have been deferred is not considered material and is not reported separately from stock-based compensation in our consolidated statements of changes in mezzanine equity and stockholders’ equity. The grant date fair value of restricted stock units is recorded as stock-based compensation over the vesting period. As of September 30, 2021, there was $99,783 of total unrecognized compensation cost related to restricted stock units, which is expected to be recognized over a weighted-average period of 2.29 years. As of September 30, 2021, there were 331,759 restricted stock units subject to performance and market conditions ("PSUs") at 100% of the target level. Depending on our achievement of the performance and market conditions, the actual number of shares of common stock issuable upon vesting of PSUs will range from 0% to 200% of the target amount. For each PSU recipient, the awards will vest only if the recipient is continuing to provide service to us upon our board of directors, or its compensation committee, certifying that we have achieved the PSU's related performance or market conditions. Stock-based compensation expense for PSUs with performance conditions is recognized when it is probable that the performance conditions will be achieved. For PSUs with market conditions, the market condition is reflected in the grant-date fair value of the award and the expense is recognized over the life of the award. Stock-compensation expense associated with the PSUs is as follows: Nine Months Ended September 30, 2021 2020 Expense associated with the current period $ 4,465 $ (610) Expense due to reassessment of achievement related to prior periods — 484 Total expense $ 4,465 $ (126) Compensation Cost —The following table details, for each period indicated, our stock-based compensation, net of forfeitures, and the amount capitalized in website and software development costs, each as included in our consolidated statements of comprehensive (loss) income: Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Cost of revenue $ 3,283 $ 2,574 $ 10,019 $ 5,981 Technology and development (1) 5,455 4,964 16,987 11,736 Marketing 537 403 1,615 1,130 General and administrative 3,835 3,407 10,817 6,917 Total stock-based compensation $ 13,110 $ 11,348 $ 39,438 $ 25,764

Net (Loss) Income per Share Att

Net (Loss) Income per Share Attributable to Common Stock	9 Months Ended
	Sep. 30, 2021
Earnings Per Share [Abstract]
Net (Loss) Income per Share Attributable to Common Stock	Net (Loss) Income per Share Attributable to Common Stock Net (loss) income per share attributable to common stock is computed by dividing the net (loss) income attributable to common stock by the weighted-average number of common shares outstanding. We have outstanding stock options, restricted stock units, options to purchase shares under our ESPP, convertible preferred stock, and convertible senior notes, which are considered in the calculation of diluted net (loss) income per share whenever doing so would be dilutive. We calculate basic and diluted net (loss) income per share attributable to common stock in conformity with the two-class method required for companies with participating securities. We consider our convertible preferred stock to be participating securities. Under the two-class method, net loss attributable to common stock is not allocated to the preferred stock as its holders do not have a contractual obligation to share in losses, as discussed in Note 12. The calculation of basic and diluted net (loss) income per share attributable to common stock was as follows: Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Numerator: Net (loss) income $ (18,949) $ 34,166 $ (82,611) $ (32,562) Dividends on convertible preferred stock (1,662) (1,530) (5,875) (2,814) Undistributed earnings attributable to participating securities — (653) — — Net (loss) income attributable to common stock—basic and diluted $ (20,611) $ 31,983 $ (88,486) $ (35,376) Denominator: Weighted-average shares—basic (1) 105,144,872 99,840,144 104,327,614 97,365,122 Dilutive shares from stock plans — 7,767,567 $ — — Weighted-average shares—diluted (1) 105,144,872 107,607,711 104,327,614 97,365,122 Net (loss) income per share: Net (loss) income per share attributable to common stock—basic $ (0.20) $ 0.32 $ (0.85) $ (0.36) Net (loss) income per share attributable to common stock—diluted $ (0.20) $ 0.30 $ (0.85) $ (0.36) (1) Basic and diluted weighted-average shares outstanding include (i) common stock earned but not yet issued related to share-based dividends on our convertible preferred stock, and (ii) restricted stock units that have vested but whose settlement into common stock were deferred at the option of certain non-employee directors. The following outstanding shares of common stock equivalents were excluded from the computation of the diluted net (loss) income per share for the periods presented because their effect would have been anti-dilutive: Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 2023 notes as if converted 769,623 4,705,398 769,623 4,705,398 2025 notes as if converted 9,119,960 — 9,119,960 — 2027 notes as if converted 6,147,900 — 6,147,900 — Convertible preferred stock as if converted 2,040,000 2,040,000 2,040,000 2,040,000 Stock options outstanding (1) 4,374,257 — 4,374,257 5,924,213 Restricted stock units outstanding (1)(2) 3,424,733 — 3,424,733 3,932,539 Employee stock purchase plan 153,208 — 153,208 130,589 Total 26,029,681 6,745,398 26,029,681 16,732,739 (1) Excludes 331,759 incremental PSUs and 150,000 incremental PSOs that could vest, assuming applicable performance criteria and market conditions are achieved at 200% of target, which is the maximum achievement level. See Note 13 for additional information regarding PSUs and PSOs.

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2021
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes During the nine months ended September 30, 2021, we recorded an income tax benefit of $5,363, resulting in an effective tax rate of 6.10%, which is primarily a result of a deferred tax liability created through our April 2, 2021 acquisition of RentPath and can be used to realize certain deferred tax assets against which we had previously recorded a full valuation allowance. Our September 30, 2020 effective tax rate of 0% is a result of our previously recorded full valuation allowance against our deferred tax assets. In determining the realizability of the net U.S. federal and state deferred tax assets, we consider numerous factors including historical profitability, estimated future taxable income, prudent and feasible tax planning strategies, and the industry in which we operate. Management reassesses the realization of the deferred tax assets each reporting period, which resulted in a valuation allowance against the full amount of our U.S. deferred tax assets for the nine months ended September 30, 2021 and 2020. To the extent that the financial results of our U.S. operations improve in the future and the deferred tax assets become realizable, we will reduce the valuation allowance through earnings. Under Section 382 of the Internal Revenue Code of 1986, as amended, substantial changes in our ownership may limit the amount of net operating loss ("NOL") carryforwards that could be utilized annually in the future to offset taxable income. Any such annual limitation may significantly reduce the utilization of the NOLs before they expire. A Section 382 limitation study performed as of March 31, 2017 determined that Redfin experienced an ownership change in 2006 and $1,538 of the 2006 NOL is unavailable. Furthermore, in connection with our acquisition of RentPath, RentPath experienced an ownership change that triggered Sections 382. As of September 30, 2021, RentPath completed a Section 382 limitation study and based on this analysis, we do not expect a reduction in our ability to fully utilize RentPath's pre-ownership change NOLs. As of December 31, 2020, we had accumulated approximately $227,751 of federal net operating losses, $12,576 (tax effected) of state net operating losses, and $2,050 of foreign net operating losses. Federal net operating losses are available to offset federal taxable income and begin to expire in 2025. Federal net operating loss carryforwards of $142,420 generated after 2017 available to offset future U.S. federal taxable income over an indefinite period. As of April 2, 2021, RentPath had accumulated approximately $252,792 of federal net operating losses and $142,632 of deductible but limited federal business interest expense carryforwards. Federal net operating losses are available to offset federal taxable income and begin to expire in 2021. Federal net operating loss carryforwards of $42,911 generated after 2017 are available to offset future U.S. federal taxable income over an indefinite period. Deductible but limited federal business interest expense carryforwards are available to offset future U.S. federal taxable income over an indefinite period.

