Redfin (RDFN) 10-Q 7 May 20 2020 Q1 Quarterly report Financial data

Cover Page

Cover Page - shares	3 Months Ended
	Mar. 31, 2020	Apr. 30, 2020
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2020
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		98,481,863
Entity Central Index Key	0001382821
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q1
Amendment Flag	false

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Current assets
Cash and cash equivalents	$ 213,940	$ 234,679
Restricted cash	16,772	12,769
Short-term investments	75,049	70,029
Accounts receivable, net	21,821	19,223
Inventory	70,649	74,590
Loans held for sale	44,321	21,985
Prepaid expenses	9,555	14,822
Other current assets	5,243	3,496
Total current assets	457,350	451,593
Property and equipment, net	40,496	39,577
Right-of-use assets, net	49,972	52,004
Long-term investments	26,711	30,978
Goodwill and intangibles, net	11,382	11,504
Other non-current assets	8,923	10,557
Total assets	594,834	596,213
Current liabilities
Accounts payable	2,909	2,122
Accrued liabilities	58,456	38,022
Other payables	11,717	7,884
Warehouse credit facilities	42,586	21,302
Secured revolving credit facility	8,901	4,444
Current lease liabilities	11,533	11,408
Total current liabilities	136,102	85,182
Non-current lease liabilities	57,254	59,869
Convertible senior notes, net	121,292	119,716
Total liabilities	314,648	264,767
Commitments and contingencies (Note 7)
Stockholders’ equity
Common stock—par value $0.001 per share; 500,000,000 shares authorized; 93,957,774 and 93,001,597 shares issued and outstanding, respectively	94	93
Additional paid-in capital	591,421	583,097
Accumulated other comprehensive income	575	42
Accumulated deficit	(311,904)	(251,786)
Total stockholders’ equity	280,186	331,446
Total liabilities and stockholders’ equity	$ 594,834	$ 596,213

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Mar. 31, 2020	Dec. 31, 2019
Statement of Financial Position [Abstract]
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)	93,957,774	93,001,597
Common stock, outstanding (in shares)	93,957,774	93,001,597

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Revenue	$ 190,995	$ 110,141
Cost of revenue	178,116	107,388
Gross profit	12,879	2,753
Operating expenses
Technology and development	20,274	15,556
Marketing	25,708	33,201
General and administrative	24,327	21,448
Total operating expenses	70,309	70,205
Loss from operations	(57,430)	(67,452)
Interest income	1,103	2,316
Interest expense	(2,444)	(2,136)
Other income (expense), net	(1,346)	92
Net loss	$ (60,117)	$ (67,180)
Net loss per share attributable to common stock—basic and diluted (in dollars per share)	$ (0.64)	$ (0.74)
Weighted average shares of common stock - basic and diluted (in shares)	93,442,706	90,610,416
Other comprehensive income
Foreign currency translation adjustments	$ (25)	$ 1
Unrealized gain on available-for-sale securities	559	0
Total comprehensive loss	(59,583)	(67,179)
Service
Revenue	111,478	88,768
Cost of revenue	98,368	84,395
Product
Revenue	79,517	21,373
Cost of revenue	$ 79,748	$ 22,993

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Sep. 30, 2019	Sep. 30, 2018
Operating Activities
Net loss	$ (60,117)	$ (67,180)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	3,307	1,637
Stock-based compensation	7,211	6,406
Amortization of debt discount and issuance costs	1,730	1,507
Non-cash lease expense	2,254	1,216
Impairment costs	1,420	0
Other	(989)	0
Change in assets and liabilities:
Accounts receivable, net	(2,598)	(890)
Inventory	3,941	(15,612)
Prepaid expenses and other assets	3,409	1,441
Accounts payable	514	14,848
Accrued liabilities and other payables	20,626	21,764
Lease liabilities	(2,693)	(1,459)
Origination of loans held for sale	(132,697)	(49,850)
Proceeds from sale of loans originated as held for sale	111,233	39,015
Net cash used in operating activities	(43,449)	(47,157)
Investing activities
Purchases of property and equipment	(3,406)	(3,151)
Purchases of investments	(33,267)	0
Sales of investments	31,608	0
Maturities of investments	1,597	0
Net cash used in investing activities	(3,468)	(3,151)
Financing activities
Proceeds from the issuance of shares resulting from employee equity plans	4,103	3,732
Tax payments related to net share settlements on restricted stock units	(3,307)	(818)
Borrowings from warehouse credit facilities	131,310	48,557
Repayments to warehouse credit facilities	(110,025)	(38,097)
Borrowings from secured revolving credit facility	11,854	0
Repayments to secured revolving credit facility	(7,398)	0
Other payables—deposits held in escrow	3,684	3,968
Principal payments for finance lease obligations	(15)	0
Net cash provided by financing activities	30,206	17,342
Effect of exchange rate changes on cash and cash equivalents	(25)	0
Net change in cash, cash equivalents, and restricted cash	(16,736)	(32,966)
Cash, cash equivalents, and restricted cash:
Beginning of period	247,448	439,055	$ 439,055
End of period	230,712	406,089
Supplemental disclosure of cash flow information
Cash paid for interest	1,582	1,202
Non-cash transactions
Stock-based compensation capitalized in property and equipment	504	270
Property and equipment additions in accounts payable and accrued liabilities			$ 451	$ 1,370
Leasehold improvements paid directly by lessor	$ 0	$ 1,963

Consolidated Statements of Chan

Consolidated Statements of Changes in Stockholders’ Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive Income
Beginning balance (in shares) at Dec. 31, 2018		90,151,341
Beginning balance at Dec. 31, 2018	$ 371,938	$ 90	$ 542,829	$ (170,981)	$ 0
Increase (Decrease) in Stockholders' Equity
Issuance of common stock pursuant to exercise of stock options (in shares)		679,495
Issuance of common stock pursuant to exercise of stock options	3,732	$ 1	3,731
Issuance of common stock pursuant to settlement of restricted stock units (in shares)		139,889
Issuance of common stock pursuant to settlement of restricted stock units	0
Common stock surrendered for employees' tax liability upon settlement of restricted stock units (in shares)		(44,476)
Common stock surrendered for employees' tax liability upon settlement of restricted stock units	(818)		(818)
Stock-based compensation	6,676		6,676
Other comprehensive income	1				1
Net loss	(67,180)			(67,180)
Ending balance (in shares) at Mar. 31, 2019		90,926,249
Ending balance at Mar. 31, 2019	$ 314,349	$ 91	552,418	(238,160)	1
Beginning balance (in shares) at Dec. 31, 2019	93,001,597	93,001,597
Beginning balance at Dec. 31, 2019	$ 331,446	$ 93	583,097	(251,786)	42
Increase (Decrease) in Stockholders' Equity
Issuance of common stock pursuant to exercise of stock options (in shares)	738,398	738,398
Issuance of common stock pursuant to exercise of stock options	$ 3,916	$ 1	3,915
Issuance of common stock pursuant to settlement of restricted stock units (in shares)		320,440
Issuance of common stock pursuant to settlement of restricted stock units	0
Common stock surrendered for employees' tax liability upon settlement of restricted stock units (in shares)		(102,661)
Common stock surrendered for employees' tax liability upon settlement of restricted stock units	(3,307)		(3,307)
Stock-based compensation	7,715		7,715
Other comprehensive income	533				533
Net loss	$ (60,117)			(60,117)
Ending balance (in shares) at Mar. 31, 2020	93,957,774	93,957,774
Ending balance at Mar. 31, 2020	$ 280,186	$ 94	$ 591,420	$ (311,903)	$ 575

Summary of Accounting Policies

Summary of Accounting Policies	3 Months Ended
	Mar. 31, 2020
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, 2019 that is included in this quarterly report is derived from the audited consolidated financial statements and notes for the year ended December 31, 2019 included in Item 8 in our annual report for the year ended December 31, 2019 . 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 March 31, 2020 , the statements of comprehensive loss and stockholders' equity for the three months ended March 31, 2020 and 2019 , and the statement of cash flows for the three months ended March 31, 2020 and 2019 . The results for the three months ended March 31, 2020 are not necessarily indicative of the results to be expected for the year ending December 31, 2020 or for any interim period or for any other future year. Principles of Consolidation —The unaudited consolidated interim financial statements include the accounts of Redfin 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. COVID-19 Risks, Impacts and Uncertainties —We are subject to the risks arising from COVID-19's social and economic impacts on the residential real estate industry. Our management believes that these social and economic impacts, which include but are not limited to the following, could have a significant negative impact on our future financial position, results of operations, and cash flows: (i) restrictions on in-person activities associated with residential real estate transactions arising from shelter-in-place, or similar isolation orders; (ii) decline in consumers' desire for in-person interactions and physical home tours; and (iii) deteriorating economic conditions, such as increased unemployment rates, recessionary conditions, lower yields on individuals' investment portfolios, and more stringent mortgage financing conditions . In addition, we have considered the impacts and uncertainties of COVID-19 in our use of estimates in preparation of our consolidated financial statements. These estimates include, but are not limited to, likelihood of achieving performance conditions under performance-based equity awards, net realizable value of inventory, and the fair value of reporting units and goodwill for impairment. Use of Estimates — The preparation of consolidated financial statements, in conformity with GAAP, requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and results of operations during the respective periods. We evaluate our estimates on an ongoing basis. In January 2020 we adopted ASU 2016-13, Financial Instruments—Credit Losses (Topic 326), which modifies the measurement of credit losses on financial instruments. As part of the adoption we estimated the current expected credit losses for certain classes of relevant assets. The amounts realized from the affected assets will depend on, among other factors, general business conditions, including the impacts from COVID-19, and could differ in the near term from carrying amounts reflected in the consolidated financial statements. Further description of the impact of this pronouncement is included in Recently Adopted Accounting Pronouncements. Accounts Receivable and Allowance for Credit Losses —We have two material classes of receivables: (i) real estate services receivables and (ii) receivables from the sale of homes. Accounts receivable related to these classes represent closed transactions for which cash has not yet been received. We establish an allowance for expected credit losses based on historical experience of collectibility, current external economic conditions that may affect collectibility, and current or expected changes to the regulatory environment in which we operate our real estate services business. As the majority of our transactions are processed through escrow, collectibility is not a significant risk, and we have determined the nature of our receivables to have similar credit quality indicators. We evaluate for changes in credit quality indicators on an annual basis or in the event of a material economic event or material change in the regulatory environment in which we operate, with the most recent assessment being performed in March 2020. Investments —We have two types of investments: (i) available-for-sale investments that are available to support our operational needs, which are reported on the balance sheets as short-term and long-term investments, and (ii) long-term equity investments accounted for under the cost method, which are reported in other non-current assets. Available-for-sale Our short-term and long-term investments consist primarily of U.S. treasury securities and other federal or local government issued securities, all of which are classified as available-for-sale. Available-for-sale debt securities are recorded at fair value, and unrealized holding gains and losses are recorded as a component of accumulated other comprehensive income. Available-for-sale securities with maturities of one year or less and those identified by management at the time of purchase to be used to fund operations within one year are classified as short-term. All other available-for-sale securities are classified as long-term. We evaluate our available-for-sale securities, both ones classified as cash equivalents and as investments, for expected credit losses on a quarterly basis. An expected credit loss reserve is charged against the fair value of an available-for-sale debt security when it is identified, with a credit loss charged against net earnings. We review factors to determine whether an expected credit loss exists based on credit quality indicators, such as the extent to which the fair value as of the reporting date is less than the amortized cost basis, present value of cash flows expected to be collected, the financial condition and prospects of the issuer, adverse conditions specifically related to the security and any changes to the credit rating of the security by a rating agency. Realized gains and losses are accounted for using the specific identification method. Purchases and sales are recorded on a trade date basis. Cost Method Investments In December 2018, we purchased an equity interest in a privately held company for approximately $2,000 , which is classified as long-term. The investment is an equity security without a readily determinable fair value that is accounted for at cost minus any impairment, plus or minus changes resulting from observable price changes in orderly transactions for identical or similar investments of the same issuer. We perform a qualitative assessment considering impairment indicators to evaluate whether the investment is impaired as of the end of each reporting period. See Note 3 for information on our assessment. Advertising and Advertising Production Costs —We expense advertising costs as they are incurred and production costs as of the first date the advertisement takes place. Advertising costs totaled $22,529 and $30,234 for the three months ended March 31, 2020 and 2019 , respectively, and are included in marketing expenses. Advertising production costs totaled $174 and $48 for the three months ended March 31, 2020 and 2019 , respectively, and are included in marketing expenses. Recently Adopted Accounting Pronouncements — In January 2020, we adopted ASU 2016-13, Financial Instruments—Credit Losses (Topic 326), using a modified-retrospective approach. The adoption of this guidance requires a cumulative-effect adjustment to retained earnings as of the beginning of the first reporting period in which the guidance is effective. The pronouncement, along with the related subsequent pronouncements that include clarifications, modifies the measurement of credit losses on financial instruments. This guidance requires the use of an expected loss impairment model for instruments measured at amortized cost based on relevant information about past events, including historical experience, current conditions, and reasonable and supportable forecasts that affect the collectibility of the reported amount. The adoption of this pronouncement did not have a material impact on our consolidated financial statements. See specific accounting policies for accounts receivable and available-for-sale debt securities previously discussed in this Note 1, and see Note 2 and Note 3 for additional impacts from the adoption. Recently Issued Accounting Pronouncements — Recent accounting pronouncements issued by the Financial Accounting Standards Board (including its Emerging Issues Task Force), the American Institute of Certified Public Accountants, and the Securities and Exchange Commission did not have, or are not expected to have, a material impact on our present or future consolidated financial statements.

