Description of Business and Summary of Significant Accounting Policies	6 Months Ended
Jun. 30, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business and Summary of Significant Accounting Policies	Description of Business and Summary of Significant Accounting Policies: Description of Business—Redfin Corporation (“Redfin” or the “Company”) was incorporated in October 2002 and is headquartered in Seattle, Washington. The Company operates an online real estate marketplace and provides real estate services, including assisting individuals to purchase or sell their residential property. The Company’s wholly owned subsidiaries also provide title and settlement services and originate mortgages. The Company has operations located in multiple states nationwide. Basis of Presentation—The condensed consolidated financial statements and accompanying notes have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”). Certain information and disclosures normally included in consolidated financial statements presented in accordance with GAAP have been condensed or omitted. Accordingly, these condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and the related notes for the year ended December 31, 2016 included in our Prospectus dated July 28, 2017, filed with the SEC on July 28, 2017 pursuant to Rule 424(b)(4) under the Securities Act of 1933, as ameded ("Prospectus"). The Company had no components of other comprehensive income (loss) during any of the years presented, as such, a consolidated statement of comprehensive income (loss) is not presented. All amounts are presented in thousands, except share and per share data. The unaudited condensed 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 June 30, 2017, our results of operations for the three and six month periods ended June 30, 2017 and 2016, and our cash flows for the six month periods ended June 30, 2017 and 2016. The results of the three and six month periods ended June 30, 2017 are not necessarily indicative of the results to be expected for the year ending December 31, 2017 or for any interim period or for any other future year. Principles of Consolidation—The unaudited condensed consolidated interim financial statements include the accounts of Redfin and its wholly owned subsidiaries. Intercompany transactions and balances have been eliminated. Certain Significant Risks and Business Uncertainties—The Company is subject to the risks and challenges associated with companies at a similar stage of development. These include dependence on key individuals, successful development and marketing of its offerings, and competition with larger companies with greater financial, technical, and marketing resources. Further, during the period required to achieve substantially higher revenue in order to become profitable, the Company may require additional funds that may not be readily available or may not be on terms that are acceptable to the Company. The Company operates in the online real estate marketplace and, accordingly, can be affected by a variety of factors. For example, management of the Company believes that any of the following factors could have a significant negative effect on the Company’s future financial position, results of operations, and cash flows: unanticipated fluctuations in operating results due to seasonality and cyclicality in the real estate industry, changes in home sale prices and transaction volumes, the Company’s ability to increase market share, competition and U.S. economic conditions. Reverse Stock Split—On July 8, 2017, the Company’s board of directors approved an amendment to the Company's certificate of incorporation to effect a reverse split of shares of the issued and outstanding common stock and redeemable convertible preferred stock at a 3-to-1 ratio. The reverse stock split was approved by the Company’s stockholders and effected on July 10, 2017. The par value of the common stock and the par value of the redeemable convertible preferred stock were not adjusted as a result of the reverse stock split. All issued and outstanding shares of common stock and redeemable convertible preferred stock, dividend rates, conversion rates, options to purchase common stock, exercise prices, and the related per-share amounts contained in these consolidated financial statements have been retroactively adjusted to reflect this reverse stock split for all periods presented. Use of Estimates—The preparation of the unaudited condensed consolidated interim 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. Management’s more significant estimates include, but are not limited to, valuation of deferred income taxes, stock-based compensation, fair value of common stock and redeemable convertible preferred stock, capitalization of website development costs, recoverability of intangible assets with finite lives, and the fair value of reporting units for purposes of evaluating goodwill for impairment. Management bases its estimates on historical experience, and on various other market-specific relevant assumptions that management believes to be reasonable, under the circumstances. The amounts ultimately realized from the affected assets or ultimately recognized as liabilities will depend on, among other factors, general business conditions and could differ materially in the near term from the carrying amounts reflected in the consolidated financial statements. Unaudited Pro Forma Consolidated Balance Sheet Data and Pro Forma Net Income (Loss) per Share Attributable to Common Stock—The pro forma information has been prepared assuming that, upon the completion of the public offering, all of the Company’s redeemable convertible preferred stock outstanding will automatically convert into shares of common stock, based on the provisions in the Company’s Amended and Restated Certificate of Incorporation. The Company prepared the pro forma basic and diluted net income (loss) per share attributable to common stock for the three and six months ended June 30, 2017, assuming the automatic conversion of the redeemable convertible preferred stock as if the initial public offering had been completed on January 1, 2017. On August 2, 2017 the Company completed an initial public offering ("IPO"). Significant Accounting Policies—There have been no material changes to our significant accounting policies and estimates during the six months ended June 30, 2017, from the significant accounting policies described in the Prospectus. Deferred Offering Costs—Deferred offering costs, including legal, accounting and other fees and costs relating to our planned initial public offering, are capitalized and included as a noncurrent asset in the consolidated balance sheets. The deferred offering costs will be offset against initial public offering proceeds upon the closing of the initial public offering within equity. There were $720 and $2,299 of capitalized deferred offering costs as of December 31, 2016, and June 30, 2017, respectively. Other Current Assets—In April 2017, the Company received $8,470 from the landlord of the Company's new corporate headquarters for