Debt

Debt	9 Months Ended
	Sep. 30, 2021
Debt Disclosure [Abstract]
Debt	Debt Warehouse Credit Facilities —To provide capital for the mortgage loans that it originates, Redfin Mortgage, our wholly owned mortgage origination subsidiary, utilizes warehouse credit facilities that are classified as current liabilities in our consolidated balance sheets. Borrowings under each warehouse credit facility are secured by the related mortgage loan and rights and income associated with the loan. The following table summarizes borrowings under these facilities as of the periods presented: September 30, 2021 December 31, 2020 Lender Borrowing Capacity Outstanding Borrowings Weighted-Average Interest Rate on Outstanding Borrowings Borrowing Capacity Outstanding Borrowings Weighted-Average Interest Rate on Outstanding Borrowings Western Alliance Bank $ 50,000 $ 16,369 3.25 % $ 50,000 $ 18,277 3.25 % Texas Capital Bank, N.A. 40,000 15,674 2.98 % 40,000 12,903 3.35 % Flagstar Bank, FSB 15,000 7,782 3.00 % 15,000 7,849 3.00 % Total $ 105,000 $ 39,825 — $ 105,000 $ 39,029 — Borrowings under the facility with Western Alliance Bank ("Western Alliance") mature on October 12, 2021 and generally bear interest at a rate equal to the greater of (i) one-month LIBOR plus 2.00% or (ii) 3.25%. Redfin Corporation has agreed to make capital contributions in an amount as necessary for Redfin Mortgage to satisfy its adjusted tangible net worth financial covenant under the agreement, but it was not obligated to make any such capital contributions as of September 30, 2021. See Note 17 for developments subsequent to September 30, 2021 with respect to this facility. Borrowings under the facility with Texas Capital Bank, N.A. ("Texas Capital") mature on September 14, 2022 and generally bear interest at a rate equal to the greater of (i) the rate of interest accruing on the outstanding principal balance of the loan minus 0.25% or (ii) 2.95%. Redfin Corporation has guaranteed Redfin Mortgage’s obligations under the agreement. Borrowings under the facility with Flagstar Bank, FSB ("Flagstar") generally bear interest at a rate equal to the greater of (i) one-month LIBOR plus 2.00% or (ii) 3.00%. This facility does not have a stated maturity date, but Flagstar may terminate the facility upon 30 days prior notice. Redfin Mortgage would be required to pay all amounts owed to Flagstar upon the facility's termination. See Note 17 for developments subsequent to September 30, 2021 with respect to this facility. Secured Revolving Credit Facility —To provide capital for the homes that it purchases, RedfinNow has, through a special purpose entity called RedfinNow Borrower, entered into a secured revolving credit facility with Goldman Sachs Bank, N.A. ("Goldman Sachs"). Borrowings under the facility are secured by RedfinNow Borrower's assets, including the financed homes, as well as the equity interests in RedfinNow Borrower. The following table summarizes borrowings under this facility as of the periods presented: September 30, 2021 December 31, 2020 Lender Borrowing Capacity Outstanding Borrowings Weighted-Average Interest Rate on Outstanding Borrowings Borrowing Capacity Outstanding Borrowings Weighted-Average Interest Rate on Outstanding Borrowings Goldman Sachs Bank USA $ 200,000 $ 199,627 3.30 % $ 100,000 $ 23,949 4.40 % The facility matures on July 12, 2022, but we may extend the maturity date for an additional six months to repay outstanding borrowings. Goldman Sachs may, at its sole option, finance a portion of RedfinNow Borrower's acquisition costs of qualified homes that have been purchased. The portion financed is based, in part, on how long the qualifying home has been owned by a Redfin entity. Each new borrowing under the facility on and after January 12, 2021 generally bears interest at a rate of one-month LIBOR (subject to a floor of 0.30%) plus 3.00%. Outstanding borrowings originated before January 12, 2021 generally bear interest at a rate of one-month LIBOR (subject to a floor of 0.50%) plus an additional rate agreed upon between RedfinNow Borrower and Goldman Sachs. RedfinNow Borrower must repay all borrowings and accrued interest upon the termination of the facility, and it has the option to repay the borrowings, and the related interest, with respect to a specific financed home upon the sale of such home. In certain situations involving a financed home remaining unsold after a certain time period or becoming ineligible for financing under the facility, RedfinNow Borrower may be obligated to repay all or a portion of the borrowings, and related interest, with respect to such home prior to the sale of such home. In instances involving "bad acts," Redfin Corporation has guaranteed repayment of amounts owed under the facility, in some situations, and indemnification of certain expenses incurred, in other situations. As of September 30, 2021, RedfinNow Borrower had $511,569 of total assets, of which $415,610 related to inventory and $25,446 in cash and cash equivalents. As of December 31, 2020, RedfinNow Borrower had $65,191 of total assets, of which $47,620 related to inventory and $11,818 in cash and equivalents. For the three months ended September 30, 2021 and 2020, we amortized $81 and $155 of debt issuance costs, respectively, and recognized $1,375 and $101 of interest expense, respectively. For the nine months ended September 30, 2021 and 2020, we amortized $217 and $464 of debt issuance costs, respectively, and recognized $2,328 and $432 of interest expense, respectively. Convertible Senior Notes —We have issued convertible senior notes with the following characteristics: Issuance Maturity Date Stated Cash Interest Rate Effective Interest Rate First Interest Payment Date Semi-Annual Interest Payment Dates Conversion Rate 2023 notes July 15, 2023 1.75 % 2.45 % January 15, 2019 January 15; July 15 32.7332 2025 notes October 15, 2025 — % 0.42 % — — 13.7920 2027 notes April 1, 2027 0.50 % 0.90 % October 1, 2021 April 1; October 1 10.6920 We issued our 2023 notes on July 23, 2018, with an aggregate principal amount of $143,750. Subsequent to the issuance date, we repurchased or settled conversions of an aggregate of $120,238 of our 2023 notes. On July 20, 2021, our 2023 notes became redeemable by us, but we did not exercise our redemption right during the three months ended September 30, 2021. We issued our 2025 notes on October 20, 2020, with an aggregate principal amount of $661,250. We issued our 2027 notes on March 25, 2021 and April 5, 2021, with an aggregate principal amount of $575,000. Our proceeds from the issuance, after deducting the initial purchasers' discount and offering expenses payable by us, were $561,529. The components of our convertible senior notes were as follows: September 30, 2021 Issuance Aggregate Principal Amount Unamortized Debt Discount Unamortized Debt Issuance Costs Net Carrying Amount 2023 notes $ 23,512 $ — $ 269 $ 23,243 2025 notes 661,250 — 11,157 650,093 2027 notes 575,000 — 12,326 562,674 December 31, 2020 Issuance Aggregate Principal Amount Unamortized Debt Discount Unamortized Debt Issuance Costs Net Carrying Amount 2023 notes $ 25,626 $ 2,776 $ 368 $ 22,482 2025 notes 661,250 163,077 9,905 488,268 Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 2023 notes Contractual interest expense $ 103 $ 629 $ 311 $ 1,887 Amortization of debt discount — 1,422 — 4,217 Amortization of debt issuance costs 41 189 151 562 Total interest expense $ 144 $ 2,240 $ 462 $ 6,666 2025 notes Contractual interest expense — — — — Amortization of debt discount — — — — Amortization of debt issuance costs 690 — 2,070 — Total interest expense $ 690 $ — $ 2,070 $ — 2027 notes Contractual interest expense 719 — 1,468 — Amortization of debt discount — — — — Amortization of debt issuance costs 560 — 1,145 — Total interest expense $ 1,279 $ — $ 2,613 $ — Total Contractual interest expense 822 629 1,779 1,887 Amortization of debt discount — 1,422 — 4,217 Amortization of debt issuance costs 1,291 189 3,366 562 Total interest expense $ 2,113 $ 2,240 $ 5,145 $ 6,666 Conversion of Our Convertible Senior Notes Prior to the free conversion date, a holder of each tranche of our convertible senior notes may convert its notes in multiples of $1,000 principal amount only if one or more of the conditions described below is satisfied. On or after the free conversion date, a holder may convert its notes in such multiples without any conditions. The free conversion date is April 15, 2023 for our 2023 notes, July 15, 2025 for our 2025 notes, and January 1, 2027 for our 2027 notes. The conditions are: • during any calendar quarter (and only during such calendar quarter), if the last reported sale price of our common stock for at least 20 trading days (whether or not consecutive) during a period of 30 consecutive trading days ending on, and including, the last trading day of the immediately preceding calendar quarter is greater than or equal to 130% of the applicable conversion price on each applicable trading day; • during the five business day period after any five consecutive trading day period in which the trading price per $1,000 principal amount of the applicable notes for each trading day of the measurement period was less than 98% of the product of the last reported sale price of our common stock and the applicable conversion rate on each such trading day • if we call any or all of the applicable notes for redemption, at any time prior to the close of business on the scheduled trading day prior to the redemption date; or • upon the occurrence of specified corporate events. With respect to our 2023 notes, the first condition described above was satisfied during the quarter ended September 30, 2021. As a result, our 2023 notes will be convertible at a holder's option during the quarter ending December 31, 2021, and have been classified as current liabilities on our consolidated balance sheet as of September 30, 2021. During the three months ended September 30, 2021, we settled conversion requests with respect to our 2023 notes with an aggregate principal amount of $226 using a combination of $234 cash and 3,164 shares. We intend to settle any future conversions of our convertible senior notes by paying or delivering, as the case may be, cash, shares of our common stock, or a combination of cash and shares of our common stock, at our election. We apply the if-converted method to calculate diluted earnings per share when applicable. Under the if-converted method, the denominator of the diluted earnings per share calculation is adjusted to reflect the full number of common shares issuable upon conversion, while the numerator is adjusted to add back interest expense for the period. Classification of Our Convertible Senior Notes Historically, we had separated our 2023 notes and our 2025 notes into liability and equity components. With our adoption of ASU 2020-06 on January 1, 2021, using the modified retrospective approach, this accounting treatment is no longer applicable. All of our convertible senior notes are now accounted for wholly as liabilities. See Note 1 for adoption information related to the new standard. The difference between the principal amount of the notes and the net carrying amount represents the unamortized debt discount, which we record as a deduction from the debt liability in our consolidated balance sheets. This discount is amortized to interest expense using the effective interest method over the term of the notes. See Note 4 for fair value information related to our convertible senior notes.

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2021
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events On October 6, 2021, we extended the maturity date of our warehouse credit facility with Western Alliance to November 12, 2021. On November 1, 2021, we increased the borrowing capacity under our warehouse credit facility with Flagstar to $25,000.

Summary of Accounting Policies

Summary of Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation —The consolidated financial statements and accompanying notes have been prepared in accordance with generally accepted accounting principles in the United States of America (“GAAP”). The financial information as of December 31, 2020 that is included in this quarterly report is derived from the audited consolidated financial statements and notes for the year ended December 31, 2020 included in Item 8 in our annual report for the year ended December 31, 2020. Such financial information should be read in conjunction with the notes and management’s discussion and analysis of the consolidated financial statements included in our annual report. The unaudited consolidated interim financial statements, in the opinion of management, reflect all adjustments, consisting only of normal recurring adjustments, necessary to present fairly our financial position as of September 30, 2021, our statements of comprehensive (loss) income, and statements of changes in mezzanine equity and stockholders’ equity for the three and nine months ended September 30, 2021 and 2020, as well as our statements of cash flows for the nine months ended September 30, 2021 and 2020. The results for the three and nine months ended September 30, 2021 are not necessarily indicative of the results to be expected for the year ending December 31, 2021 or for any interim period or for any other future year. Certain amounts presented in the prior period consolidated statements of cash flows have been reclassified to conform to the current period financial statement presentation. The change in classification does not affect previously reported cash flows from operating activities, investing activities, or financing activities in the consolidated statements of cash flows.
Principles of Consolidation	Principles of Consolidation —The unaudited consolidated interim financial statements include the accounts of Redfin Corporation and its wholly owned subsidiaries, including those entities in which we have a variable interest and of which we are the primary beneficiary. Intercompany transactions and balances have been eliminated.
Use of Estimates	Use of Estimates —The preparation of consolidated financial statements, in conformity with GAAP, requires our management to make estimates and assumptions that affect the reported amounts of assets and liabilities and results of operations during the respective periods. Our estimates include, but are not limited to, the valuation of deferred income taxes, stock-based compensation, net realizable value of inventory, capitalization of website and software development costs, the incremental borrowing rate for the determination of the present value of lease payments, recoverability of intangible assets with finite lives, fair value of our mortgage loans held for sale, fair value of interest rate lock commitments, and forward sales commitments, fair value of reporting units for purposes of evaluating goodwill for impairment, current expected credit losses on certain financial assets, the fair value of the convertible feature related to our convertible senior notes, and the fair value of assets acquired and liabilities assumed in connection with our acquisition of RentPath. The amounts ultimately realized from the affected assets or ultimately recognized as liabilities will depend on, among other factors, general business conditions and could differ materially in the near term from the carrying amounts reflected in the consolidated financial statements.
Debt, Policy	Convertible Senior Notes —In accounting for the issuance of our convertible senior notes, we treat the instrument wholly as a liability, in accordance with the adoption of ASU 2020-06, Debt—Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging—Contracts in Entity's Own Equity (Subtopic 815-40): Accounting for Convertible Instruments and Contracts in an Entity's Own Equity ("ASU 2020-06"). Issuance costs are being amortized to expense over the respective term of the convertible senior notes.
Revenue from Contract with Customer	Rentals Revenue —Due to our acquisition of RentPath, we now record rentals revenue which is primarily composed of subscription-based product offerings for internet listing services, as well as lead management and digital marketing solutions. Rentals revenue is recorded as a component of service revenue in our consolidated statements of comprehensive (loss) income. Revenue is recognized upon transfer of control of promised service to customers over time in an amount that reflects the consideration we expect to receive in exchange for those services. Revenues from subscription-based services are recognized on a straight-line basis over the term of the contract, which generally have a term of less than one year. Revenue is presented net of sales allowances, which are not material. The transaction price for a contract is generally determined by the stated price in the contract, excluding any related sales taxes. We enter into contracts that can include various combinations of subscription services, which are capable of being distinct and accounted for as separate performance obligations. We allocate the transaction price to each performance obligation in the contract on a relative stand-alone selling price basis. Generally, the combinations of subscription services are fulfilled concurrently and are co-terminus. Our rentals contracts do not contain any refund provisions other than in the event of our non-performance or breach.
Recently Adopted and Issued Accounting Pronouncements	Recently Adopted Accounting Pronouncements —In August 2020, the Financial Accounting Standards Board (the "FASB") issued authoritative guidance under ASU 2020-06. This guidance removes the liability and equity separation models for convertible instruments with a cash conversion feature or beneficial conversion feature. As a result, companies will more likely account for a convertible debt instrument wholly as debt, and for convertible preferred stock wholly as preferred stock (i.e., as a single unit of account). In addition, the guidance simplifies the settlement assessment that issuers perform to determine whether a contract in their own equity qualifies for equity classification. Finally, the guidance requires entities to use the if-converted method to calculate earnings per share for all convertible instruments. We early adopted ASU 2020-06 as of January 1, 2021 using the modified retrospective approach. The cumulative effect of initially applying the new standard was recognized as an adjustment to accumulated deficit. Upon the adoption of the new standard we recognized the following adjustments: Ending Balance as of December 31, 2020 ASU 2020-06 Adjustments Beginning Balance as of January 1, 2021 Convertible senior notes, net $ 22,482 $ 2,723 $ 25,205 Convertible senior notes, net, noncurrent 488,268 159,755 648,023 Additional paid-in capital 860,556 (170,240) 690,316 Accumulated deficit (270,313) 7,762 (262,551) The $7,762 adjustment to accumulated deficit represents a reduction to non-cash interest expense related to the accretion of the debt discount under the historical separation model.