Segment Reporting and Revenue

Segment Reporting and Revenue	3 Months Ended
	Mar. 31, 2020
Segment Reporting [Abstract]
Segment Reporting and Revenue	Segment Reporting and Revenue In operation of the business, our management, including our chief operating decision maker, 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, all of which are located in the United States. All other financial information is presented on a consolidated basis. We have five operating segments and two reportable segments, real estate services and properties. We generate revenue primarily from commissions and fees charged on real estate services transactions closed by our lead agents or partner agents, and from the sale of homes . Our key revenue components are brokerage revenue, partner revenue, properties revenue, and other revenue. Information on each of the reportable and other segments and reconciliation to consolidated net loss is as follows: Three Months Ended March 31, 2020 2019 Real estate services Brokerage revenue $ 102,351 $ 81,314 Partner revenue 6,285 4,576 Total real estate services revenue 108,636 85,890 Cost of revenue 93,562 80,784 Gross profit 15,074 5,106 Properties Revenue 79,098 21,373 Cost of revenue 79,299 22,993 Gross profit (201 ) (1,620 ) Other Revenue 4,250 3,047 Cost of revenue 6,244 3,780 Gross profit (1,994 ) (733 ) Intercompany eliminations Revenue (989 ) (169 ) Cost of revenue (989 ) $ (169 ) Gross profit — — Consolidated Revenue 190,995 110,141 Cost of revenue 178,116 107,388 Gross profit 12,879 2,753 Operating expenses 70,309 70,205 Interest income 1,103 2,316 Interest expense (2,444 ) (2,136 ) Other income (expense), net (1,346 ) 92 Net loss $ (60,117 ) $ (67,180 ) Revenue earned but not received is recorded as accounts receivable on our consolidated balance sheets, net of an allowance for expected credit losses. Accounts receivable consists primarily of commission revenue and proceeds from the sale of homes in-transit through the escrow process, and therefore it is not estimated. Based on the regulated environment in which we operate and the nature of our receivables, we do not expect material credit losses, and write-offs were immaterial in the periods presented.

Financial Instruments

Financial Instruments	3 Months Ended
	Mar. 31, 2020
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. 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. 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. Notional Amounts March 31, 2020 December 31, 2019 Interest rate lock commitments $ 73,382 $ 37,453 Forward sales commitments 66,448 39,447 The locations and amounts of gains (losses) recognized in income related to our derivatives are as follows: March 31, Instrument Classification 2020 2019 Interest rate lock commitments Service revenue $ 1,195 $ 446 Forward sales commitments Service revenue (1,571 ) (244 ) Fair Value of Financial Instruments 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 March 31, 2020 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 $ 194,530 $ 194,530 $ — $ — Short-term investments U.S. treasury securities 75,049 75,049 — — Loans held for sale 44,321 — 44,321 — Prepaid expenses and other current assets Interest rate lock commitments 1,825 — — 1,825 Forward sales commitments 200 — 200 — Total prepaid expenses and other current assets 2,025 — 200 1,825 Long-term investments U.S. treasury securities 24,717 24,717 — — Agency bonds 1,994 1,994 — — Total long-term investments 26,711 26,711 — — Total assets $ 342,636 $ 296,290 $ 44,521 $ 1,825 Liabilities Accrued liabilities Interest rate lock commitments $ 200 $ — $ — $ 200 Forward sales commitments 1,816 — 1,816 — Total liabilities $ 2,016 $ — $ 1,816 $ 200 Balance at December 31, 2019 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 $ 221,442 $ 221,442 $ — $ — Short-term investments U.S. treasury securities 70,029 70,029 — — Loans held for sale 21,985 — 21,985 — Prepaid expenses and other current assets Interest rate lock commitments 496 — — 496 Forward sales commitments 4 — 4 — Total prepaid expenses and other current assets 500 — 4 496 Long-term investments U.S. treasury securities 30,978 30,978 — — Total assets $ 344,934 $ 322,449 $ 21,989 $ 496 Liabilities Accrued liabilities Interest rate lock commitments $ 58 $ — $ — $ 58 Forward sales commitments 57 — 57 — Total liabilities $ 115 $ — $ 57 $ 58 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 following is a quantitative summary of key unobservable inputs used in the valuation of IRLCs: Key Inputs Valuation Technique March 31, 2020 December 31, 2019 Weighted-average pull-through rate Market pricing 75.1% 78.2% The following is a summary of changes in the fair value of IRLCs for the period ended March 31, 2020: Balance, net—December 31, 2019 $ 430 Issuances of interest rate lock commitments 3,318 Settlements of interest rate lock commitments (2,494 ) Net gain recognized in earnings 371 Balance, net—March 31, 2020 $ 1,625 Changes in fair value recognized during the period relating to assets still held at March 31, 2020 $ 1,195 There were no transfers into or out of Level 3 financial instruments during the period. See Note 14 for the carrying amount and estimated fair value of our convertible senior notes. 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, cost method investments, and other assets. These assets are measured at fair value if determined to be impaired. During the period ended March 31, 2020 , we determined that the fair value of our cost method investment in a privately-held company was less than the carrying value of $2,000 based on a variety of impairment indicators including the historical performance and future prospects of the company; therefore, we recognized a non-cash impairment charge of $1,420 related to this investment. The impairment charge is included in Impairment costs within our consolidated statement of cash flows and is included in Other income (expense), net within our consolidated statements of operations. We did not record any other significant nonrecurring fair value measurements after initial recognition for the period ended March 31, 2020 . The following table summarizes the cost or amortized cost, gross unrealized gains and losses, and estimated fair market value of our cash, money market funds, restricted cash, and available-for-sale investments. March 31, 2020 Fair Value Hierarchy Cost or Amortized Cost Unrealized Gains Unrealized Losses Estimated Fair Value Short-term Investments Long-term Investments Cash N/A $ 18,831 $ — $ — $ 18,831 $ — $ — Money markets funds Level 1 194,530 — — 194,530 — — Restricted cash N/A 16,772 — — 16,772 — — U.S. treasury securities Level 1 99,192 574 — 99,766 75,049 24,717 Agency bonds Level 1 2,000 — (6 ) 1,994 — 1,994 Total $ 331,325 $ 574 $ (6 ) $ 331,893 $ 75,049 $ 26,711 December 31, 2019 Fair Value Hierarchy Cost or Amortized Cost Unrealized Gains Unrealized Losses Estimated Fair Value Short-term Investments Long-term Investments Cash N/A $ 13,237 $ — $ — $ 13,237 $ — $ — Money markets funds Level 1 221,442 — — 221,442 — — Restricted cash N/A 12,769 — — 12,769 — — U.S. treasury securities Level 1 100,998 31 (22 ) 101,007 70,029 30,978 Total $ 348,446 $ 31 $ (22 ) $ 348,455 $ 70,029 $ 30,978 As of March 31, 2020 and December 31, 2019 , the aggregate fair value of available-for-sale debt securities in an unrealized loss position totaled $2,094 and $46,550 , with aggregate unrealized losses of $6 and $22 , respectively. 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. treasury securities, all with high quality credit ratings issued by various credit agencies. As of March 31, 2020 and December 31, 2019 , we had accrued interest of $164 and $183 , 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	3 Months Ended
	Mar. 31, 2020
Inventory Disclosure [Abstract]
Inventory	Inventory The following is a summary of inventory as of the dates presented: March 31, 2020 December 31, 2019 Homes for sale $ 47,887 $ 36,982 Homes not available for sale 3,667 3,163 Homes under improvement 19,095 34,445 Inventory $ 70,649 $ 74,590 Inventory costs include direct home acquisition costs and any capitalized improvements, net of lower of cost or net realizable value write-downs applied on a specific home basis. As of March 31, 2020 and December 31, 2019 , lower of cost or net realizable value write-downs were $818 and $143 , respectively. The following is the inventory activity for the three months ended March 31, 2020 : Inventory as of January 1, 2020 $ 74,590 Purchases and capitalized improvements to inventory 68,384 Relief of inventory to cost of revenue (71,650 ) Lower of cost or net realizable value write-downs, net (675 ) Inventory as of March 31, 2020 $ 70,649

Property and Equipment

Property and Equipment	3 Months Ended
	Mar. 31, 2020
Property, Plant and Equipment [Abstract]
Property and Equipment	Property and Equipment The following is a summary of property and equipment as of the dates presented: Useful Lives (Years) March 31, 2020 December 31, 2019 Leasehold improvements Shorter of lease term or economic life $ 28,178 $ 28,141 Website and software development costs 2-3 30,141 27,602 Computer and office equipment 3 5,627 4,846 Software 3 1,126 595 Furniture 7 7,083 6,965 Construction in progress N/A 428 475 Property and equipment, gross 72,583 68,624 Accumulated depreciation and amortization (32,087 ) (29,047 ) Property and equipment, net $ 40,496 $ 39,577 Depreciation and amortization expense for property and equipment amounted to $3,186 and $1,515 for the three months ended March 31, 2020 and 2019 , respectively. We capitalized software development costs, including stock-based compensation, of $2,677 and $1,911 during the three months ended March 31, 2020 and 2019 , respectively.