reimbursable leasehold improvement costs. The Company had previously recorded a receivable for this amount. The receipt of reimbursable leasehold improvements is classified as a cash inflow of cash in the operating section in the Company's consolidated statement of cash flows for the six months ended June 30, 2017. Additionally, in January 2017, RDFN Ventures, Inc. (“Redfin Now”), a wholly owned subsidiary of the Company, began purchasing properties with the intent of resale. Direct property acquisition and improvement costs are capitalized and tracked directly with each specific property. These are stated at cost unless the utility of the properties is no longer as great as their cost, in which case it is written down to “market”. As of December 31, 2016 and June 30, 2017 there were $0 and $1,582 respectively, in home inventories included in other current assets. Of the $1,582 in home inventories at June 30, 2017, $365 were subject to active listings and $1,217 were in process and being made ready for sale. Recently Adopted Accounting Pronouncements—In January 2017, the Financial Accounting Standard Board (“FASB”) issued guidance simplifying the test for goodwill impairment. Step 2 from the goodwill impairment test is no longer required, instead requiring an entity to recognize a goodwill impairment charge for the amount by which the goodwill carrying amount exceeds the reporting unit’s fair value. This guidance is effective for interim and annual goodwill impairment tests in fiscal years beginning after December 15, 2019, and early adoption is permitted. This guidance must be applied on a prospective basis. The Company adopted this guidance for interim and annual goodwill impairment tests performed on testing dates after January 1, 2017. The Company performs its goodwill assessment annually on October 1 of each year or as events merit. The Company does not expect the adoption of this guidance to impact the Company’s financial position, results of operations or cash flows. In March 2016, the FASB issued guidance on several aspects of the accounting for share-based payment transactions, including the income tax consequences, impact of forfeitures, classification of awards as either equity or liabilities and classification on the statement of cash flows. This guidance is effective for interim and annual reporting periods beginning after December 15, 2016, and early adoption is permitted. The Company adopted this guidance on January 1, 2017 using the modified retrospective approach through a cumulative-effect adjustment of $552 to beginning accumulated deficit, and the Company elected to account for forfeitures as they occur beginning on January 1, 2017. The adoption of this guidance did not have a material impact on the Company’s financial position, results of operations or cash flows. In November 2015, the FASB issued guidance on the balance sheet classification of deferred taxes. This standard requires that deferred tax liabilities and assets be classified as noncurrent in a classified statement of financial position. This guidance is effective for interim and annual reporting periods beginning after December 15, 2016, and early adoption is permitted. The Company has prospectively adopted this guidance as of January 1, 2016. The adoption of this guidance had no effect on the Company’s financial position. Recently Issued Accounting Pronouncements—In November 2016, the FASB issued guidance on the classification and presentation of changes in restricted cash on the statement of cash flows. This guidance is effective for interim and annual reporting periods beginning after December 15, 2017, and early adoption is permitted. The adoption of this guidance requires a retrospective transition method to each period presented. The Company expects to adopt this guidance on January 1, 2018. The Company is currently evaluating the effect the adoption of this guidance will have on the Company’s cash flows. In August 2016, the FASB issued guidance on the classification of certain cash receipts and cash payments in the statement of cash flows. This new standard will make eight targeted changes to how cash receipts and cash payments are presented and classified in the statement of cash flows. The new standard is effective for fiscal years beginning after December 15, 2017, which means that it will be effective for the Company in its fiscal year beginning January 1, 2018. The new standard will require adoption on a retrospective basis unless it is impracticable to apply, in which case the Company would be required to apply the amendments prospectively as of the earliest date practicable. The Company is currently evaluating the effect the adoption of this guidance will have on the Company’s statement of cash flows. In February 2016, the FASB issued guidance on leases. This standard requires the recognition of a right-of-use asset and lease liability on the balance sheet for all leases. This standard also requires more detailed disclosures to enable users of financial statements to understand the amount, timing, and uncertainty of cash flows arising from leases. This guidance is effective for interim and annual reporting periods beginning after December 15, 2018, and should be applied through a modified retrospective transition approach for leases existing at, or entered into after, the beginning of the earliest comparative period presented in the financial statements, and early adoption is permitted. The Company expects to adopt this guidance on January 1, 2019. The Company believes adoption of this standard will have a significant effect on its financial position. In May 2014, the FASB issued guidance on revenue recognition. This guidance provides that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. This guidance also requires more detailed disclosures to enable users of financial statements to understand the nature, amount, timing, and uncertainty of revenue and cash flows arising from contracts with customers. The original effective date of this guidance was for interim and annual reporting periods beginning after December 15, 2016, early adoption is not permitted, and the guidance must be applied retrospectively or modified retrospectively. In July 2015, the FASB approved an optional one-year deferral of the effective date. As a result, the Company expects to adopt this guidance on January 1, 2018. In 2016, the FASB issued final amendments to clarify the implementation guidance for principal versus agent considerations, identifying performance obligations and the accounting for licenses of intellectual property. The Company expects to adopt this guidance on January 1, 2018. While the Company does not expect the adoption of this standard to have a significant effect on the Company’s financial position, results of operations and cash flows, the Company continues to evaluate its current arrangements with customers and related performance obligations therein and when such performance obligations are satisfied. Additionally the Company continues to evaluate the enhanced disclosure requirements under the new standard.