Summary of Accounting Policie_2

Summary of Accounting Policies (Tables)	9 Months Ended
	Sep. 30, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Accounting Standards Update and Change in Accounting Principle	Upon the adoption of the new standard we recognized the following adjustments: Ending Balance as of December 31, 2020 ASU 2020-06 Adjustments Beginning Balance as of January 1, 2021 Convertible senior notes, net $ 22,482 $ 2,723 $ 25,205 Convertible senior notes, net, noncurrent 488,268 159,755 648,023 Additional paid-in capital 860,556 (170,240) 690,316 Accumulated deficit (270,313) 7,762 (262,551)

Business Combinations (Tables)

Business Combinations (Tables)	9 Months Ended
	Sep. 30, 2021
Business Combination and Asset Acquisition [Abstract]
Schedule of Recognized Identified Assets Acquired and Liabilities Assumed	The following table summarizes the fair value of assets acquired and liabilities assumed as a result of the Acquisition. As of September 30, 2021, the amount allocated to the opening balance of deferred tax liabilities assumed in the Acquisition is provisional and subject to revision as more detailed analyses are completed and additional information about the amount of this balance becomes available: Cash and cash equivalents (1) $ 334 Accounts receivable 7,726 Prepaid expenses 5,483 Other current assets 416 Property and equipment, net 3,103 Operating lease right-of-use assets 12,330 Intangible assets 211,000 Goodwill 398,042 Total assets 638,434 Accounts payable (1,355) Accrued liabilities (1) (9,412) Lease liabilities (1,264) Lease liabilities and deposits, noncurrent (11,066) Payroll tax liabilities, noncurrent (1,030) Deferred tax liabilities (6,307) Total liabilities (30,434) Total purchase consideration $ 608,000 (1) On April 2, 2021, $334 of cash and cash equivalents owed to a wind-down company remained in RentPath's primary operating account due to the timing of bank transfers and wires. The cash and cash equivalents were recorded at fair value along with an offsetting due-to liability on April 2, 2021.
Schedule of Finite-Lived Intangible Assets Acquired as Part of Business Combination	The following table provides the fair values of the RentPath intangible assets, along with their estimated useful lives: Estimated Fair Value Estimated Useful Life Trade names $ 70,000 10 Developed technology 60,500 3 Customer relationships 80,500 10 Total 211,000
Business Acquisition, Pro Forma Information	The pro forma financial information presented below includes adjustments for bankruptcy costs, depreciation and amortization, provision for income taxes, transaction costs, and interest expense related to debt that would not have been incurred if we had consummated the Acquisition on January 1, 2020: Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Revenue $ 540,074 $ 284,275 $ 1,322,632 $ 790,662 Net (loss) income (18,792) 23,099 (94,335) (60,918)

Segment Reporting and Revenue (

Segment Reporting and Revenue (Tables)	9 Months Ended
	Sep. 30, 2021
Segment Reporting [Abstract]
Reconciliation of Operating Profit (Loss) from Segments to Consolidated	Information on each of the reportable and other segments and reconciliation to consolidated net (loss) income is as follows: Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Revenue Real estate services (brokerage) $ 243,575 $ 194,375 $ 637,532 $ 425,269 Real estate services (partner) 14,220 15,478 41,070 28,269 Properties 238,417 19,005 503,588 170,287 Rentals 40,406 — 82,954 — Other 8,206 8,503 26,084 19,999 Intercompany eliminations (4,750) (445) (11,520) (2,248) Total $ 540,074 $ 236,916 $ 1,279,708 $ 641,576 Cost of revenue Real estate services 161,449 117,944 453,790 300,305 Properties 238,397 20,460 496,948 173,107 Rentals 7,395 — 14,965 — Other 10,281 5,885 29,729 18,422 Intercompany eliminations (4,750) (445) (11,520) (2,248) Total $ 412,772 $ 143,844 $ 983,912 $ 489,586 Gross profit Real estate services 96,346 91,909 224,812 153,233 Properties 20 (1,455) 6,640 (2,820) Rentals 33,011 — 67,989 — Other (2,075) 2,618 (3,645) 1,577 Total $ 127,302 $ 93,072 $ 295,796 $ 151,990 Real estate services, properties, and other operating expenses 96,910 56,063 281,569 176,837 Rentals operating expenses 50,286 — 98,950 — Interest income 178 319 472 1,859 Interest expense (3,672) (2,522) (7,822) (7,631) Income tax benefit 311 — 5,363 — Other income (expense), net 4,128 (640) 4,099 (1,943) Net (loss) income $ (18,949) $ 34,166 $ (82,611) $ (32,562)

Financial Instruments (Tables)

Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2021
Fair Value Disclosures [Abstract]
Schedule of Notional Amounts of Outstanding Derivative Positions	Notional Amounts September 30, 2021 December 31, 2020 Forward sales commitments $ 96,397 $ 130,109 IRLCs 94,301 88,923
Derivative Instruments, Gain (Loss)	The locations and amounts of gains (losses) recognized in income related to our derivatives are as follows: Three Months Ended September 30, Nine Months Ended September 30, Instrument Classification 2021 2020 2021 2020 Forward sales commitments Service revenue $ 859 $ 553 $ 938 $ 442 IRLCs Service revenue (888) (233) (687) 1,131
Schedule of Assets, Liabilities, and Equity Measured at Fair Value on a Recurring Basis	A summary of assets and liabilities related to our financial instruments, measured at fair value on a recurring basis and as reflected in our consolidated balance sheets, is set forth below: Balance at September 30, 2021 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets Cash equivalents Money market funds $ 501,432 $ 501,432 $ — $ — Total cash equivalents 501,432 501,432 — — Short-term investments U.S. treasury securities 11,981 11,981 — — Agency bonds 11,912 11,912 — — Equity securities 4,685 4,685 — — Loans held for sale 42,762 — 42,762 — Other current assets Forward sales commitments 552 — 552 — IRLCs 1,146 — — 1,146 Total other current assets 1,698 — 552 1,146 Long-term investments U.S. treasury securities 53,488 53,488 — — Total assets $ 627,958 $ 583,498 $ 43,314 $ 1,146 Liabilities Accrued liabilities Forward sales commitments $ 87 $ — $ 87 $ — IRLCs 62 — — 62 Total liabilities $ 149 $ — $ 87 $ 62 Balance at December 31, 2020 Quoted Prices in Active Markets for Identical Assets Significant Significant Assets Cash equivalents Money market funds $ 886,261 $ 886,261 $ — $ — U.S. treasury securities 6,100 6,100 — — Total cash equivalents 892,361 892,361 — — Short-term investments U.S. treasury securities 131,561 131,561 — — Loans held for sale 42,539 — 42,539 — Other current assets Forward sales commitments 34 — 34 — IRLCs 1,781 — — 1,781 Total other current assets 1,815 — 34 1,781 Long-term investments Agency bonds 11,922 11,922 — — Total assets $ 1,080,198 $ 1,035,844 $ 42,573 $ 1,781 Liabilities Accrued liabilities Forward sales commitments $ 507 $ — $ 507 $ — IRLCs 10 — — 10 Total liabilities $ 517 $ — $ 507 $ 10
Summary of Fair Value Measurement Inputs and Valuation Techniques	The pull-through rate used to determine the fair value of IRLCs was as follows: Key Inputs Valuation Technique September 30, 2021 December 31, 2020 Weighted-average pull-through rate Market pricing 71.7% 72.3%
Summary of Changes Fair Value Of Interest Rate Derivatives	The following is a summary of changes in the fair value of IRLCs for the nine months ended September 30, 2021: Balance, net—January 1, 2021 $ 1,771 Issuances of IRLCs 14,523 Settlements of IRLCs (14,956) Net loss recognized in earnings (254) Balance, net—September 30, 2021 $ 1,084 Changes in fair value recognized during the period relating to assets still held at September 30, 2021 $ (687)
Schedule of Long-term Debt	The following table presents the carrying amounts and estimated fair values of our convertible senior notes that are not recorded at fair value on our consolidated balance sheets: September 30, 2021 December 31, 2020 Issuance Net Carrying Amount Estimated Fair Value Net Carrying Amount Estimated Fair Value 2023 notes $ 23,243 $ 38,980 $ 22,482 $ 59,894 2025 notes 650,093 660,556 488,268 802,083 2027 notes 562,674 516,856 — — September 30, 2021 December 31, 2020 Lender Borrowing Capacity Outstanding Borrowings Weighted-Average Interest Rate on Outstanding Borrowings Borrowing Capacity Outstanding Borrowings Weighted-Average Interest Rate on Outstanding Borrowings Western Alliance Bank $ 50,000 $ 16,369 3.25 % $ 50,000 $ 18,277 3.25 % Texas Capital Bank, N.A. 40,000 15,674 2.98 % 40,000 12,903 3.35 % Flagstar Bank, FSB 15,000 7,782 3.00 % 15,000 7,849 3.00 % Total $ 105,000 $ 39,825 — $ 105,000 $ 39,029 — September 30, 2021 December 31, 2020 Lender Borrowing Capacity Outstanding Borrowings Weighted-Average Interest Rate on Outstanding Borrowings Borrowing Capacity Outstanding Borrowings Weighted-Average Interest Rate on Outstanding Borrowings Goldman Sachs Bank USA $ 200,000 $ 199,627 3.30 % $ 100,000 $ 23,949 4.40 %
Investments in Debt and Marketable Equity Securities (and Certain Trading Assets)	The cost or amortized cost, gross unrealized gains and losses, and estimated fair market value of our cash, money market funds, restricted cash, available-for-sale investments, and equity securities were as follows: September 30, 2021 Cost or Amortized Cost Unrealized Gains Unrealized Losses Estimated Fair Value Cash, Cash Equivalents, Restricted Cash Short-term Investments Long-term Investments Cash $ 61,282 $ — $ — $ 61,282 $ 61,282 $ — $ — Money markets funds 501,432 — — 501,432 501,432 — — Restricted cash 74,532 — — 74,532 74,532 — — U.S. treasury securities 65,461 16 (8) 65,469 — 11,981 53,488 Agency bonds 11,900 12 — 11,912 — 11,912 — Equity securities 500 4,185 — 4,685 — 4,685 — Total $ 715,107 $ 4,213 $ (8) $ 719,312 $ 637,246 $ 28,578 $ 53,488 December 31, 2020 Cost or Amortized Cost Unrealized Gains Unrealized Losses Estimated Fair Value Cash, Cash Equivalents, Restricted Cash Short-term Investments Long-term Investments Cash $ 32,915 $ — $ — $ 32,915 $ 32,915 $ — $ — Money markets funds 886,261 — — 886,261 886,261 — — Restricted cash 20,544 — — 20,544 20,544 — — U.S. treasury securities 137,502 159 — 137,661 6,100 131,561 — Agency bonds 11,900 22 — 11,922 — — 11,922 Total $ 1,089,122 $ 181 $ — $ 1,089,303 $ 945,820 $ 131,561 $ 11,922

Inventory (Tables)

Inventory (Tables)	9 Months Ended
	Sep. 30, 2021
Inventory Disclosure [Abstract]
Schedule of Inventory, Current	The components of inventory were as follows: September 30, 2021 December 31, 2020 Properties for sale $ 170,731 $ 17,153 Properties not available for sale 38,835 7,225 Properties under improvement 225,578 24,780 Inventory $ 435,144 $ 49,158

Property and Equipment (Tables)

Property and Equipment (Tables)	9 Months Ended
	Sep. 30, 2021
Property, Plant and Equipment [Abstract]
Property and Equipment	The components of property and equipment were as follows: Useful Lives (Years) September 30, 2021 December 31, 2020 Leasehold improvements Shorter of lease term or economic life $ 33,467 $ 29,558 Website and software development costs 2 - 3 46,014 33,278 Computer and office equipment 3 - 5 13,154 7,765 Software 3 1,871 1,858 Furniture 7 7,945 7,450 Property and equipment, gross 102,451 79,909 Accumulated depreciation and amortization (54,776) (41,614) Construction in progress 7,860 5,693 Property and equipment, net $ 55,535 $ 43,988

Leases (Tables)