Leases

Leases	3 Months Ended
	Mar. 31, 2020
Leases [Abstract]
Leases	Leases The following are the components of lease activity as of the dates presented: Three Months Ended March 31, Lease Cost Classification 2020 2019 Operating lease cost: Operating lease cost (1) Cost of revenue $ 2,138 $ 1,693 Operating lease cost (1) Operating expenses 1,094 855 Total operating lease cost $ 3,232 $ 2,548 Finance lease cost: Amortization of right-of-use assets Cost of revenue $ 17 $ — Interest on lease liabilities Cost of revenue 3 — Total finance lease cost $ 20 $ — (1) Includes lease expense with initial terms of twelve months or less of $226 and $821 for the three months ended March 31, 2020 and March 31, 2019 , respectively. Maturity of Lease Liabilities Operating Leases Finance Leases 2020, excluding the three months ended March 31, 2020 11,461 45 2021 14,289 60 2022 13,589 60 2023 12,612 46 2024 10,931 — Thereafter 16,915 — Total lease payments $ 79,797 $ 211 Less: Interest and other (1) 11,203 18 Present value of lease liabilities $ 68,594 $ 193 (1) Interest and other consists of interest expense related to capitalized right of use operating lease liabilities of $9,402 , interest expense related to capitalized right of use financing lease liabilities of $18 , commitments related to operating leases that have not yet commenced, and operating leases with initial terms of twelve months or less. There were no leases entered into during the three months ended March 31, 2020 that provided a readily determinable implicit rate; therefore, we used our estimated incremental borrowing rate for each type of lease to discount the lease payments based on information available at lease commencement. Additionally, we evaluated the performance of existing leases in relation to our leasing strategy and have determined that most renewal options would not be reasonably certain to be exercised. Lease Term and Discount Rate March 31, 2020 December 31, 2019 Weighted average remaining operating lease term (years) 5.9 6.1 Weighted average remaining finance lease term (years) 3.5 3.8 Weighted average discount rate for operating leases 4.4 % 4.4 % Weighted average discount rate for finance leases 5.4 % 5.4 % Three Months Ended March 31, Supplemental Cash Flow Information 2020 2019 Cash paid for amounts included in the measurement of lease liabilities Operating cash flows from operating leases $ 3,464 $ 1,975 Operating cash flows from finance leases 3 — Financing cash flows from finance leases 12 — Right of use assets obtained in exchange for lease liabilities Operating leases $ 223 $ 33,953 Finance leases — —

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Legal Proceedings — On August 28, 2019, one of our former independent contractor licensed sales associates filed a complaint against us in the Superior Court of California, County of San Francisco alleging that we misclassified her as an independent contractor instead of an employee. Given the preliminary stage of this case and the claims and issues presented, we cannot estimate a range of reasonably possible losses. In addition to the matter discussed above, from time to time, we are involved in litigation, claims, and other proceedings arising in the ordinary course of our business. Except for the matter discussed above, we do not believe that any of the pending litigation, claims, and other proceedings are material to our business. Leases and Other Commitments —We lease office space under noncancelable operating leases with terms ranging from one to 11 years and vehicles under noncancelable finance leases with terms of four years . Generally, the operating leases require a fixed minimum rent with contractual minimum rent increases over the lease term. Other commitments relate to homes that are under contract to purchase through our properties business but that have not closed, and network infrastructure for our data operations. The following are future minimum payments due under these agreements as of March 31, 2020 : Leases Other Commitments 2020, excluding the three months ended March 31, 2020 $ 11,506 $ 8,716 2021 14,349 4,780 2022 13,649 5,439 2023 12,658 — 2024 and thereafter 27,846 — Total future minimum payments $ 80,008 $ 18,935

Acquired Intangible Assets

Acquired Intangible Assets	3 Months Ended
	Mar. 31, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Acquired Intangible Assets	Acquired Intangible Assets The following are the details of our intangible assets subject to amortization as of the dates presented: March 31, 2020 December 31, 2019 Useful Lives (Years) Gross Accumulated Amortization Net Gross Accumulated Amortization Net Trade names 10 $ 1,040 $ (572 ) $ 468 $ 1,040 $ (546 ) $ 494 Developed technology 10 2,980 (1,639 ) 1,341 2,980 (1,564 ) 1,416 Customer relationships 10 860 (473 ) 387 860 (452 ) 408 $ 4,880 $ (2,684 ) $ 2,196 $ 4,880 $ (2,562 ) $ 2,318 Acquired intangible assets are amortized using the straight-line method over their estimated useful life, which approximates the expected use of these assets. Amortization expense amounted to $122 for each of the three months ended March 31, 2020 and 2019 . We will recognize the remaining amortization expense of $2,196 over a five-year period, with the first four years recognizing expense of $488 per year and the fifth year recognizing expense of $244 .

Accrued Liabilities

Accrued Liabilities	3 Months Ended
	Mar. 31, 2020
Payables and Accruals [Abstract]
Accrued Liabilities	Accrued Liabilities The following are details of accrued liabilities as of the dates presented: March 31, 2020 December 31, 2019 Accrued compensation and benefits $ 37,300 $ 30,462 Miscellaneous accrued liabilities 21,156 7,560 Total accrued liabilities $ 58,456 $ 38,022 The increase in miscellaneous accrued liabilities since December 31, 2019 was driven primarily by an increase in marketing activity during the quarter ended March 31, 2020, which was a result of increased marketing spend and timing of those expenses.

Other Payables

Other Payables	3 Months Ended
	Mar. 31, 2020
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 following are details of other payables as of the dates presented: March 31, 2020 December 31, 2019 Customer deposits $ 10,793 $ 7,109 Miscellaneous payables 924 775 Total other payables $ 11,717 $ 7,884

Equity and Equity Compensation

Equity and Equity Compensation Plans	3 Months Ended
	Mar. 31, 2020
Share-based Payment Arrangement [Abstract]
Equity and Equity Compensation Plans	Equity and Equity Compensation Plans Common Stock —As of March 31, 2020 and December 31, 2019 , 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 March 31, 2020 and December 31, 2019 , 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 , of which no shares were issued or outstanding. Amended and Restated 2004 Equity Incentive Plan — We granted options under our 2004 Equity Incentive Plan, as amended ("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 ("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, officers, 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 the 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 over a four -year period We have reserved shares of common stock for future issuance under our 2017 EIP as follows: March 31, 2020 December 31, 2019 Stock options issued and outstanding 7,028,719 7,792,181 Restricted stock units issued and outstanding 4,681,875 5,023,412 Shares available for future equity grants 11,899,400 7,100,499 Total shares reserved for future issuance 23,609,994 19,916,092 2017 Employee Stock Purchase Plan — Our 2017 Employee Stock Purchase Plan ("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: Three Months Ended March 31, 2020 Year Ended December 31, 2019 Shares available for issuance at beginning of period 3,330,271 2,890,973 Shares issued during the period — 490,717 Total shares available for future issuance at end of period 3,330,271 2,400,256 Stock Options —The following table summarizes activity for stock options for the three months ended March 31, 2020 : Number of Options Weighted- Average Exercise Price Weighted-Average Remaining Contractual Life (Years) Aggregate Intrinsic Value Outstanding as of January 1, 2020 7,792,181 $ 7.00 5.28 $ 111,122 Options exercised (738,398) 5.30 Options forfeited (20,798) 9.01 Options canceled (4,266) 10.80 Outstanding as of March 31, 2020 7,028,719 $ 7.17 5.12 $ 59,786 Options exercisable as of March 31, 2020 6,472,555 $ 6.54 4.93 $ 57,443 The grant date fair value of options to purchase common stock is recorded as stock-based compensation over the vesting period. As of March 31, 2020 , there was $2,255 of total unrecognized compensation cost related to stock options. These costs are expected to be recognized over a weighted-average period of 1.01 years . The total fair value of stock options vested during the three months ended March 31, 2020 and 2019 was $739 and $1,449 , respectively. The total intrinsic value of stock options exercised during the three months ended March 31, 2020 and 2019 was $15,251 and $8,682 , respectively. On June 1, 2019, we granted stock options subject to performance conditions, with a target of 150,000 shares and a maximum 300,000 shares, to 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 (the "2019 PSUs"). None of the options vested in the three months ended March 31, 2020 . Restricted Stock Units —The following table summarizes activity for restricted stock units for the three months ended March 31, 2020 : Restricted Stock Units Weighted Average Grant-Date Fair Value Outstanding as of January 1, 2020 5,023,412 $ 18.69 Granted 141,413 27.06 Vested (320,440 ) 19.36 Forfeited or canceled (162,510 ) 19.29 Outstanding as of March 31, 2020 4,681,875 $ 18.87 The grant date fair value of restricted stock units is recorded as stock-based compensation over the vesting period. As of March 31, 2020 , there was $77,435 of total unrecognized compensation cost related to restricted stock units, which is expected to be recognized over a weighted-average period of 2.86 years years. As of March 31, 2020 , there were outstanding 314,999 restricted stock units subject to performance conditions (the "PSUs") at 100% of the target level. Depending on our achievement of the performance 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 award will vest, subject to the recipient 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 conditions. Stock-based compensation expense for PSUs will be recognized when it is probable that the performance conditions will be achieved. During the three months ended March 31, 2020 , we recognized $(464) , which includes (i) an adjustment of $(617) for the reversal of expense from the year ended December 31, 2019 related to the 2019 PSUs as the probability of achieving the performance conditions was adjusted downward and (ii) a charge of $153 related to the 2019 PSUs expense for the three months ended March 31, 2020 . For the three months ended March 31, 2019, we recognized $278 for share-based compensation expense related to the PSUs we granted during 2018, which was later reversed as the probability of achieving the performance conditions was determined to be not probable. Compensation Cost —The following table details, for each period indicated, (i) our stock-based compensation, net of forfeitures, and the amount capitalized in internally developed software and (ii) changes to the probability of achieving outstanding performance-based equity awards, each as included in our consolidated statements of operations: Three Months Ended March 31, 2020 2019 Cost of revenue $ 1,638 $ 1,465 Technology and development 3,648 2,656 Marketing 375 286 General and administrative 1,550 1,999 Total stock-based compensation $ 7,211 $ 6,406 We capitalize stock-based compensation related to work performed on internally developed software. There was $504 and $270 of stock-based compensation that was capitalized in the three months ended March 31, 2020 and 2019 , respectively. All capitalized stock-based compensation is related to employees in technology and development.