Description of Business and Summary of Significant Accounting Policies:

Description of Business—Redfin Corporation (“Redfin” or the “Company”) was incorporated in October 2002 and is headquartered in Seattle, Washington. The Company operates an online real estate marketplace and provides real estate services, including assisting individuals to purchase or sell their residential property. The Company’s wholly owned subsidiaries also provide title and settlement services and originate mortgages. The Company has operations located in multiple states nationwide.

Basis of Presentation—The condensed consolidated financial statements and accompanying notes have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”). Certain information and disclosures normally included in consolidated financial statements presented in accordance with GAAP have been condensed or omitted. Accordingly, these condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and the related notes for the year ended December 31, 2016 included in our Prospectus dated July 28, 2017, filed with the SEC on July 28, 2017 pursuant to Rule 424(b)(4) under the Securities Act of 1933, as ameded ("Prospectus"). The Company had no components of other comprehensive income (loss) during any of the years presented, as such, a consolidated statement of comprehensive income (loss) is not presented. All amounts are presented in thousands, except share and per share data.

The unaudited condensed 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 June 30, 2017, our results of operations for the three and six month periods ended June 30, 2017 and 2016, and our cash flows for the six month periods ended June 30, 2017 and 2016. The results of the three and six month periods ended June 30, 2017 are not necessarily indicative of the results to be expected for the year ending December 31, 2017 or for any interim period or for any other future year.

Principles of Consolidation—The unaudited condensed consolidated interim financial statements include the accounts of Redfin and its wholly owned subsidiaries. Intercompany transactions and balances have been eliminated.

Certain Significant Risks and Business Uncertainties—The Company is subject to the risks and challenges associated with companies at a similar stage of development. These include dependence on key individuals, successful development and marketing of its offerings, and competition with larger companies with greater financial, technical, and marketing resources. Further, during the period required to achieve substantially higher revenue in order to become profitable, the Company may require additional funds that may not be readily available or may not be on terms that are acceptable to the Company.