Leases (Tables)	9 Months Ended
	Sep. 30, 2021
Leases [Abstract]
Lease, Cost	The components of lease expense were as follows: Three Months Ended September 30, Nine Months Ended September 30, Lease Cost Classification 2021 2020 2021 2020 Operating lease cost: Operating lease cost (1) Cost of revenue $ 2,400 $ 2,123 $ 7,105 $ 6,405 Operating lease cost (1) Operating expenses 1,727 1,087 4,440 3,274 Total operating lease cost $ 4,127 $ 3,210 $ 11,545 $ 9,679 Finance lease cost: Amortization of right-of-use assets Cost of revenue $ 139 $ 2 $ 335 $ 7 Interest on lease liabilities Cost of revenue 21 17 51 51 Total finance lease cost $ 160 $ 19 $ 386 $ 58 (1) Includes lease expense with initial terms of twelve months or less of $430 and $218 for the three months ended September 30, 2021 and 2020, respectively, and $1,156 and $712 for the nine months ended September 30, 2021 and 2020, respectively. Lease Term and Discount Rate September 30, 2021 December 31, 2020 Weighted-average remaining operating lease term (years) 5.1 5.2 Weighted-average remaining finance lease term (years) 3.3 3.5 Weighted-average discount rate for operating leases 4.4 % 4.4 % Weighted-average discount rate for finance leases 5.4 % 5.4 % Nine Months Ended September 30, Supplemental Cash Flow Information 2021 2020 Cash paid for amounts included in the measurement of lease liabilities Operating cash flows from operating leases $ 12,006 $ 10,584 Operating cash flows from finance leases 64 7 Financing cash flows from finance leases 226 38 Right of use assets obtained in exchange for lease liabilities Operating leases $ 6,544 $ 354 Finance leases 987 —
Lessee, Operating Lease, Liability, Maturity	Lease Liabilities Other Leases Total Lease Obligations Maturity of Lease Liabilities Operating Financing Operating 2021, excluding the nine months ended September 30, 2021 $ 4,397 $ 120 $ 256 $ 4,773 2022 16,852 478 467 17,797 2023 15,779 465 — 16,244 2024 14,324 379 — 14,703 2025 11,189 80 — 11,269 Thereafter 16,929 — — 16,929 Total lease payments $ 79,470 $ 1,522 $ 723 $ 81,715 Less: Interest (1) 8,316 124 Present value of lease liabilities $ 71,154 $ 1,398
Finance Lease, Liability, Fiscal Year Maturity	Lease Liabilities Other Leases Total Lease Obligations Maturity of Lease Liabilities Operating Financing Operating 2021, excluding the nine months ended September 30, 2021 $ 4,397 $ 120 $ 256 $ 4,773 2022 16,852 478 467 17,797 2023 15,779 465 — 16,244 2024 14,324 379 — 14,703 2025 11,189 80 — 11,269 Thereafter 16,929 — — 16,929 Total lease payments $ 79,470 $ 1,522 $ 723 $ 81,715 Less: Interest (1) 8,316 124 Present value of lease liabilities $ 71,154 $ 1,398

Acquired Intangible Assets an_2

Acquired Intangible Assets and Goodwill (Tables)	9 Months Ended
	Sep. 30, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Finite-Lived Intangible Assets	The following table presents the gross carrying amount and accumulated amortization of intangible assets: September 30, 2021 December 31, 2020 Weighted-Average Useful Lives (Years) Gross Accumulated Amortization Net Gross Accumulated Amortization Net Trade names 10 $ 71,040 $ (4,228) $ 66,812 $ 1,040 $ (650) $ 390 Developed technology 3.3 63,480 (12,169) 51,311 2,980 (1,862) 1,118 Customer relationships 10 81,360 (4,627) 76,733 860 (538) 322 Total $ 215,880 $ (21,024) $ 194,856 $ 4,880 $ (3,050) $ 1,830
Schedule of Finite-Lived Intangible Assets, Future Amortization Expense	The following table presents our estimate of remaining amortization expense for intangible assets that existed as of September 30, 2021: 2021, excluding the nine months ended September 30, 2021 $ 8,926 2022 35,705 2023 35,705 2024 20,458 2025 15,050 Thereafter 79,012 Estimated remaining amortization expense $ 194,856
Schedule of Goodwill	The following table presents the carrying amount of goodwill: Balance as of December 31, 2020 $ 9,186 Goodwill resulting from acquisition 398,042 Balance as of September 30, 2021 $ 407,228

Accrued Liabilities (Tables)

Accrued Liabilities (Tables)	9 Months Ended
	Sep. 30, 2021
Payables and Accruals [Abstract]
Schedule of Accrued Liabilities	The components of accrued liabilities were as follows: September 30, 2021 December 31, 2020 Accrued compensation and benefits $ 68,230 $ 49,238 Miscellaneous accrued liabilities 20,015 9,722 Payroll tax liability deferred by the CARES Act 7,841 6,812 Customer contract liabilities 5,941 3,688 Total accrued liabilities $ 102,027 $ 69,460

Other Payables (Tables)

Other Payables (Tables)	9 Months Ended
	Sep. 30, 2021
Payables and Accruals [Abstract]
Schedule of Other Payables	The components of other payables were as follows: September 30, 2021 December 31, 2020 Customer deposits $ 14,344 $ 11,183 Miscellaneous payables 2,422 2,001 Total other payables $ 16,766 $ 13,184

Equity and Equity Compensatio_2

Equity and Equity Compensation Plans (Tables)	9 Months Ended
	Sep. 30, 2021
Share-based Payment Arrangement [Abstract]
Schedule of Reserved Shares of Common Stock	We have reserved shares of common stock for future issuance under our 2017 EIP as follows: September 30, 2021 December 31, 2020 Stock options issued and outstanding 4,374,257 5,733,738 Restricted stock units outstanding 3,452,462 4,459,743 Shares available for future equity grants 16,718,941 11,309,377 Total shares reserved for future issuance 24,545,660 21,502,858 We have reserved shares of common stock for future issuance under our ESPP as follows: Nine Months Ended September 30, 2021 Year Ended December 31, 2020 Shares available for issuance at beginning of period 4,039,667 3,330,271 Shares issued during the period (135,426) (320,609) Total shares available for future issuance at end of period 3,904,241 3,009,662
Schedule of Stock Option Activity	Option activity for the nine months ended September 30, 2021 was as follows: Number of Options Weighted-Average Exercise Price Weighted-Average Remaining Contractual Life (Years) Aggregate Intrinsic Value Outstanding as of January 1, 2021 5,733,738 $ 7.23 4.39 $ 352,076 Options exercised (1,354,078) 5.10 Options forfeited (290) 10.80 Options expired (5,113) 10.80 Outstanding as of September 30, 2021 4,374,257 7.88 3.92 184,685 Options exercisable as of September 30, 2021 4,224,257 7.18 3.78 181,295
Schedule of Nonvested Restricted Stock Units Activity	Restricted stock unit activity for the nine months ended September 30, 2021 was as follows: Restricted Stock Units Weighted-Average Grant-Date Fair Value Outstanding as of January 1, 2021 4,459,743 $ 27.44 Granted 658,610 55.89 Vested (1) (1,072,378) 22.39 Forfeited or canceled (593,513) 26.42 Outstanding or deferred as of September 30, 2021 (1) 3,452,462 34.62 (1) Starting with the restricted stock units granted to them in June 2019, our non-employee directors have the option to defer the issuance of common stock receivable upon vesting of such restricted stock units until 60 days following the day they are no longer providing services to us or, if earlier, upon a change in control transaction. The amount reported as vested excludes restricted stock units that have vested but whose settlement into shares has been deferred. The amount reported as outstanding or deferred as of September 30, 2021 includes these restricted stock units. As no further conditions exist to prevent the issuance of the shares of common stock underlying these restricted stock units, the shares are included in basic and diluted weighted shares outstanding used to calculate net (loss) income per share attributable to common stock. The amount of shares whose issuance have been deferred is not considered material and is not reported separately from stock-based compensation in our consolidated statements of changes in mezzanine equity and stockholders’ equity.
Schedule of Allocation of Share-based Compensation Costs	Stock-compensation expense associated with the PSUs is as follows: Nine Months Ended September 30, 2021 2020 Expense associated with the current period $ 4,465 $ (610) Expense due to reassessment of achievement related to prior periods — 484 Total expense $ 4,465 $ (126) Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Cost of revenue $ 3,283 $ 2,574 $ 10,019 $ 5,981 Technology and development (1) 5,455 4,964 16,987 11,736 Marketing 537 403 1,615 1,130 General and administrative 3,835 3,407 10,817 6,917 Total stock-based compensation $ 13,110 $ 11,348 $ 39,438 $ 25,764

Net (Loss) Income per Share A_2

Net (Loss) Income per Share Attributable to Common Stock (Tables)	9 Months Ended
	Sep. 30, 2021
Earnings Per Share [Abstract]
Schedule of Basic and Diluted Earnings Per Share	The calculation of basic and diluted net (loss) income per share attributable to common stock was as follows: Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Numerator: Net (loss) income $ (18,949) $ 34,166 $ (82,611) $ (32,562) Dividends on convertible preferred stock (1,662) (1,530) (5,875) (2,814) Undistributed earnings attributable to participating securities — (653) — — Net (loss) income attributable to common stock—basic and diluted $ (20,611) $ 31,983 $ (88,486) $ (35,376) Denominator: Weighted-average shares—basic (1) 105,144,872 99,840,144 104,327,614 97,365,122 Dilutive shares from stock plans — 7,767,567 $ — — Weighted-average shares—diluted (1) 105,144,872 107,607,711 104,327,614 97,365,122 Net (loss) income per share: Net (loss) income per share attributable to common stock—basic $ (0.20) $ 0.32 $ (0.85) $ (0.36) Net (loss) income per share attributable to common stock—diluted $ (0.20) $ 0.30 $ (0.85) $ (0.36) (1) Basic and diluted weighted-average shares outstanding include (i) common stock earned but not yet issued related to share-based dividends on our convertible preferred stock, and (ii) restricted stock units that have vested but whose settlement into common stock were deferred at the option of certain non-employee directors.
Summary of Antidilutive Securities Excluded from Computation of Earnings Per Share	The following outstanding shares of common stock equivalents were excluded from the computation of the diluted net (loss) income per share for the periods presented because their effect would have been anti-dilutive: Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 2023 notes as if converted 769,623 4,705,398 769,623 4,705,398 2025 notes as if converted 9,119,960 — 9,119,960 — 2027 notes as if converted 6,147,900 — 6,147,900 — Convertible preferred stock as if converted 2,040,000 2,040,000 2,040,000 2,040,000 Stock options outstanding (1) 4,374,257 — 4,374,257 5,924,213 Restricted stock units outstanding (1)(2) 3,424,733 — 3,424,733 3,932,539 Employee stock purchase plan 153,208 — 153,208 130,589 Total 26,029,681 6,745,398 26,029,681 16,732,739 (1) Excludes 331,759 incremental PSUs and 150,000 incremental PSOs that could vest, assuming applicable performance criteria and market conditions are achieved at 200% of target, which is the maximum achievement level. See Note 13 for additional information regarding PSUs and PSOs.

Debt (Tables)

Debt (Tables)	9 Months Ended
	Sep. 30, 2021
Debt Disclosure [Abstract]
Schedule of Long-term Debt	The following table presents the carrying amounts and estimated fair values of our convertible senior notes that are not recorded at fair value on our consolidated balance sheets: September 30, 2021 December 31, 2020 Issuance Net Carrying Amount Estimated Fair Value Net Carrying Amount Estimated Fair Value 2023 notes $ 23,243 $ 38,980 $ 22,482 $ 59,894 2025 notes 650,093 660,556 488,268 802,083 2027 notes 562,674 516,856 — — September 30, 2021 December 31, 2020 Lender Borrowing Capacity Outstanding Borrowings Weighted-Average Interest Rate on Outstanding Borrowings Borrowing Capacity Outstanding Borrowings Weighted-Average Interest Rate on Outstanding Borrowings Western Alliance Bank $ 50,000 $ 16,369 3.25 % $ 50,000 $ 18,277 3.25 % Texas Capital Bank, N.A. 40,000 15,674 2.98 % 40,000 12,903 3.35 % Flagstar Bank, FSB 15,000 7,782 3.00 % 15,000 7,849 3.00 % Total $ 105,000 $ 39,825 — $ 105,000 $ 39,029 — September 30, 2021 December 31, 2020 Lender Borrowing Capacity Outstanding Borrowings Weighted-Average Interest Rate on Outstanding Borrowings Borrowing Capacity Outstanding Borrowings Weighted-Average Interest Rate on Outstanding Borrowings Goldman Sachs Bank USA $ 200,000 $ 199,627 3.30 % $ 100,000 $ 23,949 4.40 %
Convertible Debt	We have issued convertible senior notes with the following characteristics: Issuance Maturity Date Stated Cash Interest Rate Effective Interest Rate First Interest Payment Date Semi-Annual Interest Payment Dates Conversion Rate 2023 notes July 15, 2023 1.75 % 2.45 % January 15, 2019 January 15; July 15 32.7332 2025 notes October 15, 2025 — % 0.42 % — — 13.7920 2027 notes April 1, 2027 0.50 % 0.90 % October 1, 2021 April 1; October 1 10.6920 We issued our 2023 notes on July 23, 2018, with an aggregate principal amount of $143,750. Subsequent to the issuance date, we repurchased or settled conversions of an aggregate of $120,238 of our 2023 notes. On July 20, 2021, our 2023 notes became redeemable by us, but we did not exercise our redemption right during the three months ended September 30, 2021. We issued our 2025 notes on October 20, 2020, with an aggregate principal amount of $661,250. We issued our 2027 notes on March 25, 2021 and April 5, 2021, with an aggregate principal amount of $575,000. Our proceeds from the issuance, after deducting the initial purchasers' discount and offering expenses payable by us, were $561,529. The components of our convertible senior notes were as follows: September 30, 2021 Issuance Aggregate Principal Amount Unamortized Debt Discount Unamortized Debt Issuance Costs Net Carrying Amount 2023 notes $ 23,512 $ — $ 269 $ 23,243 2025 notes 661,250 — 11,157 650,093 2027 notes 575,000 — 12,326 562,674 December 31, 2020 Issuance Aggregate Principal Amount Unamortized Debt Discount Unamortized Debt Issuance Costs Net Carrying Amount 2023 notes $ 25,626 $ 2,776 $ 368 $ 22,482 2025 notes 661,250 163,077 9,905 488,268
Interest Income and Interest Expense Disclosure	Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 2023 notes Contractual interest expense $ 103 $ 629 $ 311 $ 1,887 Amortization of debt discount — 1,422 — 4,217 Amortization of debt issuance costs 41 189 151 562 Total interest expense $ 144 $ 2,240 $ 462 $ 6,666 2025 notes Contractual interest expense — — — — Amortization of debt discount — — — — Amortization of debt issuance costs 690 — 2,070 — Total interest expense $ 690 $ — $ 2,070 $ — 2027 notes Contractual interest expense 719 — 1,468 — Amortization of debt discount — — — — Amortization of debt issuance costs 560 — 1,145 — Total interest expense $ 1,279 $ — $ 2,613 $ — Total Contractual interest expense 822 629 1,779 1,887 Amortization of debt discount — 1,422 — 4,217 Amortization of debt issuance costs 1,291 189 3,366 562 Total interest expense $ 2,113 $ 2,240 $ 5,145 $ 6,666