Net Loss per Share Attributable

Net Loss per Share Attributable to Common Stock	3 Months Ended
	Mar. 31, 2020
Earnings Per Share [Abstract]
Net Loss per Share Attributable to Common Stock	Net Loss per Share Attributable to Common Stock Net loss per share attributable to common stock is computed by dividing the net loss 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, and convertible senior notes, which are considered in the calculation of diluted net income per share whenever doing so would be dilutive. The following table sets forth the calculation of basic and diluted net loss per share attributable to common stock during the periods presented: Three Months Ended March 31, 2020 2019 Numerator: Net loss attributable to common stock—basic and diluted $ (60,117 ) $ (67,180 ) Denominator: Weighted average shares—basic and diluted 93,442,706 90,610,416 Net loss per share: Net loss per share attributable to common stock—basic and diluted $ (0.64 ) $ (0.74 ) The following outstanding shares of common stock equivalents as of March 31, 2020 and 2019 were excluded from the computation of the diluted net loss per share for the periods presented because their effect would have been anti-dilutive: Three Months Ended March 31, 2020 2019 Stock options outstanding 7,028,719 8,713,162 Restricted stock units outstanding 4,681,875 3,588,275 Employee stock purchase plan 233,416 290,647 Total 11,944,010 12,592,084 We are required to consider the impact of our convertible senior notes on our diluted net income per share based on the treasury stock method as we have the ability, and intent, to settle any conversions of the notes solely in cash. The treasury stock method requires that the dilutive effect of common stock issuable upon conversion of the notes be computed in the periods in which we report net income. For the three months ended March 31, 2020 there was no dilutive impact from the notes.

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2020
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes Our effective tax rate for the three months ended March 31, 2020 and 2019 was 0% as a result of our recording a full valuation allowance against the 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 three months ended March 31, 2020 and 2019 . 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 there was an ownership change in 2006 and $1,538 of the 2006 net operating loss is unavailable. As of December 31, 2019 , we had accumulated approximately $195,133 of federal tax losses and approximately $10,421 (tax effected) of state tax losses. Federal net operating losses are available to offset federal taxable income and begin to expire in 2025. Federal net operating loss carryforwards of $109,484 generated during 2018 and 2019 are available to offset future U.S. federal taxable income over an indefinite period. Our material income tax jurisdiction is the United States (federal). As a result of NOL carryforwards, we are subject to audit for all tax years for federal purposes. All tax years remain subject to examination in various other jurisdictions that are not material to our consolidated financial statements.

Debt

Debt	3 Months Ended
	Mar. 31, 2020
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 related to the loans. The following table summarizes borrowings under these facilities as of the periods presented: Lender Borrowing Capacity as of March 31, 2020 Borrowings as of March 31, 2020 Borrowings as of December 31, 2019 Western Alliance Bank $ 24,500 $ 13,613 $ 8,489 Texas Capital Bank, N.A. 24,500 17,552 10,210 Flagstar Bank 20,000 11,421 2,603 Total $ 69,000 $ 42,586 $ 21,302 Borrowings under the facility with Western Alliance Bank ("Western Alliance") mature on June 15, 2020 and generally bear interest at a rate equal to the greater of (i) one-month LIBOR plus 2.00% or (ii) 3.50% . The weighted average interest rate on outstanding borrowings as of March 31, 2020 and December 31, 2019 was 3.52% and 3.79% , respectively. The agreement governing the facility requires Redfin Mortgage to maintain certain financial covenants. Additionally, Redfin Corporation has agreed to make capital contributions in an amount necessary for Redfin Mortgage to satisfy its adjusted tangible net worth financial covenant under the agreement. Redfin Mortgage is in default of this facility because it failed to satisfy a financial covenant as of March 31, 2020 , but Western Alliance has not enforced its remedy under the agreement of requiring Redfin Mortgage to repurchase all outstanding loans held by the lender. Borrowings under the facility with Texas Capital Bank, N.A. ("Texas Capital") mature on May 6, 2020 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 0.50% or (ii) 3.50% . The weighted average interest rate on outstanding borrowings as of March 31, 2020 and December 31, 2019 was 3.50% and 3.51% , respectively. The agreement governing the facility requires Redfin Mortgage to maintain certain financial covenants. Additionally, Redfin Corporation has guaranteed Redfin Mortgage’s obligations under the agreement. Redfin Mortgage is in default of this facility because it failed to satisfy a financial covenant as of March 31, 2020 , but Texas Capital has not enforced its remedies under the agreement of (i) requiring Redfin Mortgage to repurchase Texas Capital's interest in all outstanding loans subject to the agreement or (ii) selling all outstanding loans subject to 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% . The weighted average interest rate on outstanding borrowings as of March 31, 2020 and December 31, 2019 was 3.36% and 3.69% , respectively. 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. 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. 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: Lender Borrowing Capacity as of March 31, 2020 Borrowings as of Borrowings as of December 31, 2019 Goldman Sachs Bank USA $ 100,000 $ 8,901 $ 4,444 The facility matures on January 26, 2021, 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. Borrowings under the facility prior to March 24, 2020 generally bore interest at a rate of one-month LIBOR (subject to a floor of 0.50% ) plus 2.65% . For borrowings under the facility on and after March 24, 2020, each new borrowing generally bears 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. The weighted average interest rate on outstanding borrowings as of March 31, 2020 and December 31, 2019 was 3.77% and 4.45% , respectively. 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 March 31, 2020 , RedfinNow Borrower had $53,445 of total assets, of which $44,455 related to inventory and $5,648 in cash and cash equivalents. As of December 31, 2019 , RedfinNow Borrower had $16,200 of total assets, of which $7,456 related to inventory and $5,663 in cash and equivalents. For the three months ended March 31, 2020 , we amortized $154 of the debt issuance costs and recognized $80 of interest expense. Convertible Senior Notes — On July 23, 2018, we issued $143,750 aggregate principal amount of convertible senior notes. The notes are senior, unsecured obligations of Redfin Corporation, and bear interest at a fixed rate of 1.75% per year, payable semi-annually in arrears on January 15 and July 15. The effective interest rate of the liability portion of the debt is 7.25% . The notes mature on July 15, 2023, unless earlier repurchased, redeemed or converted. As of March 31, 2020 , no conversion events have occurred. We will settle conversions of the 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 have the ability, and intend, to settle any conversions solely in cash. The following details the carrying value of the convertible senior notes as of the dates presented: March 31, 2020 December 31, 2019 Principal $ 143,750 $ 143,750 Less: debt discount, net of amortization (19,840 ) (21,231 ) Less: debt issuance costs, net of amortization (2,618 ) (2,803 ) Net carrying amount of the convertible senior notes $ 121,292 $ 119,716 The total estimated fair value of the convertible senior notes as of March 31, 2020 and December 31, 2019 was approximately $130,801 and $142,672 , respectively, based on the closing trading price of the notes on last day of trading for the period. The fair value has been classified as Level 2 within the fair value hierarchy given the limited trading activity of the notes. The following table sets forth total interest expense recognized related to the convertible senior notes for the periods presented: Three Months Ended March 31, 2020 2019 Amortization of debt discount $ 1,390 $ 1,329 Amortization of debt issuance costs 186 178 Total amortization of debt issuance costs and accretion of equity portion 1,576 1,507 Contractual interest expense 629 629 Total interest expense related to the notes $ 2,205 $ 2,136

Subsequent Events

Subsequent Events	3 Months Ended
	Mar. 31, 2020
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events Private Placement — 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, which we refer to as our convertible preferred stock. Workforce Reduction — In April 2020, we reduced our number of employees by approximately 400 people, which represented approximately ten percent of our employees. As a result of this workforce reduction, we incurred a pre-tax charge for one-time termination costs, which consisted of severance and related costs, of $4,400 in April 2020. We additionally placed approximately 1,000 employees on furlough, of which approximately 135 were invited to return in early May. As of the effective date of any furlough, we provided transition pay to each employee, resulting in a pre-tax charge of approximately $1,000 . In addition, for any furloughed employee enrolled in our health-care benefit plans, we will continue to provide benefits through the duration of the furlough. Flagstar Warehouse Credit Facility — On April 20, 2020, Redfin Mortgage temporarily increased the borrowing capacity under its warehouse credit facility with Flagstar to $24,500 through May 31, 2020. Texas Capital Warehouse Credit Facility —On May 4, 2020, Redfin Mortgage extended the expiration date of its warehouse credit facility with Texas Capital to June 5, 2020 .

Summary of Accounting Policies

Summary of Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2020
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, 2019 that is included in this quarterly report is derived from the audited consolidated financial statements and notes for the year ended December 31, 2019 included in Item 8 in our annual report for the year ended December 31, 2019 . 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 March 31, 2020 , the statements of comprehensive loss and stockholders' equity for the three months ended March 31, 2020 and 2019 , and the statement of cash flows for the three months ended March 31, 2020 and 2019 . The results for the three months ended March 31, 2020 are not necessarily indicative of the results to be expected for the year ending December 31, 2020 or for any interim period or for any other future year.
Principles of Consolidation	Principles of Consolidation —The unaudited consolidated interim financial statements include the accounts of Redfin 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 management to make estimates and assumptions that affect the reported amounts of assets and liabilities and results of operations during the respective periods. We evaluate our estimates on an ongoing basis. In January 2020 we adopted ASU 2016-13, Financial Instruments—Credit Losses (Topic 326), which modifies the measurement of credit losses on financial instruments. As part of the adoption we estimated the current expected credit losses for certain classes of relevant assets. The amounts realized from the affected assets will depend on, among other factors, general business conditions, including the impacts from COVID-19, and could differ in the near term from carrying amounts reflected in the consolidated financial statements. Further description of the impact of this pronouncement is included in Recently Adopted Accounting Pronouncements.
Accounts Receivable and Allowance for Credit Losses	Accounts Receivable and Allowance for Credit Losses —We have two material classes of receivables: (i) real estate services receivables and (ii) receivables from the sale of homes. Accounts receivable related to these classes represent closed transactions for which cash has not yet been received. We establish an allowance for expected credit losses based on historical experience of collectibility, current external economic conditions that may affect collectibility, and current or expected changes to the regulatory environment in which we operate our real estate services business. As the majority of our transactions are processed through escrow, collectibility is not a significant risk, and we have determined the nature of our receivables to have similar credit quality indicators. We evaluate for changes in credit quality indicators on an annual basis or in the event of a material economic event or material change in the regulatory environment in which we operate, with the most recent assessment being performed in March 2020.
Investments	Investments —We have two types of investments: (i) available-for-sale investments that are available to support our operational needs, which are reported on the balance sheets as short-term and long-term investments, and (ii) long-term equity investments accounted for under the cost method, which are reported in other non-current assets. Available-for-sale Our short-term and long-term investments consist primarily of U.S. treasury securities and other federal or local government issued securities, all of which are classified as available-for-sale. Available-for-sale debt securities are recorded at fair value, and unrealized holding gains and losses are recorded as a component of accumulated other comprehensive income. Available-for-sale securities with maturities of one year or less and those identified by management at the time of purchase to be used to fund operations within one year are classified as short-term. All other available-for-sale securities are classified as long-term. We evaluate our available-for-sale securities, both ones classified as cash equivalents and as investments, for expected credit losses on a quarterly basis. An expected credit loss reserve is charged against the fair value of an available-for-sale debt security when it is identified, with a credit loss charged against net earnings. We review factors to determine whether an expected credit loss exists based on credit quality indicators, such as the extent to which the fair value as of the reporting date is less than the amortized cost basis, present value of cash flows expected to be collected, the financial condition and prospects of the issuer, adverse conditions specifically related to the security and any changes to the credit rating of the security by a rating agency. Realized gains and losses are accounted for using the specific identification method. Purchases and sales are recorded on a trade date basis. Cost Method Investments In December 2018, we purchased an equity interest in a privately held company for approximately $2,000
Advertising and Advertising Production Costs	Advertising and Advertising Production Costs
Recently Adopted and Issued Accounting Pronouncements	Recently Adopted Accounting Pronouncements — In January 2020, we adopted ASU 2016-13, Financial Instruments—Credit Losses (Topic 326), using a modified-retrospective approach. The adoption of this guidance requires a cumulative-effect adjustment to retained earnings as of the beginning of the first reporting period in which the guidance is effective. The pronouncement, along with the related subsequent pronouncements that include clarifications, modifies the measurement of credit losses on financial instruments. This guidance requires the use of an expected loss impairment model for instruments measured at amortized cost based on relevant information about past events, including historical experience, current conditions, and reasonable and supportable forecasts that affect the collectibility of the reported amount. The adoption of this pronouncement did not have a material impact on our consolidated financial statements. See specific accounting policies for accounts receivable and available-for-sale debt securities previously discussed in this Note 1, and see Note 2 and Note 3 for additional impacts from the adoption. Recently Issued Accounting Pronouncements — Recent accounting pronouncements issued by the Financial Accounting Standards Board (including its Emerging Issues Task Force), the American Institute of Certified Public Accountants, and the Securities and Exchange Commission did not have, or are not expected to have, a material impact on our present or future consolidated financial statements.

