Summary of Accounting Policies (Policies)	3 Months Ended
Mar. 31, 2022
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, 2021 that is included in this quarterly report is derived from the audited consolidated financial statements and notes for the year ended December 31, 2021 included in Item 8 in our annual report for the year ended December 31, 2021. 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, 2022, our statements of comprehensive loss, and statements of changes in mezzanine equity and stockholders’ equity for the three months ended March 31, 2022 and 2021, as well as our statements of cash flows for the three months ended March 31, 2022 and 2021. The results for the three months ended March 31, 2022 are not necessarily indicative of the results to be expected for the year ending December 31, 2022 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 Corporation and its wholly owned subsidiaries, including those entities in which we have a variable interest and of which we are the primary beneficiary. Intercompany transactions and balances have been eliminated.
Use of Estimates	Use of Estimates—The preparation of consolidated financial statements, in conformity with GAAP, requires our management to make estimates and assumptions that affect the reported amounts of assets and liabilities and results of operations during the respective periods. Our estimates include, but are not limited to, valuation of deferred income taxes, stock-based compensation, net realizable value of inventory, capitalization of website and software development costs, the incremental borrowing rate for the determination of the present value of lease payments, recoverability of intangible assets with finite lives, fair value of our mortgage loans held for sale, estimated useful life of intangible assets, fair value of reporting units for purposes of allocating and evaluating goodwill for impairment, and current expected credit losses on certain financial assets. 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.
Restructuring and Reorganization	Restructuring and Reorganization—Restructuring and reorganization expenses primarily consist of employee termination costs (including severance, retention, benefits, and payroll taxes) for our mortgage and rentals segments due to the restructuring and reorganization activities from our acquisitions of Bay Equity LLC (“Bay Equity”) and RentPath Holdings, Inc., respectively. These expenses are included in restructuring and reorganization in our consolidated statements of comprehensive loss and in accrued and other liabilities in our consolidated balance sheets. We expect to complete the restructuring and reorganization activities by the end of 2022.
Recently Adopted and Issued Accounting Pronouncements	Recently Adopted Accounting Pronouncements—None applicable.Recently Issued Accounting Pronouncements—On October 28, 2021, the Financial Accounting Standards Board issued ASU 2021-08—Business Combinations (Topic 805): Accounting for Contract Assets and Contract Liabilities from Contracts with Customers, which amends ASC 805 to “require acquiring entities to apply Topic 606 to recognize and measure contract assets and contract liabilities in a business combination.” Under current GAAP, an acquirer generally recognizes such items at fair value on the acquisition date. As a result of the amendments made by ASU 2021-08, it is expected that an acquirer will generally recognize and measure acquired contract assets and contract liabilities in a manner consistent with how the acquiree recognized and measured them in its pre-acquisition financial statements. The amendments made by ASU 2021-08 are effective for fiscal years beginning after December 15, 2022, including interim periods within those fiscal years. Early adoption is permitted, including in interim periods, for any financial statements that have not yet been issued. We elected to early adopt this standard in the second quarter of 2022, and we do not expect any material impact on our financial statements as a result of adopting ASU 2021-08.

Summary of Accounting Policies (Policies)

3 Months Ended

Mar. 31, 2022

Organization, Consolidation and Presentation of Financial Statements [Abstract]

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, 2021 that is included in this quarterly report is derived from the audited consolidated financial statements and notes for the year ended December 31, 2021 included in Item 8 in our annual report for the year ended December 31, 2021. 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, 2022, our statements of comprehensive loss, and statements of changes in mezzanine equity and stockholders’ equity for the three months ended March 31, 2022 and 2021, as well as our statements of cash flows for the three months ended March 31, 2022 and 2021. The results for the three months ended March 31, 2022 are not necessarily indicative of the results to be expected for the year ending December 31, 2022 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 Corporation and its wholly owned subsidiaries, including those entities in which we have a variable interest and of which we are the primary beneficiary. Intercompany transactions and balances have been eliminated.

Use of Estimates

Use of Estimates—The preparation of consolidated financial statements, in conformity with GAAP, requires our management to make estimates and assumptions that affect the reported amounts of assets and liabilities and results of operations during the respective periods. Our estimates include, but are not limited to, valuation of deferred income taxes, stock-based compensation, net realizable value of inventory, capitalization of website and software development costs, the incremental borrowing rate for the determination of the present value of lease payments, recoverability of intangible assets with finite lives, fair value of our mortgage loans held for sale, estimated useful life of intangible assets, fair value of reporting units for purposes of allocating and evaluating goodwill for impairment, and current expected credit losses on certain financial assets. 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.

Restructuring and Reorganization

Restructuring and Reorganization—Restructuring and reorganization expenses primarily consist of employee termination costs (including severance, retention, benefits, and payroll taxes) for our mortgage and rentals segments due to the restructuring and reorganization activities from our acquisitions of Bay Equity LLC (“Bay Equity”) and RentPath Holdings, Inc., respectively. These expenses are included in restructuring and reorganization in our consolidated statements of comprehensive loss and in accrued and other liabilities in our consolidated balance sheets. We expect to complete the restructuring and reorganization activities by the end of 2022.

Recently Adopted and Issued Accounting Pronouncements

Recently Adopted Accounting Pronouncements—None applicable.Recently Issued Accounting Pronouncements—On October 28, 2021, the Financial Accounting Standards Board issued ASU 2021-08—Business Combinations (Topic 805): Accounting for Contract Assets and Contract Liabilities from Contracts with Customers, which amends ASC 805 to “require acquiring entities to apply Topic 606 to recognize and measure contract assets and contract liabilities in a business combination.” Under current GAAP, an acquirer generally recognizes such items at fair value on the acquisition date. As a result of the amendments made by ASU 2021-08, it is expected that an acquirer will generally recognize and measure acquired contract assets and contract liabilities in a manner consistent with how the acquiree recognized and measured them in its pre-acquisition financial statements. The amendments made by ASU 2021-08 are effective for fiscal years beginning after December 15, 2022, including interim periods within those fiscal years. Early adoption is permitted, including in interim periods, for any financial statements that have not yet been issued. We elected to early adopt this standard in the second quarter of 2022, and we do not expect any material impact on our financial statements as a result of adopting ASU 2021-08.