Summary of Accounting Policie_3

Summary of Accounting Policies - Narrative (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Jan. 01, 2021	Dec. 31, 2020
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accumulated deficit	$ (345,162)	$ (262,551)	$ (270,313)
1.75% Convertible Senior Notes due 2023
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Debt conversion	$ 226
Revision of Prior Period, Adjustment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accumulated deficit		$ 7,762

Summary of Accounting Policie_4

Summary of Accounting Policies - Schedule of New Accounting Pronouncements & Changes in Accounting Principle (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Jan. 01, 2021	Dec. 31, 2020
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Convertible senior notes, net	$ 23,243	$ 25,205	$ 22,482
Convertible senior notes, net, noncurrent	1,212,767	648,023	488,268
Additional paid-in capital	662,894	690,316	860,556
Accumulated deficit	$ (345,162)	(262,551)	$ (270,313)
Revision of Prior Period, Adjustment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Convertible senior notes, net		2,723
Convertible senior notes, net, noncurrent		159,755
Additional paid-in capital		(170,240)
Accumulated deficit		$ 7,762

Business Combinations - Narrati

Business Combinations - Narrative (Details) - USD ($) $ in Thousands	Apr. 02, 2021	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Business Acquisition [Line Items]
Payments to acquire businesses				$ 608,000	$ 0
Acquisition-related costs		$ 202		7,925
RentPath holdings
Business Acquisition [Line Items]
Payments to acquire businesses	$ 608,000
Revenues		40,406		82,954
Net income (loss)		(18,792)	$ 23,099	(94,335)	(60,918)
RentPath holdings | Acquisition-related Costs
Business Acquisition [Line Items]
Net income (loss)		$ (23)	$ (9,151)	$ (76,118)	$ (48,224)

Business Combinations - Schedul

Business Combinations - Schedule of Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	Apr. 02, 2021	Sep. 30, 2021	Dec. 31, 2020
Business Acquisition [Line Items]
Goodwill		$ 407,228	$ 9,186
RentPath holdings
Business Acquisition [Line Items]
Cash and cash equivalents	$ 334
Accounts receivable	7,726
Prepaid expenses	5,483
Other current assets	416
Property and equipment, net	3,103
Operating lease right-of-use assets	12,330
Intangible assets	211,000
Goodwill	398,042
Total assets	638,434
Accounts payable	(1,355)
Accrued liabilities	(9,412)
Lease liabilities	(1,264)
Lease liabilities and deposits, noncurrent	(11,066)
Payroll tax liabilities, noncurrent	(1,030)
Deferred tax liabilities	(6,307)
Total liabilities	(30,434)
Total purchase consideration	$ 608,000

Business Combinations - Sched_2

Business Combinations - Schedule of Finite-Lived Intangible Assets as Part of Business Combination (Details) - USD ($) $ in Thousands	Apr. 02, 2021	Sep. 30, 2021
Trade names
Business Acquisition [Line Items]
Estimated Useful Life (in years)		10 years
Customer relationships
Business Acquisition [Line Items]
Estimated Useful Life (in years)		10 years
RentPath holdings
Business Acquisition [Line Items]
Estimated Fair Value	$ 211,000
RentPath holdings | Trade names
Business Acquisition [Line Items]
Estimated Fair Value	$ 70,000
Estimated Useful Life (in years)	10 years
RentPath holdings | Developed technology
Business Acquisition [Line Items]
Estimated Fair Value	$ 60,500
Estimated Useful Life (in years)	3 years
RentPath holdings | Customer relationships
Business Acquisition [Line Items]
Estimated Fair Value	$ 80,500
Estimated Useful Life (in years)	10 years

Business Combinations - Unaudit

Business Combinations - Unaudited Pro Forma Results (Details) - RentPath holdings - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Business Acquisition [Line Items]
Revenue	$ 540,074	$ 284,275	$ 1,322,632	$ 790,662
Net (loss) income	$ (18,792)	$ 23,099	$ (94,335)	$ (60,918)

Segment Reporting and Revenue -

Segment Reporting and Revenue - Narrative (Details)	9 Months Ended
	Sep. 30, 2021segment
Segment Reporting [Abstract]
Number of operating segments	6
Number of reportable segments	3

Segment Reporting and Revenue_2

Segment Reporting and Revenue - Reconciliation of Operating Profit (Loss) from Segments to Consolidated (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenue	$ 540,074	$ 236,916	$ 1,279,708	$ 641,576
Cost of revenue	412,772	143,844	983,912	489,586
Gross profit	127,302	93,072	295,796	151,990
Operating expenses	147,196	56,063	380,519	176,837
Interest income	178	319	472	1,859
Interest expense	(3,672)	(2,522)	(7,822)	(7,631)
Income tax benefit	311	0	5,363	0
Other income (expense), net	4,128	(640)	4,099	(1,943)
Net (loss) income	(18,949)	34,166	(82,611)	(32,562)
Real estate segment
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Gross profit	96,346	91,909	224,812	153,233
Properties segment
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Gross profit	20	(1,455)	6,640	(2,820)
Real estate and properties segments
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Operating expenses	96,910	56,063	281,569	176,837
Rentals segment
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Gross profit	33,011	0	67,989	0
Operating expenses	50,286	0	98,950	0
Operating Segments | Real estate segment
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Cost of revenue	161,449	117,944	453,790	300,305
Operating Segments | Properties segment
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenue	238,417	19,005	503,588	170,287
Cost of revenue	238,397	20,460	496,948	173,107
Operating Segments | Rentals segment
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenue	40,406	0	82,954	0
Cost of revenue	7,395	0	14,965	0
Other revenue
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenue	8,206	8,503	26,084	19,999
Cost of revenue	10,281	5,885	29,729	18,422
Gross profit	(2,075)	2,618	(3,645)	1,577
Intercompany eliminations
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenue	(4,750)	(445)	(11,520)	(2,248)
Cost of revenue	(4,750)	(445)	(11,520)	(2,248)
Brokerage revenue | Operating Segments | Real estate segment
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenue	243,575	194,375	637,532	425,269
Partner revenue | Operating Segments | Real estate segment
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenue	$ 14,220	$ 15,478	$ 41,070	$ 28,269

Financial Instruments - Narrati

Financial Instruments - Narrative (Details) - USD ($)	9 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Share price (in dollars per share)	$ 50.10
Accrued interest	$ 148,000	$ 108,000
Available-for-sale, credit loss	0	$ 0
1.75% Convertible Senior Notes due 2023
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Aggregated principal amount	23,512,000
0% Convertible Senior Notes due 2025
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Aggregated principal amount	661,250,000
0.5% Convertible Senior Notes Due 2027
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Aggregated principal amount	$ 575,000,000
Interest Rate Lock Commitments | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loan commitments, term	30 days
Interest Rate Lock Commitments | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loan commitments, term	90 days

Financial Instruments - Notiona

Financial Instruments - Notional Amounts of Derivatives (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Forward sales commitments
Derivative [Line Items]
Notional Amounts	$ 96,397	$ 130,109
IRLCs
Derivative [Line Items]
Notional Amounts	$ 94,301	$ 88,923

Financial Instruments - Amounts

Financial Instruments - Amounts of gains/(losses) recognized in income (Details) - Service revenue - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Forward sales commitments
Fair Value, Option, Quantitative Disclosures [Line Items]
Net gain recognized in earnings	$ 859	$ 553	$ 938	$ 442
IRLCs
Fair Value, Option, Quantitative Disclosures [Line Items]
Net gain recognized in earnings	$ (888)	$ (233)	$ (687)	$ 1,131

Financial Instruments - Schedul

Financial Instruments - Schedule of Assets, Liabilities, and Equity Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Fair Value, Measurements, Recurring
Assets
Cash equivalents	$ 501,432	$ 892,361
Short-term investments	28,578	131,561
Loans held for sale	42,762	42,539
Other current assets	1,698	1,815
Long-term investments	53,488	11,922
Total assets	627,958	1,080,198
Liabilities
Total liabilities	149	517
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets
Cash equivalents	501,432	892,361
Loans held for sale	0	0
Other current assets	0	0
Total assets	583,498	1,035,844
Liabilities
Total liabilities	0	0
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2)
Assets
Cash equivalents	0	0
Loans held for sale	42,762	42,539
Other current assets	552	34
Total assets	43,314	42,573
Liabilities
Total liabilities	87	507
Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3)
Assets
Cash equivalents	0	0
Loans held for sale	0	0
Other current assets	1,146	1,781
Total assets	1,146	1,781
Liabilities
Total liabilities	62	10
Fair Value, Measurements, Recurring | Money market funds
Assets
Cash equivalents	501,432	886,261
Fair Value, Measurements, Recurring | Money market funds | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets
Cash equivalents	501,432	886,261
Fair Value, Measurements, Recurring | Money market funds | Significant Other Observable Inputs (Level 2)
Assets
Cash equivalents	0	0
Fair Value, Measurements, Recurring | Money market funds | Significant Unobservable Inputs (Level 3)
Assets
Cash equivalents	0	0
Fair Value, Measurements, Recurring | U.S. treasury securities
Assets
Cash equivalents		6,100
Fair Value, Measurements, Recurring | U.S. treasury securities | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets
Cash equivalents		6,100
Fair Value, Measurements, Recurring | U.S. treasury securities | Significant Other Observable Inputs (Level 2)
Assets
Cash equivalents		0
Fair Value, Measurements, Recurring | U.S. treasury securities | Significant Unobservable Inputs (Level 3)
Assets
Cash equivalents		0
U.S. treasury securities | Fair Value, Measurements, Recurring
Assets
Short-term investments	11,981	131,561
Long-term investments	53,488	0
U.S. treasury securities | Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets
Short-term investments	11,981	131,561
Long-term investments	53,488
U.S. treasury securities | Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2)
Assets
Short-term investments	0	0
Long-term investments	0
U.S. treasury securities | Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3)
Assets
Short-term investments	0	0
Long-term investments	0
Agency bonds | Fair Value, Measurements, Recurring
Assets
Short-term investments	11,912	0
Long-term investments	0	11,922
Agency bonds | Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets
Short-term investments	11,912
Long-term investments		11,922
Agency bonds | Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2)
Assets
Short-term investments	0
Long-term investments		0
Agency bonds | Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3)
Assets
Short-term investments	0
Long-term investments		0
Equity securities
Assets
Short-term investments	4,685
Long-term investments	0
Equity securities | Fair Value, Measurements, Recurring
Assets
Short-term investments	4,685
Equity securities | Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets
Short-term investments	4,685
Equity securities | Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2)
Assets
Short-term investments	0
Equity securities | Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3)
Assets
Short-term investments	0
Forward sales commitments | Fair Value, Measurements, Recurring
Assets
Other current assets	552	34
Liabilities
Accrued liabilities	87	507
Forward sales commitments | Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets
Other current assets	0	0
Liabilities
Accrued liabilities	0	0
Forward sales commitments | Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2)
Assets
Other current assets	552	34
Liabilities
Accrued liabilities	87	507
Forward sales commitments | Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3)
Assets
Other current assets	0	0
Liabilities
Accrued liabilities	0	0
IRLCs | Fair Value, Measurements, Recurring
Assets
Other current assets	1,146	1,781
Liabilities
Accrued liabilities	62	10
IRLCs | Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets
Other current assets	0	0
Liabilities
Accrued liabilities	0	0
IRLCs | Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2)
Assets
Other current assets	0	0
Liabilities
Accrued liabilities	0	0
IRLCs | Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3)
Assets
Other current assets	1,146	1,781
Liabilities
Accrued liabilities	$ 62	$ 10