Segment Reporting and Revenue (

Segment Reporting and Revenue (Tables)	3 Months Ended
	Mar. 31, 2020
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 is as follows: Three Months Ended March 31, 2020 2019 Real estate services Brokerage revenue $ 102,351 $ 81,314 Partner revenue 6,285 4,576 Total real estate services revenue 108,636 85,890 Cost of revenue 93,562 80,784 Gross profit 15,074 5,106 Properties Revenue 79,098 21,373 Cost of revenue 79,299 22,993 Gross profit (201 ) (1,620 ) Other Revenue 4,250 3,047 Cost of revenue 6,244 3,780 Gross profit (1,994 ) (733 ) Intercompany eliminations Revenue (989 ) (169 ) Cost of revenue (989 ) $ (169 ) Gross profit — — Consolidated Revenue 190,995 110,141 Cost of revenue 178,116 107,388 Gross profit 12,879 2,753 Operating expenses 70,309 70,205 Interest income 1,103 2,316 Interest expense (2,444 ) (2,136 ) Other income (expense), net (1,346 ) 92 Net loss $ (60,117 ) $ (67,180 )

Financial Instruments (Tables)

Financial Instruments (Tables)	3 Months Ended
	Mar. 31, 2020
Fair Value Disclosures [Abstract]
Schedule of Notional Amounts of Outstanding Derivative Positions	Notional Amounts March 31, 2020 December 31, 2019 Interest rate lock commitments $ 73,382 $ 37,453 Forward sales commitments 66,448 39,447
Derivative Instruments, Gain (Loss)	The locations and amounts of gains (losses) recognized in income related to our derivatives are as follows: March 31, Instrument Classification 2020 2019 Interest rate lock commitments Service revenue $ 1,195 $ 446 Forward sales commitments Service revenue (1,571 ) (244 )
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 March 31, 2020 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 $ 194,530 $ 194,530 $ — $ — Short-term investments U.S. treasury securities 75,049 75,049 — — Loans held for sale 44,321 — 44,321 — Prepaid expenses and other current assets Interest rate lock commitments 1,825 — — 1,825 Forward sales commitments 200 — 200 — Total prepaid expenses and other current assets 2,025 — 200 1,825 Long-term investments U.S. treasury securities 24,717 24,717 — — Agency bonds 1,994 1,994 — — Total long-term investments 26,711 26,711 — — Total assets $ 342,636 $ 296,290 $ 44,521 $ 1,825 Liabilities Accrued liabilities Interest rate lock commitments $ 200 $ — $ — $ 200 Forward sales commitments 1,816 — 1,816 — Total liabilities $ 2,016 $ — $ 1,816 $ 200 Balance at December 31, 2019 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 $ 221,442 $ 221,442 $ — $ — Short-term investments U.S. treasury securities 70,029 70,029 — — Loans held for sale 21,985 — 21,985 — Prepaid expenses and other current assets Interest rate lock commitments 496 — — 496 Forward sales commitments 4 — 4 — Total prepaid expenses and other current assets 500 — 4 496 Long-term investments U.S. treasury securities 30,978 30,978 — — Total assets $ 344,934 $ 322,449 $ 21,989 $ 496 Liabilities Accrued liabilities Interest rate lock commitments $ 58 $ — $ — $ 58 Forward sales commitments 57 — 57 — Total liabilities $ 115 $ — $ 57 $ 58
Summary of Fair Value Measurement Inputs and Valuation Techniques	following is a quantitative summary of key unobservable inputs used in the valuation of IRLCs: Key Inputs Valuation Technique March 31, 2020 December 31, 2019 Weighted-average pull-through rate Market pricing 75.1% 78.2%
Summary of Changes Fair Value Of Interest Rate Derivatives	The following is a summary of changes in the fair value of IRLCs for the period ended March 31, 2020: Balance, net—December 31, 2019 $ 430 Issuances of interest rate lock commitments 3,318 Settlements of interest rate lock commitments (2,494 ) Net gain recognized in earnings 371 Balance, net—March 31, 2020 $ 1,625 Changes in fair value recognized during the period relating to assets still held at March 31, 2020 $ 1,195
Investments in Debt and Marketable Equity Securities (and Certain Trading Assets)	The following table summarizes the cost or amortized cost, gross unrealized gains and losses, and estimated fair market value of our cash, money market funds, restricted cash, and available-for-sale investments. March 31, 2020 Fair Value Hierarchy Cost or Amortized Cost Unrealized Gains Unrealized Losses Estimated Fair Value Short-term Investments Long-term Investments Cash N/A $ 18,831 $ — $ — $ 18,831 $ — $ — Money markets funds Level 1 194,530 — — 194,530 — — Restricted cash N/A 16,772 — — 16,772 — — U.S. treasury securities Level 1 99,192 574 — 99,766 75,049 24,717 Agency bonds Level 1 2,000 — (6 ) 1,994 — 1,994 Total $ 331,325 $ 574 $ (6 ) $ 331,893 $ 75,049 $ 26,711 December 31, 2019 Fair Value Hierarchy Cost or Amortized Cost Unrealized Gains Unrealized Losses Estimated Fair Value Short-term Investments Long-term Investments Cash N/A $ 13,237 $ — $ — $ 13,237 $ — $ — Money markets funds Level 1 221,442 — — 221,442 — — Restricted cash N/A 12,769 — — 12,769 — — U.S. treasury securities Level 1 100,998 31 (22 ) 101,007 70,029 30,978 Total $ 348,446 $ 31 $ (22 ) $ 348,455 $ 70,029 $ 30,978

Inventory (Tables)

Inventory (Tables)	3 Months Ended
	Mar. 31, 2020
Inventory Disclosure [Abstract]
Schedule of Inventory, Current	a summary of inventory as of the dates presented: March 31, 2020 December 31, 2019 Homes for sale $ 47,887 $ 36,982 Homes not available for sale 3,667 3,163 Homes under improvement 19,095 34,445 Inventory $ 70,649 $ 74,590 The following is the inventory activity for the three months ended March 31, 2020 : Inventory as of January 1, 2020 $ 74,590 Purchases and capitalized improvements to inventory 68,384 Relief of inventory to cost of revenue (71,650 ) Lower of cost or net realizable value write-downs, net (675 ) Inventory as of March 31, 2020 $ 70,649

Property and Equipment (Tables)

Property and Equipment (Tables)	3 Months Ended
	Mar. 31, 2020
Property, Plant and Equipment [Abstract]
Property and Equipment	a summary of property and equipment as of the dates presented: Useful Lives (Years) March 31, 2020 December 31, 2019 Leasehold improvements Shorter of lease term or economic life $ 28,178 $ 28,141 Website and software development costs 2-3 30,141 27,602 Computer and office equipment 3 5,627 4,846 Software 3 1,126 595 Furniture 7 7,083 6,965 Construction in progress N/A 428 475 Property and equipment, gross 72,583 68,624 Accumulated depreciation and amortization (32,087 ) (29,047 ) Property and equipment, net $ 40,496 $ 39,577

Leases (Tables)

Leases (Tables)	3 Months Ended
	Mar. 31, 2020
Leases [Abstract]
Lease, Cost	Lease Term and Discount Rate March 31, 2020 December 31, 2019 Weighted average remaining operating lease term (years) 5.9 6.1 Weighted average remaining finance lease term (years) 3.5 3.8 Weighted average discount rate for operating leases 4.4 % 4.4 % Weighted average discount rate for finance leases 5.4 % 5.4 % Three Months Ended March 31, Supplemental Cash Flow Information 2020 2019 Cash paid for amounts included in the measurement of lease liabilities Operating cash flows from operating leases $ 3,464 $ 1,975 Operating cash flows from finance leases 3 — Financing cash flows from finance leases 12 — Right of use assets obtained in exchange for lease liabilities Operating leases $ 223 $ 33,953 Finance leases — — Three Months Ended March 31, Lease Cost Classification 2020 2019 Operating lease cost: Operating lease cost (1) Cost of revenue $ 2,138 $ 1,693 Operating lease cost (1) Operating expenses 1,094 855 Total operating lease cost $ 3,232 $ 2,548 Finance lease cost: Amortization of right-of-use assets Cost of revenue $ 17 $ — Interest on lease liabilities Cost of revenue 3 — Total finance lease cost $ 20 $ — (1) Includes lease expense with initial terms of twelve months or less of $226 and $821 for the three months ended March 31, 2020 and March 31, 2019 , respectively.
Lessee, Operating Lease, Liability, Maturity	Maturity of Lease Liabilities Operating Leases Finance Leases 2020, excluding the three months ended March 31, 2020 11,461 45 2021 14,289 60 2022 13,589 60 2023 12,612 46 2024 10,931 — Thereafter 16,915 — Total lease payments $ 79,797 $ 211 Less: Interest and other (1) 11,203 18 Present value of lease liabilities $ 68,594 $ 193 (1) Interest and other consists of interest expense related to capitalized right of use operating lease liabilities of $9,402 , interest expense related to capitalized right of use financing lease liabilities of $18 , commitments related to operating leases that have not yet commenced, and operating leases with initial terms of twelve months or less.