The Company operates in the online real estate marketplace and, accordingly, can be affected by a variety of factors. For example, management of the Company believes that any of the following factors could have a significant negative effect on the Company’s future financial position, results of operations, and cash flows: unanticipated fluctuations in operating results due to seasonality and cyclicality in the real estate industry, changes in home sale prices and transaction volumes, the Company’s ability to increase market share, competition and U.S. economic conditions.

Reverse Stock Split—On July 8, 2017, the Company’s board of directors approved an amendment to the Company's certificate of incorporation to effect a reverse split of shares of the issued and outstanding common stock and redeemable convertible preferred stock at a 3-to-1 ratio. The reverse stock split was approved by the Company’s stockholders and effected on July 10, 2017. The par value of the common stock and the par value of the redeemable convertible preferred stock were not adjusted as a result of the reverse stock split. All issued and outstanding shares of common stock and redeemable convertible preferred stock, dividend rates, conversion rates, options to purchase common stock, exercise prices, and the related per-share amounts contained in these consolidated financial statements have been retroactively adjusted to reflect this reverse stock split for all periods presented.

Use of Estimates—The preparation of the unaudited condensed consolidated interim 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. Management’s more significant estimates include, but are not limited to, valuation of deferred income taxes, stock-based compensation, fair value of common stock and redeemable convertible preferred stock, capitalization of website development costs, recoverability of intangible assets with finite lives, and the fair value of reporting units for purposes of evaluating goodwill for impairment. Management bases its estimates on historical experience, and on various other market-specific relevant assumptions that management believes to be reasonable, under the circumstances. The amounts ultimately realized from the affected assets or ultimately recognized as liabilities will depend on, among other factors, general business conditions and could differ materially in the near term from the carrying amounts reflected in the consolidated financial statements.

Unaudited Pro Forma Consolidated Balance Sheet Data and Pro Forma Net Income (Loss) per Share Attributable to Common Stock—The pro forma information has been prepared assuming that, upon the completion of the public offering, all of the Company’s redeemable convertible preferred stock outstanding will automatically convert into shares of common stock, based on the provisions in the Company’s Amended and Restated Certificate of Incorporation. The Company prepared the pro forma basic and diluted net income (loss) per share attributable to common stock for the three and six months ended June 30, 2017, assuming the automatic conversion of the redeemable convertible preferred stock as if the initial public offering had been completed on January 1, 2017. On August 2, 2017 the Company completed an initial public offering ("IPO").

Significant Accounting Policies—There have been no material changes to our significant accounting policies and estimates during the six months ended June 30, 2017, from the significant accounting policies described in the Prospectus.

Deferred Offering Costs—Deferred offering costs, including legal, accounting and other fees and costs relating to our planned initial public offering, are capitalized and included as a noncurrent asset in the consolidated balance sheets. The deferred offering costs will be offset against initial public offering proceeds upon the closing of the initial public offering within equity. There were $720 and $2,299 of capitalized deferred offering costs as of December 31, 2016, and June 30, 2017, respectively.

Other Current Assets—In April 2017, the Company received $8,470 from the landlord of the Company's new corporate headquarters for reimbursable leasehold improvement costs. The Company had previously recorded a receivable for this amount. The receipt of reimbursable leasehold improvements is classified as a cash inflow of cash in the operating section in the Company's consolidated statement of cash flows for the six months ended June 30, 2017. Additionally, in January 2017, RDFN Ventures, Inc. (“Redfin Now”), a wholly owned subsidiary of the Company, began purchasing properties with the intent of resale. Direct property acquisition and improvement costs are capitalized and tracked directly with each specific property. These are stated at cost unless the utility of the properties is no longer as great as their cost, in which case it is written down to “market”. As of December 31, 2016 and June 30, 2017 there were $0 and $1,582 respectively, in home inventories included in other current assets. Of the $1,582 in home inventories at June 30, 2017, $365 were subject to active listings and $1,217 were in process and being made ready for sale.