Financial Instruments - Summary

Financial Instruments - Summary of Fair Value Measurement Inputs and Valuation Techniques (Details)	Sep. 30, 2021	Dec. 31, 2020
IRLCs | Measurement Input, Weighted Average Pull Through Rate | Marketing pricing
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative instrument, measurement input (percent)	0.717	0.723

Financial Instruments - Summa_2

Financial Instruments - Summary of Changes in the Fair Value of IRLCs (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2021USD ($)
Changes of fair value of interest rate lock commitments [Roll Forward]
Balance, net—January 1, 2021	$ 1,771
Issuances of IRLCs	14,523
Settlements of IRLCs	(14,956)
Net loss recognized in earnings	(254)
Balance, net—September 30, 2021	1,084
Changes in fair value recognized during the period relating to assets still held at September 30, 2021	$ (687)

Financial Instruments - Carryin

Financial Instruments - Carrying Amounts and Estimated Fair Values of Notes (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
2023 notes
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Net Carrying Amount	$ 23,243	$ 22,482
Estimated Fair Value	38,980	59,894
2025 notes
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Net Carrying Amount	650,093	488,268
Estimated Fair Value	660,556	802,083
2027 notes
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Net Carrying Amount	562,674	0
Estimated Fair Value	$ 516,856	$ 0

Financial Instruments - Investm

Financial Instruments - Investments in Debt and Marketable Equity Securities Disclosure (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020	Sep. 30, 2020	Dec. 31, 2019
Cost or Amortized Cost
Cash and cash equivalents, at carrying value	$ 562,714	$ 925,276
Restricted cash	74,532	20,544
Cash, Cash Equivalents, Restricted Cash
Cash, cash equivalents, restricted cash and restricted cash equivalents	637,246	945,820	$ 387,966	$ 247,448
Fair Value, Measurements, Recurring
Cost or Amortized Cost
Restricted cash	74,532	20,544
Cash, cash equivalents, and available-for-sale debt securities, amortized cost	715,107	1,089,122
Unrealized Gains (Losses)
Unrealized Gains	4,213	181
Unrealized Losses	(8)	0
Estimated Fair Value
Cash equivalents	501,432	892,361
Cash, cash equivalents, and available-for-sale debt securities	719,312	1,089,303
Cash, Cash Equivalents, Restricted Cash
Cash, cash equivalents, restricted cash and restricted cash equivalents	637,246	945,820
Short-term Investments
Short-term Investments	28,578	131,561
Long-term Investments
Long-term investments	53,488	11,922
U.S. treasury securities | Fair Value, Measurements, Recurring
Cost or Amortized Cost
Debt securities, available-for-sale, amortized cost	65,461	137,502
Unrealized Gains (Losses)
Unrealized Gains	16	159
Unrealized Losses	(8)	0
Estimated Fair Value
Debt securities, available-for-sale	65,469	137,661
Short-term Investments
Short-term Investments	11,981	131,561
Long-term Investments
Long-term investments	53,488	0
Agency bonds | Fair Value, Measurements, Recurring
Cost or Amortized Cost
Debt securities, available-for-sale, amortized cost	11,900	11,900
Unrealized Gains (Losses)
Unrealized Gains	12	22
Unrealized Losses	0	0
Estimated Fair Value
Debt securities, available-for-sale	11,912	11,922
Short-term Investments
Short-term Investments	11,912	0
Long-term Investments
Long-term investments	0	11,922
Equity securities
Cost or Amortized Cost
Debt securities, available-for-sale, amortized cost	500
Unrealized Gains (Losses)
Unrealized Gains	4,185
Unrealized Losses	0
Estimated Fair Value
Debt securities, available-for-sale	4,685
Short-term Investments
Short-term Investments	4,685
Long-term Investments
Long-term investments	0
Equity securities | Fair Value, Measurements, Recurring
Short-term Investments
Short-term Investments	4,685
Cash | Fair Value, Measurements, Recurring
Cost or Amortized Cost
Cash and cash equivalents, at carrying value	61,282	32,915
Estimated Fair Value
Cash equivalents	61,282	32,915
Cash, Cash Equivalents, Restricted Cash
Cash, cash equivalents, restricted cash and restricted cash equivalents	61,282	32,915
Money markets funds | Fair Value, Measurements, Recurring
Cost or Amortized Cost
Cash and cash equivalents, at carrying value	501,432	886,261
Estimated Fair Value
Cash equivalents	501,432	886,261
Cash, Cash Equivalents, Restricted Cash
Cash, cash equivalents, restricted cash and restricted cash equivalents	501,432	886,261
U.S. treasury securities | Fair Value, Measurements, Recurring
Estimated Fair Value
Cash equivalents		6,100
Cash, Cash Equivalents, Restricted Cash
Cash, cash equivalents, restricted cash and restricted cash equivalents	$ 0	$ 6,100

Inventory (Details)

Inventory (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2021USD ($)home	Sep. 30, 2020USD ($)home	Dec. 31, 2020USD ($)
Inventory Disclosure [Abstract]
Properties for sale	$ 170,731		$ 17,153
Properties not available for sale	38,835		7,225
Properties under improvement	225,578		24,780
Inventory	435,144		49,158
Lower of cost or net realizable value write-downs	$ 2,551		$ 29
Number of homes purchased | home	1,528	253
Additions	$ 790,738	$ 101,759
Number of homes sold | home	851	370
Value of homes sold	$ 415,110	$ 149,676

Property and Equipment - Summar

Property and Equipment - Summary of Property and Equipment (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Property, Plant and Equipment [Line Items]
Accumulated depreciation and amortization	$ (54,776)	$ (41,614)
Property and equipment, net	55,535	43,988
Property and equipment, gross
Property, Plant and Equipment [Line Items]
Property and equipment, gross	102,451	79,909
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	33,467	29,558
Website and software development costs
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 46,014	33,278
Website and software development costs | Minimum
Property, Plant and Equipment [Line Items]
Useful Lives (Years)	2 years
Website and software development costs | Maximum
Property, Plant and Equipment [Line Items]
Useful Lives (Years)	3 years
Computer and office equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 13,154	7,765
Computer and office equipment | Minimum
Property, Plant and Equipment [Line Items]
Useful Lives (Years)	3 years
Computer and office equipment | Maximum
Property, Plant and Equipment [Line Items]
Useful Lives (Years)	5 years
Software
Property, Plant and Equipment [Line Items]
Useful Lives (Years)	3 years
Property and equipment, gross	$ 1,871	1,858
Furniture
Property, Plant and Equipment [Line Items]
Useful Lives (Years)	7 years
Property and equipment, gross	$ 7,945	7,450
Construction in progress
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 7,860	$ 5,693

Property and Equipment - Narrat

Property and Equipment - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Property, Plant and Equipment [Abstract]
Depreciation and amortization	$ 5,399	$ 3,594	$ 14,369	$ 10,215
Capitalized computer software, additions	$ 4,727	$ 2,773	$ 13,137	$ 8,286

Leases - Narrative (Details)

Leases - Narrative (Details)	Sep. 30, 2021
Vehicles
Lessee, Lease, Description [Line Items]
Finance lease term (in years)	4 years
Minimum
Lessee, Lease, Description [Line Items]
Operating lease term (in years)	1 year
Maximum
Lessee, Lease, Description [Line Items]
Operating lease term (in years)	11 years

Leases - Summary of Lease Cost

Leases - Summary of Lease Cost (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Operating Leased Assets [Line Items]
Operating lease cost	$ 4,127	$ 3,210	$ 11,545	$ 9,679
Total finance lease cost	160	19	386	58
Short-term lease cost	430	218	1,156	712
Cost of revenue
Operating Leased Assets [Line Items]
Operating lease cost	2,400	2,123	7,105	6,405
Finance lease, right-of-use asset, amortization	139	2	335	7
Finance lease, interest expense	21	17	51	51
Operating expenses
Operating Leased Assets [Line Items]
Operating lease cost	$ 1,727	$ 1,087	$ 4,440	$ 3,274

Leases - Maturity of Lease Liab

Leases - Maturity of Lease Liabilities (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2021USD ($)
Operating leases
2021, excluding the nine months ended September 30, 2021	$ 4,397
2022	16,852
2023	15,779
2024	14,324
2025	11,189
Thereafter	16,929
Total lease payments	79,470
Less: Interest	8,316
Present value of lease liabilities	71,154
Finance leases
2021, excluding the nine months ended September 30, 2021	120
2022	478
2023	465
2024	379
2025	80
Thereafter	0
Total lease payments	1,522
Less: Interest	124
Present value of lease liabilities	1,398
Other Leases
2021, excluding the nine months ended September 30, 2021	256
2022	467
2023	0
2024	0
2025	0
Thereafter	0
Total lease payments	723
Total Lease Obligations
2021, excluding the nine months ended September 30, 2021	4,773
2022	17,797
2023	16,244
2024	14,703
2025	11,269
Thereafter	16,929
Total lease payments	81,715
Operating lease, capitalized interest expense	2,788
Financing lease, capitalized interest expense	$ 66

Leases - Lease Term and Discoun

Leases - Lease Term and Discount Rate (Details)	Sep. 30, 2021	Dec. 31, 2020
Leases [Abstract]
Weighted-average remaining operating lease term (years)	5 years 1 month 6 days	5 years 2 months 12 days
Weighted-average remaining finance lease term (years)	3 years 3 months 18 days	3 years 6 months
Weighted average discount rate for operating leases (percent)	4.40%	4.40%
Weighted average discount rate for finance leases (percent)	5.40%	5.40%

Leases - Supplemental Cash Flow

Leases - Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Cash paid for amounts included in the measurement of lease liabilities
Operating cash flows from operating leases	$ 12,006	$ 10,584
Operating cash flows from finance leases	64	7
Financing cash flows from finance leases	226	38
Right of use assets obtained in exchange for lease liabilities
Operating leases	6,544	354
Finance leases	$ 987	$ 0

Commitments and Contingencies -

Commitments and Contingencies - Narrative (Details) $ in Thousands	Sep. 30, 2021USD ($)	Apr. 06, 2021employee
Debt Instrument [Line Items]
Payments remainder of fiscal year | $	$ 137,325
Employment Claim
Debt Instrument [Line Items]
Number of former employees		2
Number of current employees		1

Acquired Intangible Assets an_3

Acquired Intangible Assets and Goodwill - Schedule of Finite-Lived Intangible Assets (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Finite-Lived Intangible Assets [Line Items]
Gross	$ 215,880	$ 4,880
Accumulated Amortization	(21,024)	(3,050)
Net	$ 194,856	1,830
Trade names
Finite-Lived Intangible Assets [Line Items]
Weighted-Average Useful Lives (Years)	10 years
Gross	$ 71,040	1,040
Accumulated Amortization	(4,228)	(650)
Net	66,812	390
Developed technology
Finite-Lived Intangible Assets [Line Items]
Gross	63,480	2,980
Accumulated Amortization	(12,169)	(1,862)
Net	$ 51,311	1,118
Developed technology | Minimum
Finite-Lived Intangible Assets [Line Items]
Weighted-Average Useful Lives (Years)	3 years 3 months 18 days
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Weighted-Average Useful Lives (Years)	10 years
Gross	$ 81,360	860
Accumulated Amortization	(4,627)	(538)
Net	$ 76,733	$ 322