Commitments and Contingencies (

Commitments and Contingencies (Tables)	3 Months Ended
	Mar. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Schedule of Future Minimum Payments	future minimum payments due under these agreements as of March 31, 2020 : Leases Other Commitments 2020, excluding the three months ended March 31, 2020 $ 11,506 $ 8,716 2021 14,349 4,780 2022 13,649 5,439 2023 12,658 — 2024 and thereafter 27,846 — Total future minimum payments $ 80,008 $ 18,935

Acquired Intangible Assets (Tab

Acquired Intangible Assets (Tables)	3 Months Ended
	Mar. 31, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Finite-Lived Intangible Assets	The following are the details of our intangible assets subject to amortization as of the dates presented: March 31, 2020 December 31, 2019 Useful Lives (Years) Gross Accumulated Amortization Net Gross Accumulated Amortization Net Trade names 10 $ 1,040 $ (572 ) $ 468 $ 1,040 $ (546 ) $ 494 Developed technology 10 2,980 (1,639 ) 1,341 2,980 (1,564 ) 1,416 Customer relationships 10 860 (473 ) 387 860 (452 ) 408 $ 4,880 $ (2,684 ) $ 2,196 $ 4,880 $ (2,562 ) $ 2,318

Accrued Liabilities (Tables)

Accrued Liabilities (Tables)	3 Months Ended
	Mar. 31, 2020
Payables and Accruals [Abstract]
Schedule of Accrued Liabilities	The following are details of accrued liabilities as of the dates presented: March 31, 2020 December 31, 2019 Accrued compensation and benefits $ 37,300 $ 30,462 Miscellaneous accrued liabilities 21,156 7,560 Total accrued liabilities $ 58,456 $ 38,022

Other Payables (Tables)

Other Payables (Tables)	3 Months Ended
	Mar. 31, 2020
Payables and Accruals [Abstract]
Schedule of Other Payables	The following are details of other payables as of the dates presented: March 31, 2020 December 31, 2019 Customer deposits $ 10,793 $ 7,109 Miscellaneous payables 924 775 Total other payables $ 11,717 $ 7,884

Equity and Equity Compensatio_2

Equity and Equity Compensation Plans (Tables)	3 Months Ended
	Mar. 31, 2020
Share-based Payment Arrangement [Abstract]
Schedule of Reserved Shares of Common Stock	We have reserved shares of common stock for future issuance under our ESPP as follows: Three Months Ended March 31, 2020 Year Ended December 31, 2019 Shares available for issuance at beginning of period 3,330,271 2,890,973 Shares issued during the period — 490,717 Total shares available for future issuance at end of period 3,330,271 2,400,256 We have reserved shares of common stock for future issuance under our 2017 EIP as follows: March 31, 2020 December 31, 2019 Stock options issued and outstanding 7,028,719 7,792,181 Restricted stock units issued and outstanding 4,681,875 5,023,412 Shares available for future equity grants 11,899,400 7,100,499 Total shares reserved for future issuance 23,609,994 19,916,092
Schedule of Stock Option Activity	The following table summarizes activity for stock options for the three months ended March 31, 2020 : Number of Options Weighted- Average Exercise Price Weighted-Average Remaining Contractual Life (Years) Aggregate Intrinsic Value Outstanding as of January 1, 2020 7,792,181 $ 7.00 5.28 $ 111,122 Options exercised (738,398) 5.30 Options forfeited (20,798) 9.01 Options canceled (4,266) 10.80 Outstanding as of March 31, 2020 7,028,719 $ 7.17 5.12 $ 59,786 Options exercisable as of March 31, 2020 6,472,555 $ 6.54 4.93 $ 57,443
Schedule of Nonvested Restricted Stock Units Activity	The following table summarizes activity for restricted stock units for the three months ended March 31, 2020 : Restricted Stock Units Weighted Average Grant-Date Fair Value Outstanding as of January 1, 2020 5,023,412 $ 18.69 Granted 141,413 27.06 Vested (320,440 ) 19.36 Forfeited or canceled (162,510 ) 19.29 Outstanding as of March 31, 2020 4,681,875 $ 18.87
Schedule of Allocation of Share-based Compensation Costs	The following table details, for each period indicated, (i) our stock-based compensation, net of forfeitures, and the amount capitalized in internally developed software and (ii) changes to the probability of achieving outstanding performance-based equity awards, each as included in our consolidated statements of operations: Three Months Ended March 31, 2020 2019 Cost of revenue $ 1,638 $ 1,465 Technology and development 3,648 2,656 Marketing 375 286 General and administrative 1,550 1,999 Total stock-based compensation $ 7,211 $ 6,406

Net Loss per Share Attributab_2

Net Loss per Share Attributable to Common Stock (Tables)	3 Months Ended
	Mar. 31, 2020
Earnings Per Share [Abstract]
Schedule of Basic and Diluted Earnings Per Share	The following table sets forth the calculation of basic and diluted net loss per share attributable to common stock during the periods presented: Three Months Ended March 31, 2020 2019 Numerator: Net loss attributable to common stock—basic and diluted $ (60,117 ) $ (67,180 ) Denominator: Weighted average shares—basic and diluted 93,442,706 90,610,416 Net loss per share: Net loss per share attributable to common stock—basic and diluted $ (0.64 ) $ (0.74 )
Summary of Antidilutive Securities Excluded from Computation of Earnings Per Share	The following outstanding shares of common stock equivalents as of March 31, 2020 and 2019 were excluded from the computation of the diluted net loss per share for the periods presented because their effect would have been anti-dilutive: Three Months Ended March 31, 2020 2019 Stock options outstanding 7,028,719 8,713,162 Restricted stock units outstanding 4,681,875 3,588,275 Employee stock purchase plan 233,416 290,647 Total 11,944,010 12,592,084

Debt (Tables)

Debt (Tables)	3 Months Ended
	Mar. 31, 2020
Debt Disclosure [Abstract]
Schedule of Long-term Debt	The following table summarizes borrowings under these facilities as of the periods presented: Lender Borrowing Capacity as of March 31, 2020 Borrowings as of March 31, 2020 Borrowings as of December 31, 2019 Western Alliance Bank $ 24,500 $ 13,613 $ 8,489 Texas Capital Bank, N.A. 24,500 17,552 10,210 Flagstar Bank 20,000 11,421 2,603 Total $ 69,000 $ 42,586 $ 21,302 Lender Borrowing Capacity as of March 31, 2020 Borrowings as of Borrowings as of December 31, 2019 Goldman Sachs Bank USA $ 100,000 $ 8,901 $ 4,444 March 31, 2020 December 31, 2019 Principal $ 143,750 $ 143,750 Less: debt discount, net of amortization (19,840 ) (21,231 ) Less: debt issuance costs, net of amortization (2,618 ) (2,803 ) Net carrying amount of the convertible senior notes $ 121,292 $ 119,716
Interest Income and Interest Expense Disclosure	The following table sets forth total interest expense recognized related to the convertible senior notes for the periods presented: Three Months Ended March 31, 2020 2019 Amortization of debt discount $ 1,390 $ 1,329 Amortization of debt issuance costs 186 178 Total amortization of debt issuance costs and accretion of equity portion 1,576 1,507 Contractual interest expense 629 629 Total interest expense related to the notes $ 2,205 $ 2,136

Summary of Accounting Policie_2

Summary of Accounting Policies - Narrative (Details) $ in Thousands	1 Months Ended	3 Months Ended
	Dec. 31, 2018USD ($)	Mar. 31, 2020USD ($)investment_type	Mar. 31, 2019USD ($)
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of types of investments | investment_type		2
Payments to acquire equity securities	$ 2,000
Advertising expense		$ 22,529	$ 30,234
Advertising production costs		$ 174	$ 48

Segment Reporting and Revenue -

Segment Reporting and Revenue - Narrative (Details)	3 Months Ended
	Mar. 31, 2020segment
Segment Reporting [Abstract]
Number of operating segments	5
Number of reportable segments	2

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
	Mar. 31, 2020	Mar. 31, 2019
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Brokerage revenue	$ 190,995	$ 110,141
Cost of revenue	178,116	107,388
Gross profit	12,879	2,753
Operating expenses	70,309	70,205
Interest income	1,103	2,316
Interest expense	(2,444)	(2,136)
Other income (expense), net	(1,346)	92
Net loss	(60,117)	(67,180)
Operating Segments | Real estate services
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Brokerage revenue	108,636	85,890
Cost of revenue	93,562	80,784
Gross profit	15,074	5,106
Operating Segments | Properties
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Brokerage revenue	79,098	21,373
Cost of revenue	79,299	22,993
Gross profit	(201)	(1,620)
Other revenue
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Brokerage revenue	4,250	3,047
Cost of revenue	6,244	3,780
Gross profit	(1,994)	(733)
Intercompany eliminations
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Cost of revenue	(989)	(169)
Gross profit	0	0
Brokerage revenue | Operating Segments | Real estate services
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Brokerage revenue	102,351	81,314
Partner revenue | Operating Segments | Real estate services
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Brokerage revenue	$ 6,285	$ 4,576

Financial Instruments - Notiona

Financial Instruments - Notional Amounts of Derivatives (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Mar. 31, 2019
Interest rate lock commitments
Derivative [Line Items]
Notional amount	$ 73,382	$ 37,453
Forward sales commitments
Derivative [Line Items]
Notional amount	$ 66,448	$ 39,447

Financial Instruments - Amounts

Financial Instruments - Amounts of gains/(losses) recognized in income (Details) - Service revenue - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Interest rate lock commitments
Fair Value, Option, Quantitative Disclosures [Line Items]
Net gain recognized in earnings	$ 1,195	$ 446
Forward sales commitments
Fair Value, Option, Quantitative Disclosures [Line Items]
Net gain recognized in earnings	$ (1,571)	$ (244)

Financial Instruments - Schedul

Financial Instruments - Schedule of Assets, Liabilities, and Equity Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Assets
U.S. treasury securities	$ 75,049	$ 70,029
U.S. treasury securities	26,711	30,978
Fair Value, Measurements, Recurring
Assets
Loans held for sale	44,321	21,985
Derivative asset	2,025	500
U.S. treasury securities	26,711
Total assets	342,636	344,934
Liabilities
Total liabilities	2,016	115
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets
Loans held for sale	0	0
Derivative asset	0	0
U.S. treasury securities	26,711
Total assets	296,290	322,449
Liabilities
Total liabilities	0	0
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2)
Assets
Loans held for sale	44,321	21,985
Derivative asset	200	4
U.S. treasury securities	0
Total assets	44,521	21,989
Liabilities
Total liabilities	1,816	57
Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3)
Assets
Loans held for sale	0	0
Derivative asset	1,825	496
U.S. treasury securities	0
Total assets	1,825	496
Liabilities
Total liabilities	200	58
U.S. treasury securities | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets
U.S. treasury securities	75,049	70,029
U.S. treasury securities	24,717	30,978
U.S. treasury securities | Fair Value, Measurements, Recurring
Assets
U.S. treasury securities	75,049	70,029
U.S. treasury securities	24,717	30,978
U.S. treasury securities | Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets
U.S. treasury securities	75,049	70,029
U.S. treasury securities	24,717	30,978
U.S. treasury securities | Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2)
Assets
U.S. treasury securities	0	0
U.S. treasury securities	0	0
U.S. treasury securities | Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3)
Assets
U.S. treasury securities	0	0
U.S. treasury securities	0	0
Forward sales commitments | Fair Value, Measurements, Recurring
Assets
Derivative asset	200	4
Liabilities
Derivative liability	1,816	57
Forward sales commitments | Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets
Derivative asset	0	0
Liabilities
Derivative liability	0	0
Forward sales commitments | Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2)
Assets
Derivative asset	200	4
Liabilities
Derivative liability	1,816	57
Forward sales commitments | Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3)
Assets
Derivative asset	0	0
Liabilities
Derivative liability	0	0
Interest rate lock commitments | Fair Value, Measurements, Recurring
Assets
Derivative asset	1,825	496
Liabilities
Derivative liability	200	58
Interest rate lock commitments | Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets
Derivative asset	0	0
Liabilities
Derivative liability	0	0
Interest rate lock commitments | Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2)
Assets
Derivative asset	0	0
Liabilities
Derivative liability	0	0
Interest rate lock commitments | Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3)
Assets
Derivative asset	1,825	496
Liabilities
Derivative liability	200	58
Agency bonds | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets
U.S. treasury securities	0
U.S. treasury securities	1,994
Agency bonds | Fair Value, Measurements, Recurring
Assets
U.S. treasury securities	1,994
Agency bonds | Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets
U.S. treasury securities	1,994
Agency bonds | Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2)
Assets
U.S. treasury securities	0
Agency bonds | Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3)
Assets
U.S. treasury securities	0
Money market funds | Fair Value, Measurements, Recurring
Assets
Money market funds	194,530	221,442
Money market funds | Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets
Money market funds	194,530	221,442
Money market funds | Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2)
Assets
Money market funds	0	0
Money market funds | Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3)
Assets
Money market funds	$ 0	$ 0