Recently Adopted Accounting Pronouncements—In January 2017, the Financial Accounting Standard Board (“FASB”) issued guidance simplifying the test for goodwill impairment. Step 2 from the goodwill impairment test is no longer required, instead requiring an entity to recognize a goodwill impairment charge for the amount by which the goodwill carrying amount exceeds the reporting unit’s fair value. This guidance is effective for interim and annual goodwill impairment tests in fiscal years beginning after December 15, 2019, and early adoption is permitted. This guidance must be applied on a prospective basis. The Company adopted this guidance for interim and annual goodwill impairment tests performed on testing dates after January 1, 2017. The Company performs its goodwill assessment annually on October 1 of each year or as events merit. The Company does not expect the adoption of this guidance to impact the Company’s financial position, results of operations or cash flows.

In March 2016, the FASB issued guidance on several aspects of the accounting for share-based payment transactions, including the income tax consequences, impact of forfeitures, classification of awards as either equity or liabilities and classification on the statement of cash flows. This guidance is effective for interim and annual reporting periods beginning after December 15, 2016, and early adoption is permitted. The Company adopted this guidance on January 1, 2017 using the modified retrospective approach through a cumulative-effect adjustment of $552 to beginning accumulated deficit, and the Company elected to account for forfeitures as they occur beginning on January 1, 2017. The adoption of this guidance did not have a material impact on the Company’s financial position, results of operations or cash flows.

In November 2015, the FASB issued guidance on the balance sheet classification of deferred taxes. This standard requires that deferred tax liabilities and assets be classified as noncurrent in a classified statement of financial position. This guidance is effective for interim and annual reporting periods beginning after December 15, 2016, and early adoption is permitted. The Company has prospectively adopted this guidance as of January 1, 2016. The adoption of this guidance had no effect on the Company’s financial position.

Recently Issued Accounting Pronouncements—In November 2016, the FASB issued guidance on the classification and presentation of changes in restricted cash on the statement of cash flows. This guidance is effective for interim and annual reporting periods beginning after December 15, 2017, and early adoption is permitted. The adoption of this guidance requires a retrospective transition method to each period presented. The Company expects to adopt this guidance on January 1, 2018. The Company is currently evaluating the effect the adoption of this guidance will have on the Company’s cash flows.

In August 2016, the FASB issued guidance on the classification of certain cash receipts and cash payments in the statement of cash flows. This new standard will make eight targeted changes to how cash receipts and cash payments are presented and classified in the statement of cash flows. The new standard is effective for fiscal years beginning after December 15, 2017, which means that it will be effective for the Company in its fiscal year beginning January 1, 2018. The new standard will require adoption on a retrospective basis unless it is impracticable to apply, in which case the Company would be required to apply the amendments prospectively as of the earliest date practicable. The Company is currently evaluating the effect the adoption of this guidance will have on the Company’s statement of cash flows.

In February 2016, the FASB issued guidance on leases. This standard requires the recognition of a right-of-use asset and lease liability on the balance sheet for all leases. This standard also requires more detailed disclosures to enable users of financial statements to understand the amount, timing, and uncertainty of cash flows arising from leases. This guidance is effective for interim and annual reporting periods beginning after December 15, 2018, and should be applied through a modified retrospective transition approach for leases existing at, or entered into after, the beginning of the earliest comparative period presented in the financial statements, and early adoption is permitted. The Company expects to adopt this guidance on January 1, 2019. The Company believes adoption of this standard will have a significant effect on its financial position.

In May 2014, the FASB issued guidance on revenue recognition. This guidance provides that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. This guidance also requires more detailed disclosures to enable users of financial statements to understand the nature, amount, timing, and uncertainty of revenue and cash flows arising from contracts with customers. The original effective date of this guidance was for interim and annual reporting periods beginning after December 15, 2016, early adoption is not permitted, and the guidance must be applied retrospectively or modified retrospectively. In July 2015, the FASB approved an optional one-year deferral of the effective date. As a result, the Company expects to adopt this guidance on January 1, 2018. In 2016, the FASB issued final amendments to clarify the implementation guidance for principal versus agent considerations, identifying performance obligations and the accounting for licenses of intellectual property. The Company expects to adopt this guidance on January 1, 2018. While the Company does not expect the adoption of this standard to have a significant effect on the Company’s financial position, results of operations and cash flows, the Company continues to evaluate its current arrangements with customers and related performance obligations therein and when such performance obligations are satisfied. Additionally the Company continues to evaluate the enhanced disclosure requirements under the new standard.