Acquired Intangible Assets an_4

Acquired Intangible Assets and Goodwill - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization expense	$ 8,926	$ 122	$ 17,974	$ 366

Acquired Intangible Assets an_5

Acquired Intangible Assets and Goodwill - Amortization Expense (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
2021, excluding the nine months ended September 30, 2021	$ 8,926
2022	35,705
2023	35,705
2024	20,458
2025	15,050
Thereafter	79,012
Net	$ 194,856	$ 1,830

Acquired Intangible Assets an_6

Acquired Intangible Assets and Goodwill - Schedule of Goodwill (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2021USD ($)
Goodwill [Roll Forward]
Balance as of December 31, 2020	$ 9,186
Balance as of September 30, 2021	407,228
RentPath holdings
Goodwill [Roll Forward]
Goodwill resulting from acquisition	$ 398,042

Accrued Liabilities (Details)

Accrued Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Payables and Accruals [Abstract]
Accrued compensation and benefits	$ 68,230	$ 49,238
Miscellaneous accrued liabilities	20,015	9,722
Payroll tax liability deferred by the CARES Act	7,841	6,812
Customer contract liabilities	5,941	3,688
Accrued liabilities	$ 102,027	$ 69,460

Other Payables (Details)

Other Payables (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Payables and Accruals [Abstract]
Customer deposits	$ 14,344	$ 11,183
Miscellaneous payables	2,422	2,001
Total other payables	$ 16,766	$ 13,184

Mezzanine Equity (Details)

Mezzanine Equity (Details) $ / shares in Units, $ in Thousands	Apr. 01, 2020USD ($)$ / sharesshares	Sep. 30, 2021USD ($)$ / sharesshares	Sep. 30, 2021USD ($)tradingDay$ / sharesshares	Sep. 30, 2020USD ($)shares	Jun. 30, 2021USD ($)	Dec. 31, 2020USD ($)	Jun. 30, 2020USD ($)	Dec. 31, 2019USD ($)
Temporary Equity [Line Items]
Issuance of common stock, net | $	$ 110,000			$ 69,701
Carrying value of convertible preferred stock | $		$ 39,857	$ 39,857			$ 39,823
Temporary equity, dividends (in shares) | shares		30,640
Convertible preferred stock, shares issued upon conversion (in shares) | shares	2,622,177
Preferred stock, dividend rate (percent)			0.055%
Preferred stock, dividend rate (in dollars per share) | $ / shares			$ 17.95
Conversion price ratio denominator (in dollars per share) | $ / shares		$ 19.51	19.51
Conversion stock price trigger (in dollars per share) | $ / shares			$ 27.32
Threshold consecutive trading days | tradingDay			30
Common Stock
Temporary Equity [Line Items]
Stock issued during period shares new issues (in shares) | shares	4,484,305			4,484,305
Shares issued price per share (in dollar per share) | $ / shares	$ 15.61
Issuance of common stock, net | $				$ 4
Series A Convertible Preferred Stock
Temporary Equity [Line Items]
Stock issued during period shares new issues (in shares) | shares	40,000
Shares issued price per share (in dollar per share) | $ / shares	$ 1,000
Issuance of common stock, net | $	$ 40,000
Carrying value of convertible preferred stock | $		$ 39,857	$ 39,857	$ 39,812	$ 39,846	$ 39,823	$ 39,801	$ 0
Converted preferred stock (in shares) | shares			0

Equity and Equity Compensatio_3

Equity and Equity Compensation Plans - Narrative (Details) - USD ($) $ / shares in Units, $ in Thousands	Jun. 01, 2019	Jul. 27, 2017	Sep. 30, 2021	Dec. 31, 2020	Jul. 26, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, authorized (in shares)			500,000,000	500,000,000
Common stock, par value (in dollars per share)			$ 0.001	$ 0.001
Temporary equity, shares authorized (in shares)			10,000,000	10,000,000
Temporary equity, par value (in dollars per share)			$ 0.001	$ 0.001
Unrecognized stock-based compensation, options			$ 95
2004 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected life (years)			10 years
Award vesting period (years)			4 years
2017 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved (in shares)			24,545,660	21,502,858	7,898,159
Expected life (years)			10 years
Percentage of common stock, outstanding			5.00%
Restricted stock units outstanding (in shares)			3,452,462	4,459,743
2017 Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved (in shares)			3,904,241	3,009,662
Employee stock | 2004 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved (in shares)			0
Employee stock | 2017 Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved (in shares)		1,600,000
Percentage of common stock, outstanding		1.00%
Purchase price of common stock, percentage of market price of common stock			85.00%
Share-based Payment Arrangement, Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense, period for recognition (years)			3 months
Performance Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock units outstanding (in shares)			331,759
Achievement percentage of performance conditions			100.00%
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized stock-based compensation			$ 99,783
Unrecognized compensation expense, period for recognition (years)			2 years 3 months 14 days
Restricted stock units outstanding (in shares)			3,452,462	4,459,743
Chief Executive Officer | Performance Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted (in shares)	150,000		150,000
Options granted (in dollars per share)	$ 27.50
Minimum | 2017 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period (years)			2 years
Minimum | Performance Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of target amount			0.00%
Maximum | 2017 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period (years)			4 years
Maximum | Performance Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of target amount			200.00%
Maximum | Chief Executive Officer | Performance Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted (in shares)	300,000
Options vested (in shares)			0

Equity and Equity Compensatio_4

Equity and Equity Compensation Plans - Summary of Common Stock Reserved for Future Issuance: 2017 EIP (Details) - shares	Sep. 30, 2021	Dec. 31, 2020	Jul. 26, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options issued and outstanding options (in shares)	4,374,257	5,733,738
Equity Incentive Plans
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options issued and outstanding options (in shares)	4,374,257	5,733,738
Restricted stock units issued and outstanding or deferred (in shares)	3,452,462	4,459,743
Shares available for future equity grants (in shares)	16,718,941	11,309,377
Total shares reserved for future issuance (in shares)	24,545,660	21,502,858	7,898,159

Equity and Equity Compensatio_5

Equity and Equity Compensation Plans - Summary of Common Stock Reserved for Future Issuance: 2017 ESPP (Details) - 2017 Employee Stock Purchase Plan - shares	Sep. 30, 2021	Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for issuance at beginning of period (in shares)	4,039,667	3,330,271
Shares issued during the period (in shares)	(135,426)	(320,609)
Total shares reserved for future issuance (in shares)	3,904,241	3,009,662

Equity and Equity Compensatio_6

Equity and Equity Compensation Plans - Schedule of Stock Option Activity (Details) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2021USD ($)$ / sharesshares	Dec. 31, 2020USD ($)$ / sharesshares
Number of Options
Outstanding, beginning balance (in shares) | shares	5,733,738
Options exercised (in shares) | shares	(1,354,078)
Options forfeited (in shares) | shares	(290)
Options canceled (in shares) | shares	(5,113)
Outstanding, ending balance (in shares) | shares	4,374,257	5,733,738
Options exercisable at period end (in shares) | shares	4,224,257
Weighted-Average Exercise Price
Outstanding, beginning balance (in dollars per share) | $ / shares	$ 7.23
Options exercised (in dollars per share) | $ / shares	5.10
Options forfeited (in dollars per share) | $ / shares	10.80
Options canceled (in dollars per share) | $ / shares	10.80
Outstanding, ending balance (in dollars per share) | $ / shares	7.88	$ 7.23
Options exercisable at period end (in dollars per share) | $ / shares	$ 7.18
Weighted-Average Remaining Contractual Life (Years)
Weighted average remaining contractual life outstanding	3 years 11 months 1 day	4 years 4 months 20 days
Weighted average remaining contractual life exercisable	3 years 9 months 10 days
Aggregate Intrinsic Value
Options outstanding, Aggregate intrinsic value | $	$ 184,685	$ 352,076
Options exercisable, Aggregate intrinsic value | $	$ 181,295

Equity and Equity Compensatio_7

Equity and Equity Compensation Plans - Schedule of Restricted Stock Unit Activity (Details) - Restricted Stock Units (RSUs)	9 Months Ended
	Sep. 30, 2021$ / sharesshares
Restricted Stock Units
Unvested outstanding at beginning of period (in shares) | shares	4,459,743
Granted (in shares) | shares	658,610
Vested (in shares) | shares	(1,072,378)
Forfeited or canceled (in shares) | shares	(593,513)
Unvested outstanding at end of period (in shares) | shares	3,452,462
Weighted-Average Grant-Date Fair Value
Unvested outstanding at beginning of period (in dollars per share) | $ / shares	$ 27.44
Granted (in dollars per share) | $ / shares	55.89
Vested (in dollars per share) | $ / shares	22.39
Forfeited or canceled (in dollars per share) | $ / shares	26.42
Unvested outstanding at end of period (in dollars per share) | $ / shares	$ 34.62

Equity and Equity Compensatio_8

Equity and Equity Compensation Plans - Compensation Costs for PSU's (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total expense	$ 13,110	$ 11,348	$ 39,438	$ 25,764
Performance Restricted Stock Units
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total expense			4,465	(126)
Performance Restricted Stock Units | Current Period
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total expense			4,465	(610)
Performance Restricted Stock Units | Prior Periods
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total expense			$ 0	$ 484

Equity and Equity Compensatio_9

Equity and Equity Compensation Plans - Allocation of Stock-based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation	$ 13,110	$ 11,348	$ 39,438	$ 25,764
Stock-based compensation capitalized in property and equipment	1,028	563	2,745	1,714
Cost of revenue
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation	3,283	2,574	10,019	5,981
Technology and development
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation	5,455	4,964	16,987	11,736
Marketing
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation	537	403	1,615	1,130
General and administrative
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation	$ 3,835	$ 3,407	$ 10,817	$ 6,917

Net (Loss) Income per Share A_3

Net (Loss) Income per Share Attributable to Common Stock - Computation of Net Loss Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Numerator:
Net (loss) income	$ (18,949)	$ 34,166	$ (82,611)	$ (32,562)
Dividends on convertible preferred stock	(1,662)	(1,530)	(5,875)	(2,814)
Undistributed earnings attributable to participating securities, diluted	0	(653)	0	0
Undistributed earnings attributable to participating securities, basic	0	(653)	0	0
Net loss attributable to common stock - basic	(20,611)	31,983	(88,486)	(35,376)
Net loss attributable to common stock - diluted	$ (20,611)	$ 31,983	$ (88,486)	$ (35,376)
Denominator:
Weighted average shares - basic (in shares)	105,144,872	99,840,144	104,327,614	97,365,122
Dilutive shares from stock plans (in shares)	0	7,767,567	0	0
Weighted averages shares - diluted (in shares)	105,144,872	107,607,711	104,327,614	97,365,122
Earnings Per Share, Basic and Diluted [Abstract]
Net loss per share attributable to common stock - basic (in dollars per share)	$ (0.20)	$ 0.32	$ (0.85)	$ (0.36)
Net loss per share attributable to common stock - diluted (in dollars per share)	$ (0.20)	$ 0.30	$ (0.85)	$ (0.36)

Net (Loss) Income per Share A_4

Net (Loss) Income per Share Attributable to Common Stock - Summary of Anti-dilutive Stock Equivalents (Details) - USD ($) $ in Thousands	Jun. 01, 2019	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from earnings per share (in shares)		26,029,681	6,745,398	26,029,681	16,732,739
Performance Restricted Stock Units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Restricted stock units issued and outstanding or deferred (in shares)		331,759		331,759
Performance Restricted Stock Units | Maximum
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Percentage of target amount				200.00%
Chief Executive Officer | Performance Restricted Stock Units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Options granted (in shares)	150,000			150,000
Chief Executive Officer | Performance Restricted Stock Units | Maximum
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Options granted (in shares)	300,000
Convertible Preferred Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from earnings per share (in shares)		2,040,000	2,040,000	2,040,000	2,040,000
Share-based Payment Arrangement, Option
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from earnings per share (in shares)		4,374,257	0	4,374,257	5,924,213
Restricted Stock Units (RSUs)
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from earnings per share (in shares)		3,424,733	0	3,424,733	3,932,539
Restricted Stock Units (RSUs) | Non-employee Directors
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from earnings per share (in shares)				27,729
Employee stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from earnings per share (in shares)		153,208	0	153,208	130,589
1.75% Convertible Senior Notes due 2023
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from earnings per share (in shares)		769,623	4,705,398	769,623	4,705,398
Debt conversion				$ 226
0% Convertible Senior Notes due 2025
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from earnings per share (in shares)		9,119,960	0	9,119,960	0
0.5% Convertible Senior Notes Due 2027
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from earnings per share (in shares)		6,147,900	0	6,147,900	0