Financial Instruments - Summary

Financial Instruments - Summary of Fair Value Measurement Inputs and Valuation Techniques (Details)	Mar. 31, 2020	Dec. 31, 2019
Interest rate lock commitments | Measurement Input, Weighted Average Pull Through Rate | Marketing pricing
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative instrument, measurement input	0.751	0.782

Financial Instruments - Summa_2

Financial Instruments - Summary of Changes in the Fair Value of IRLCs (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2020USD ($)
Changes of fair value of interest rate lock commitments [Roll Forward]
Balance, net—December 31, 2019	$ 430
Issuances of interest rate lock commitments	3,318
Settlements of interest rate lock commitments	(2,494)
Net gain recognized in earnings	371
Balance, net—March 31, 2020	1,625
Changes in fair value recognized during the period relating to assets still held at March 31, 2020	$ 1,195

Financial Instruments - Narrati

Financial Instruments - Narrative (Details) - USD ($)	3 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Fair Value Disclosures [Abstract]
Cost method investments	$ 2,000,000
Non-cash impairment charge	1,420,000
Available-for-sale debt securities in unrealized loss position	2,094,000	$ 46,550,000
Unrealized losses	6,000	22,000
Accrued interest	164,000	183,000
Available-for-sale, credit loss	$ 0	$ 0

Financial Instruments - Investm

Financial Instruments - Investments in Debt and Marketable Equity Securities Disclosure (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Cost or Amortized Cost
Cash and cash equivalents, at carrying value	$ 213,940	$ 234,679
Restricted cash	16,772	12,769
Cash, cash equivalents, and available-for-sale debt securities, amortized cost	331,325	348,446
Unrealized Gains (Losses)
Unrealized Gains	574	31
Unrealized Losses	(6)	(22)
Estimated Fair Value
Cash, cash equivalents, and available-for-sale debt securities	331,893	348,455
Short-term Investments
Short-term investments	75,049	70,029
Long-term Investments
Long-term investments	26,711	30,978
Fair Value, Inputs, Level 1 | U.S. treasury securities
Cost or Amortized Cost
Debt securities, available-for-sale, amortized cost	99,192	100,998
Unrealized Gains (Losses)
Unrealized Gains	574	31
Unrealized Losses	0	(22)
Estimated Fair Value
Debt securities, available-for-sale	99,766	101,007
Short-term Investments
Short-term investments	75,049	70,029
Long-term Investments
Long-term investments	24,717	30,978
Fair Value, Inputs, Level 1 | Agency bonds
Cost or Amortized Cost
Debt securities, available-for-sale, amortized cost	2,000
Unrealized Gains (Losses)
Unrealized Gains	0
Unrealized Losses	(6)
Estimated Fair Value
Debt securities, available-for-sale	1,994
Short-term Investments
Short-term investments	0
Long-term Investments
Long-term investments	1,994
Cash
Cost or Amortized Cost
Cash and cash equivalents, at carrying value	18,831	13,237
Money Market Funds | Fair Value, Inputs, Level 1
Cost or Amortized Cost
Cash and cash equivalents, at carrying value	$ 194,530	$ 221,442

Inventory (Details)

Inventory (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2020	Dec. 31, 2019
Inventory Disclosure [Abstract]
Homes for sale		$ 47,887	$ 36,982
Homes not available for sale		3,667	3,163
Homes under improvement		19,095	34,445
Inventory	$ 70,649	70,649	74,590
Lower of cost or net realizable value write-downs		$ 818	$ 143
Inventory, Current [Roll Forward]
Inventory as of January 1, 2020	74,590
Purchases and capitalized improvements to inventory	68,384
Relief of inventory to cost of revenue	(71,650)
Lower of cost or net realizable value write-downs, net	(675)
Inventory as of March 31, 2020	$ 70,649

Property and Equipment - Summar

Property and Equipment - Summary of Property and Equipment (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 72,583	$ 68,624
Accumulated depreciation and amortization	(32,087)	(29,047)
Property and equipment, net	40,496	39,577
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	28,178	28,141
Website and software development costs
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 30,141	27,602
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]
Useful Lives (Years)	3 years
Property and equipment, gross	$ 5,627	4,846
Software
Property, Plant and Equipment [Line Items]
Useful Lives (Years)	3 years
Property and equipment, gross	$ 1,126	595
Furniture
Property, Plant and Equipment [Line Items]
Useful Lives (Years)	7 years
Property and equipment, gross	$ 7,083	6,965
Construction in progress
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 428	$ 475

Property and Equipment - Narrat

Property and Equipment - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Property, Plant and Equipment [Abstract]
Depreciation and amortization	$ 3,186	$ 1,515
Capitalized computer software, gross	$ 2,677	$ 1,911

Leases - Narrative (Details)

Leases - Narrative (Details)	Mar. 31, 2020
Vehicles
Lessee, Lease, Description [Line Items]
Lessee, finance lease, term of contract	4 years
Minimum
Lessee, Lease, Description [Line Items]
Operating lease term	1 year
Maximum
Lessee, Lease, Description [Line Items]
Operating lease term	11 years

Leases - Summary of Lease Cost

Leases - Summary of Lease Cost (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Operating Leased Assets [Line Items]
Operating lease cost	$ 3,232	$ 2,548
Finance lease, right-of-use asset, amortization	17	0
Finance lease cost	20	0
Short-term lease cost	226	821
Cost of revenue
Operating Leased Assets [Line Items]
Operating lease cost	2,138	1,693
Finance lease, interest expense	3	0
Operating expense
Operating Leased Assets [Line Items]
Operating lease cost	$ 1,094	$ 855

Leases - Maturity of Lease Liab

Leases - Maturity of Lease Liabilities (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Operating leases
2020, excluding the three months ended March 31, 2020	$ 11,461
2021	14,289
2022	13,589
2023	12,612
2024	10,931
Thereafter	16,915
Total lease payments	79,797
Less: Interest and other	11,203
Present value of lease liabilities	68,594
Finance leases
2020, excluding the three months ended March 31, 2020	45
2021	60
2022	60
2023	46
2024	0
Thereafter	0
Total lease payments	211
Less: Interest and other	18
Present value of lease liabilities	193
Operating lease, capitalized interest expense	$ 9,402
Financing lease, capitalized interest expense		$ 18

Leases - Lease Term and Discoun

Leases - Lease Term and Discount Rate (Details)	Mar. 31, 2020	Dec. 31, 2019
Leases [Abstract]
Weighted average remaining operating lease term (years)	5 years 10 months 24 days	6 years 1 month 6 days
Weighted average remaining finance lease term (years)	3 years 6 months	3 years 9 months 18 days
Weighted average discount rate for operating leases	4.40%	4.40%
Weighted average discount rate for finance leases	5.40%	5.40%

Leases - Supplemental Cash Flow

Leases - Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Cash paid for amounts included in the measurement of lease liabilities
Operating cash flows from operating leases	$ 3,464	$ 1,975
Operating cash flows from finance leases	3	0
Financing cash flows from finance leases	12	0
Right of use assets obtained in exchange for lease liabilities
Operating leases	223	33,953
Finance leases	$ 0	$ 0

Commitments and Contingencies -

Commitments and Contingencies - Narrative (Details)	Mar. 31, 2020
Vehicles
Debt Instrument [Line Items]
Lessee, finance lease, term of contract	4 years
Minimum
Debt Instrument [Line Items]
Operating lease term	1 year
Maximum
Debt Instrument [Line Items]
Operating lease term	11 years

Commitments and Contingencies_2

Commitments and Contingencies - Summary of Future Minimum Payments (Details) $ in Thousands	Mar. 31, 2020USD ($)
Leases
Lessee, Lease Liability, Payments Remainder Of Fiscal Year	$ 11,506
2021	14,349
2022	13,649
2023	12,658
2024 and thereafter	27,846
Total lease payments	80,008
Other Commitments
2020, excluding the three months ended March 31, 2020	8,716
2021	4,780
2022	5,439
2023	0
2024 and thereafter	0
Total future minimum payments	$ 18,935

Acquired Intangible Assets - Sc

Acquired Intangible Assets - Schedule of Finite-Lived Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Gross	$ 4,880	$ 4,880
Accumulated Amortization	(2,684)	(2,562)
Net	$ 2,196	2,318
Trade names
Finite-Lived Intangible Assets [Line Items]
Useful Lives (Years)	10 years
Gross	$ 1,040	1,040
Accumulated Amortization	(572)	(546)
Net	$ 468	494
Developed technology
Finite-Lived Intangible Assets [Line Items]
Useful Lives (Years)	10 years
Gross	$ 2,980	2,980
Accumulated Amortization	(1,639)	(1,564)
Net	$ 1,341	1,416
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Useful Lives (Years)	10 years
Gross	$ 860	860
Accumulated Amortization	(473)	(452)
Net	$ 387	$ 408

Acquired Intangible Assets - Na

Acquired Intangible Assets - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization	$ 122	$ 122
Total	2,196
2020	488
2021	488
2022	488
2023	488
2024	$ 244

Accrued Liabilities (Details)

Accrued Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Payables and Accruals [Abstract]
Accrued compensation and benefits	$ 37,300	$ 30,462
Miscellaneous accrued liabilities	21,156	7,560
Total accrued liabilities	$ 58,456	$ 38,022

Other Payables (Details)

Other Payables (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Payables and Accruals [Abstract]
Customer deposits	$ 10,793	$ 7,109
Miscellaneous payables	924	775
Total other payables	$ 11,717	$ 7,884

Equity and Equity Compensatio_3

Equity and Equity Compensation Plans - Narrative (Details) - USD ($) $ / shares in Units, $ in Thousands	Jun. 01, 2019	Jul. 27, 2017	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019	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
Preferred stock, shares authorized (in shares)			10,000,000		10,000,000
Preferred stock, par value (in dollars per share)			$ 0.001		$ 0.001
Preferred stock, shares outstanding (in shares)			0		0
Unrecognized stock-based compensation, options			$ 2,255
Total grant date fair value, options vested			739	$ 1,449
Total grant date fair value, options exercised			15,251	8,682
Share-based payment expense			7,211	6,406
Stock-based compensation capitalized in property and equipment			$ 504	270
2004 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected life			10 years
Award vesting period			4 years
2017 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved (in shares)			23,609,994		19,916,092	7,898,159
Percentage of common stock, outstanding					5.00%
Expected life					10 years
Award vesting period			4 years
Restricted stock units outstanding (in shares)			4,681,875		5,023,412
2017 Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved (in shares)			3,330,271		2,400,256
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%
Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense, period for recognition			1 year 3 days
Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock units outstanding (in shares)			314,999
Share-based payment expense			$ (464)	$ 278
Restricted stock units outstanding
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Forfeited or canceled (in dollars per share)			$ 19.29
Unrecognized compensation expense, period for recognition			2 years 10 months 9 days
Unrecognized stock-based compensation			$ 77,435
Restricted stock units granted (in shares)			141,413
Restricted stock units outstanding (in shares)			4,681,875		5,023,412
Performance RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Achievement percentage of performance conditions			100.00%
Chief Executive Officer | Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted (in shares)	150,000
Options granted (in dollars per share)	$ 27.50
Maximum | Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage			200.00%
Maximum | Chief Executive Officer | Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted (in shares)	300,000
Minimum | Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage			0.00%
January To December 2018 Awards [Member] | Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based payment expense			$ (617)
January To December 2019 Awards [Member] | Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based payment expense			$ 153

Equity and Equity Compensatio_4

Equity and Equity Compensation Plans - Summary of Common Stock Reserved for Future Issuance (in shares) (Details) - shares	Mar. 31, 2020	Dec. 31, 2019	Jul. 26, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares underlying outstanding stock options (in shares)	7,028,719	7,792,181
Equity Incentive Plans
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares underlying outstanding stock options (in shares)	7,028,719	7,792,181
Shares underlying outstanding restricted stock units (in shares)	4,681,875	5,023,412
Shares available for future equity grants (in shares)	11,899,400	7,100,499
Common stock reserved (in shares)	23,609,994	19,916,092	7,898,159
2017 Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for issuance on January 1, 2020 and 2019, respectively (in shares)	3,330,271	2,890,973
Shares issued since January 1, 2020 and 2019, respectively (in shares)	0	490,717
Common stock reserved (in shares)	3,330,271	2,400,256

Equity and Equity Compensatio_5

Equity and Equity Compensation Plans - Schedule of Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Number Of Options
Outstanding, beginning balance (in shares)	7,792,181
Options exercised (in shares)	(738,398)
Options forfeited (in shares)	(20,798)
Options canceled (in shares)	(4,266)
Outstanding, ending balance (in shares)	7,028,719	7,792,181
Options exercisable at period end (in shares)	6,472,555
Weighted- Average Exercise Price
Outstanding, beginning balance (in dollars per share)	$ 7
Options exercised (in dollars per share)	5.30
Options forfeited (in dollars per share)	9.01
Options canceled (in dollars per share)	10.80
Outstanding, ending balance (in dollars per share)	7.17	$ 7
Options exercisable at period end (in dollars per share)	$ 6.54
Weighted-Average Remaining Contractual Life (Years)
Weighted average remaining contractual life outstanding	5 years 1 month 13 days	5 years 3 months 10 days
Weighted average remaining contractual life exercisable	4 years 11 months 4 days
Aggregate Intrinsic Value
Options outstanding, Aggregate intrinsic value	$ 59,786	$ 111,122
Options exercisable, Aggregate intrinsic value	$ 57,443

Equity and Equity Compensatio_6

Equity and Equity Compensation Plans - Schedule of Restricted Stock Unit Activity (Details) - Restricted stock units outstanding	3 Months Ended
	Mar. 31, 2020$ / sharesshares
Restricted Stock Units
Unvested outstanding at beginning of period (in shares) | shares	5,023,412
Granted (in shares) | shares	141,413
Vested (in shares) | shares	(320,440)
Forfeited or canceled (in shares) | shares	(162,510)
Unvested outstanding at end of period (in shares) | shares	4,681,875
Weighted-Average Grant Date Fair Value
Unvested outstanding at beginning of period (in dollars per share) | $ / shares	$ 18.69
Granted (in dollars per share) | $ / shares	27.06
Vested (in dollars per share) | $ / shares	19.36
Forfeited or canceled (in dollars per share) | $ / shares	19.29
Unvested outstanding at end of period (in dollars per share) | $ / shares	$ 18.87

Equity and Equity Compensatio_7

Equity and Equity Compensation Plans - Allocation of Stock-based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation	$ 7,211	$ 6,406
Cost of revenue
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation	1,638	1,465
Technology and development
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation	3,648	2,656
Marketing
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation	375	286
General and administrative
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation	$ 1,550	$ 1,999

Net Loss per Share Attributab_3

Net Loss per Share Attributable to Common Stock - Computation of Net Loss Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Numerator:
Net loss attributable to common stock—basic and diluted	$ (60,117)	$ (67,180)
Denominator:
Weighted average shares —basic and diluted (in shares)	93,442,706	90,610,416
Net loss per share attributable to common stock—basic and diluted (in dollars per share)	$ (0.64)	$ (0.74)

Net Loss per Share Attributab_4

Net Loss per Share Attributable to Common Stock - Summary of Anti-dilutive Stock Equivalents (Details) - USD ($)	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from earnings per share (in shares)	11,944,010	12,592,084
Effect on basic earnings per share, dilutive convertible securities	$ 0
Stock options outstanding
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from earnings per share (in shares)	7,028,719	8,713,162
Restricted stock units outstanding
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from earnings per share (in shares)	4,681,875	3,588,275
Employee stock purchase plan
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from earnings per share (in shares)	233,416	290,647

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2017
Income Tax Disclosure [Abstract]
Effective tax rate	0.00%	0.00%
Operating loss unavailable for carryforward				$ 1,538
Federal Jurisdiction
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards			$ 195,133
Operating loss carryforwards, not subject to expiration			109,484
State and Local Jurisdiction
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards			$ 10,421

Debt - Warehouse Lines of Credi

Debt - Warehouse Lines of Credit (Details) - USD ($)	Mar. 31, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Warehouse credit facilities	$ 42,586,000	$ 21,302,000
Warehouse Agreement Borrowings
Debt Instrument [Line Items]
Borrowing Capacity as of March 31, 2020	69,000,000
Warehouse credit facilities	42,586,000	21,302,000
Western Alliance Bank | Warehouse Agreement Borrowings
Debt Instrument [Line Items]
Borrowing Capacity as of March 31, 2020	24,500,000
Warehouse credit facilities	13,613,000	8,489,000
Texas Capital Bank, N.A. | Warehouse Agreement Borrowings
Debt Instrument [Line Items]
Borrowing Capacity as of March 31, 2020	24,500,000
Warehouse credit facilities	17,552,000	10,210,000
Flagstar Bank | Warehouse Agreement Borrowings
Debt Instrument [Line Items]
Borrowing Capacity as of March 31, 2020	20,000,000
Warehouse credit facilities	$ 11,421,000	$ 2,603,000

Debt - Secured Revolving Credit

Debt - Secured Revolving Credit Facility (Details) - Goldman Sachs Bank USA - Revolving Credit Facility - USD ($)	Mar. 31, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	$ 100,000,000
Line of Credit Facility, Borrowings	$ 8,901,000	$ 4,444,000

Debt - Narrative (Details)

Debt - Narrative (Details) - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019	Dec. 31, 2018	Jul. 23, 2018
Debt Instrument [Line Items]
Inventory	$ 70,649,000		$ 74,590,000
Cash, cash equivalents, restricted cash and restricted cash equivalents	230,712,000	$ 406,089,000	247,448,000	$ 439,055,000
1.75% Convertible Senior Notes due 2023
Debt Instrument [Line Items]
Stated interest rate					1.75%
Amortization of debt issuance costs	186,000	178,000
Interest expense, debt	629,000	$ 629,000
Aggregated principal amount					$ 143,750,000
Debt instrument, interest rate, effective percentage					7.25%
Fair Value, Inputs, Level 2 | 1.75% Convertible Senior Notes due 2023
Debt Instrument [Line Items]
Debt instrument, fair value	$ 130,801,000		$ 142,672,000
Revolving Credit Facility
Debt Instrument [Line Items]
Debt, weighted average interest rate	3.77%		4.45%
Net assets	$ 53,445,000		$ 16,200,000
Inventory	44,455,000		7,456,000
Cash, cash equivalents, restricted cash and restricted cash equivalents	5,648,000		$ 5,663,000
Amortization of debt issuance costs	154,000
Interest expense, debt	$ 80,000
Western Alliance Bank | Warehouse Agreement Borrowings | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate	2.00%
Stated interest rate	3.50%
Debt, weighted average interest rate	3.52%		3.79%
Texas Capital Bank, N.A. | Warehouse Agreement Borrowings
Debt Instrument [Line Items]
Stated interest rate	3.50%
Debt, weighted average interest rate	3.50%		3.51%
Decrease in rate of interest accruing on outstanding principal	0.50%
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%
Maximum | Goldman Sachs Bank USA | Revolving Credit Facility
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate	2.65%
Line of Credit | Revolving Credit Facility | Flagstar Warehouse Credit Facility
Debt Instrument [Line Items]
Stated interest rate	3.00%
Debt, weighted average interest rate	3.36%		3.69%
Debt instrument, termination notice period			30 days
Line of Credit | Revolving Credit Facility | London Interbank Offered Rate (LIBOR) | Flagstar Warehouse Credit Facility
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate	2.00%

Debt - Components of The Notes

Debt - Components of The Notes (Details) - 1.75% Convertible Senior Notes due 2023 - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Principal	$ 143,750	$ 143,750
Less: debt discount, net of amortization	(19,840)	(21,231)
Less: debt issuance costs, net of amortization	(2,618)	(2,803)
Net carrying amount of the convertible senior notes	$ 121,292	$ 119,716

Debt - Interest Expense (Detail

Debt - Interest Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Jul. 23, 2018
Debt Instrument [Line Items]
Total amortization of debt issuance costs and accretion of equity portion	$ 1,730	$ 1,507
Total interest expense related to the Notes	2,444	2,136
1.75% Convertible Senior Notes due 2023
Debt Instrument [Line Items]
Amortization of debt discount	1,390	1,329
Amortization of debt issuance costs	186	178
Total amortization of debt issuance costs and accretion of equity portion	1,576	1,507
Contractual interest expense	629	629
Total interest expense related to the Notes	$ 2,205	$ 2,136
Effective interest rate of the liability component			7.25%

Subsequent Events (Details)

Subsequent Events (Details)	Apr. 01, 2020USD ($)$ / sharesshares	May 31, 2020employee	Apr. 30, 2020USD ($)employee	Mar. 31, 2020USD ($)
Subsequent Event
Subsequent Event [Line Items]
Proceeds from issuance or sale of equity	$ 110,000,000
Number of positions eliminated | employee			400
Number of positions eliminated, period percent			10.00%
Restructuring charges			$ 4,400,000
Number of employees on furlough | employee			1,000
Number of employees returned from furlough | employee		135
Employee transition pay, pre-tax charge			$ 1,000,000
Subsequent Event | Common Stock
Subsequent Event [Line Items]
Stock issued during period shares new issues (in shares) | shares	4,484,305
Shares issued price per share (in dollar per share) | $ / shares	$ 15.61
Subsequent Event | Series A Convertible Preferred Stock
Subsequent Event [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
Warehouse Agreement Borrowings
Subsequent Event [Line Items]
Line of credit facility, maximum borrowing capacity				$ 69,000,000
Warehouse Agreement Borrowings | Flagstar Bank
Subsequent Event [Line Items]
Line of credit facility, maximum borrowing capacity				$ 20,000,000
Warehouse Agreement Borrowings | Flagstar Bank | Subsequent Event
Subsequent Event [Line Items]
Line of credit facility, maximum borrowing capacity			$ 24,500,000