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Thousands	Apr. 02, 2021	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020	Jun. 30, 2017
Operating Loss Carryforwards [Line Items]
Income tax benefit		$ 311	$ 0	$ 5,363	$ 0
Effective tax rate (percent)				6.10%	0.00%
Operating loss unavailable for carryforward							$ 1,538
Federal Jurisdiction
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards						$ 227,751
Operating loss carryforwards, not subject to expiration						142,420
Federal Jurisdiction | RentPath Holdings
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	$ 252,792
Federal deductible	142,632
Operating loss carryforwards, not subject to expiration	$ 42,911
State and Local Jurisdiction
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards						12,576
Foreign Tax Authority
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards						$ 2,050

Debt - Warehouse Lines of Credi

Debt - Warehouse Lines of Credit (Details) - USD ($)	Sep. 30, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Outstanding Borrowings	$ 39,825,000	$ 39,029,000
Warehouse Agreement Borrowings
Debt Instrument [Line Items]
Borrowing Capacity	105,000,000	105,000,000
Outstanding Borrowings	$ 39,825,000	$ 39,029,000
Weighted-Average Interest Rate on Outstanding Borrowings	0.00%	0.00%
Western Alliance Bank | Warehouse Agreement Borrowings
Debt Instrument [Line Items]
Borrowing Capacity	$ 50,000,000	$ 50,000,000
Outstanding Borrowings	$ 16,369,000	$ 18,277,000
Weighted-Average Interest Rate on Outstanding Borrowings	3.25%	3.25%
Texas Capital Bank, N.A. | Warehouse Agreement Borrowings
Debt Instrument [Line Items]
Borrowing Capacity	$ 40,000,000	$ 40,000,000
Outstanding Borrowings	$ 15,674,000	$ 12,903,000
Weighted-Average Interest Rate on Outstanding Borrowings	2.98%	3.35%
Flagstar Bank, FSB | Warehouse Agreement Borrowings
Debt Instrument [Line Items]
Borrowing Capacity	$ 15,000,000	$ 15,000,000
Outstanding Borrowings	$ 7,782,000	$ 7,849,000
Weighted-Average Interest Rate on Outstanding Borrowings	3.00%	3.00%

Debt - Narrative (Details)

Debt - Narrative (Details) $ / shares in Units, $ in Thousands	Mar. 25, 2021USD ($)$ / sharesshares	Jan. 12, 2021	Sep. 30, 2021USD ($)shares	Mar. 31, 2021	Sep. 30, 2020USD ($)	Sep. 30, 2021USD ($)tradingDaybusinessDay	Sep. 30, 2020USD ($)	Dec. 31, 2020USD ($)	Oct. 20, 2020USD ($)	Dec. 31, 2019USD ($)	Jul. 23, 2018USD ($)
Debt Instrument [Line Items]
Inventory			$ 435,144			$ 435,144		$ 49,158
Cash, cash equivalents, restricted cash and restricted cash equivalents			637,246		$ 387,966	637,246	$ 387,966	945,820		$ 247,448
Proceeds from issuance of convertible senior notes, net of issuance costs						561,529	0
Adjustments to additional paid in capital, convertible debt, capped call transaction			62,647			$ 62,647
Debt Instrument, Redemption, Period Two
Debt Instrument [Line Items]
Conversion price, percentage						98.00%
1.75% Convertible Senior Notes due 2023
Debt Instrument [Line Items]
Aggregated principal amount			23,512			$ 23,512
Debt conversion						226
Converted instrument			$ 234
Common stock (in shares) | shares			3,164
0% Convertible Senior Notes due 2025
Debt Instrument [Line Items]
Aggregated principal amount			$ 661,250			661,250
0.5% Convertible Senior Notes Due 2027
Debt Instrument [Line Items]
Aggregated principal amount			575,000			575,000
Revolving Credit Facility
Debt Instrument [Line Items]
Net assets			511,569			511,569		65,191
Inventory			415,610			415,610		47,620
Cash, cash equivalents, restricted cash and restricted cash equivalents			25,446			25,446		11,818
Amortization of debt issuance costs			81		155	217	464
Interest expense, debt			$ 1,375		101	$ 2,328	432
Western Alliance Bank | Warehouse Agreement Borrowings
Debt Instrument [Line Items]
Stated Cash Interest Rate			3.25%			3.25%
Western Alliance Bank | Warehouse Agreement Borrowings | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate						2.00%
Texas Capital Bank, N.A. | Warehouse Agreement Borrowings
Debt Instrument [Line Items]
Stated Cash Interest Rate			2.95%			2.95%
Decrease in rate of interest accruing on outstanding principal						0.25%
Flagstar Bank, FSB | Warehouse Agreement Borrowings
Debt Instrument [Line Items]
Stated Cash Interest Rate			3.00%			3.00%
Facility termination period						30 days
Flagstar Bank, FSB | Warehouse Agreement Borrowings | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate						2.00%
Goldman Sachs Bank USA | Revolving Credit Facility
Debt Instrument [Line Items]
Debt instrument, term						6 months
Minimum | Goldman Sachs Bank USA | Revolving Credit Facility
Debt Instrument [Line Items]
Debt instrument, floor rate of basis spread on variable rate		0.50%		0.30%
Maximum | Goldman Sachs Bank USA | Revolving Credit Facility
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate				3.00%
Senior Notes
Debt Instrument [Line Items]
Amortization of debt issuance costs			$ 1,291		189	$ 3,366	562
Interest expense, debt			$ 822		629	$ 1,779	1,887
Senior Notes | 1.75% Convertible Senior Notes due 2023
Debt Instrument [Line Items]
Stated Cash Interest Rate			1.75%			1.75%
Amortization of debt issuance costs			$ 41		189	$ 151	562
Interest expense, debt			103		629	311	1,887
Aggregated principal amount			23,512			23,512		25,626			$ 143,750
Repurchased face amount			120,238			120,238
Senior Notes | 0% Convertible Senior Notes due 2025
Debt Instrument [Line Items]
Amortization of debt issuance costs			690		0	2,070	0
Interest expense, debt			0		0	0	0
Aggregated principal amount			$ 661,250			$ 661,250		$ 661,250	$ 661,250
Senior Notes | 0.5% Convertible Senior Notes Due 2027
Debt Instrument [Line Items]
Stated Cash Interest Rate			0.50%			0.50%
Amortization of debt issuance costs			$ 560		0	$ 1,145	0
Interest expense, debt			719		$ 0	1,468	$ 0
Aggregated principal amount	$ 575,000		$ 575,000			$ 575,000
Proceeds from issuance of convertible senior notes, net of issuance costs	$ 561,529
Common stock covered under capped calls (in shares) | shares	6,147,900
Senior Notes | Convertible Senior Notes | Debt Instrument, Redemption, Period One
Debt Instrument [Line Items]
Threshold trading days | tradingDay						20
Threshold consecutive trading days | tradingDay						30
Threshold percentage of stock price trigger						130.00%
Senior Notes | Convertible Senior Notes | Debt Instrument, Redemption, Period Two
Debt Instrument [Line Items]
Threshold trading days | businessDay						5
Threshold consecutive trading days | tradingDay						5
Senior Notes | Minimum | 0.5% Convertible Senior Notes Due 2027 | Call Option | Capped Call Transaction
Debt Instrument [Line Items]
Capped call price (in dollars per share) | $ / shares	$ 93.53
Senior Notes | Maximum | 0.5% Convertible Senior Notes Due 2027 | Call Option | Capped Call Transaction
Debt Instrument [Line Items]
Capped call price (in dollars per share) | $ / shares	$ 138.56

Debt - Secured Revolving Credit

Debt - Secured Revolving Credit Facility (Details) - Goldman Sachs Bank USA - Revolving Credit Facility - USD ($)	Sep. 30, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Borrowing Capacity	$ 200,000,000	$ 100,000,000
Outstanding Borrowings	$ 199,627,000	$ 23,949,000
Weighted-Average Interest Rate on Outstanding Borrowings	3.30%	4.40%

Debt - Convertible Senior Notes

Debt - Convertible Senior Notes (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2021USD ($)	Mar. 25, 2021USD ($)	Dec. 31, 2020USD ($)	Oct. 20, 2020USD ($)	Jul. 23, 2018USD ($)
1.75% Convertible Senior Notes due 2023
Debt Instrument [Line Items]
Aggregate Principal Amount	$ 23,512
Net Carrying Amount	$ 23,243		$ 22,482
1.75% Convertible Senior Notes due 2023 | Senior Notes
Debt Instrument [Line Items]
Stated Cash Interest Rate	1.75%
Effective Interest Rate	2.45%
Conversion Rate	32.7332
Aggregate Principal Amount	$ 23,512		25,626		$ 143,750
Repurchased face amount	120,238
Unamortized Debt Discount	0		2,776
Unamortized Debt Issuance Costs	269		368
Net Carrying Amount	23,243		22,482
0% Convertible Senior Notes due 2025
Debt Instrument [Line Items]
Aggregate Principal Amount	661,250
Net Carrying Amount	$ 650,093		488,268
0% Convertible Senior Notes due 2025 | Senior Notes
Debt Instrument [Line Items]
Effective Interest Rate	0.42%
Conversion Rate	13.7920
Aggregate Principal Amount	$ 661,250		661,250	$ 661,250
Unamortized Debt Discount	0		163,077
Unamortized Debt Issuance Costs	11,157		9,905
Net Carrying Amount	650,093		488,268
0.5% Convertible Senior Notes Due 2027
Debt Instrument [Line Items]
Aggregate Principal Amount	575,000
Net Carrying Amount	$ 562,674		$ 0
0.5% Convertible Senior Notes Due 2027 | Senior Notes
Debt Instrument [Line Items]
Stated Cash Interest Rate	0.50%
Effective Interest Rate	0.90%
Conversion Rate	10.6920
Aggregate Principal Amount	$ 575,000	$ 575,000
Unamortized Debt Discount	0
Unamortized Debt Issuance Costs	12,326
Net Carrying Amount	$ 562,674

Debt - Interest Expense (Detail

Debt - Interest Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Debt Instrument [Line Items]
Total interest expense	$ 3,672	$ 2,522	$ 7,822	$ 7,631
Senior Notes
Debt Instrument [Line Items]
Contractual interest expense	822	629	1,779	1,887
Amortization of debt discount	0	1,422	0	4,217
Amortization of debt issuance costs	1,291	189	3,366	562
Total interest expense	2,113	2,240	5,145	6,666
1.75% Convertible Senior Notes due 2023 | Senior Notes
Debt Instrument [Line Items]
Contractual interest expense	103	629	311	1,887
Amortization of debt discount	0	1,422	0	4,217
Amortization of debt issuance costs	41	189	151	562
Total interest expense	144	2,240	462	6,666
0% Convertible Senior Notes due 2025 | Senior Notes
Debt Instrument [Line Items]
Contractual interest expense	0	0	0	0
Amortization of debt discount	0	0	0	0
Amortization of debt issuance costs	690	0	2,070	0
Total interest expense	690	0	2,070	0
0.5% Convertible Senior Notes Due 2027 | Senior Notes
Debt Instrument [Line Items]
Contractual interest expense	719	0	1,468	0
Amortization of debt discount	0	0	0	0
Amortization of debt issuance costs	560	0	1,145	0
Total interest expense	$ 1,279	$ 0	$ 2,613	$ 0

Subsequent Events (Details)

Subsequent Events (Details) - Warehouse Agreement Borrowings - USD ($)	Nov. 01, 2021	Sep. 30, 2021	Dec. 31, 2020
Subsequent Event [Line Items]
Borrowing Capacity		$ 105,000,000	$ 105,000,000
Flagstar Bank, FSB
Subsequent Event [Line Items]
Borrowing Capacity		$ 15,000,000	$ 15,000,000
Subsequent Event | Flagstar Bank, FSB
Subsequent Event [Line Items]
Borrowing Capacity	$ 25,000