Basis of Presentation	9 Months Ended
Sep. 30, 2016
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The consolidated financial statements presented herein are at September 30, 2016 and December 31, 2015, and for the three and nine months ended September 30, 2016 and 2015. These interim unaudited consolidated financial statements have been prepared in accordance with the rules and regulations of the Securities and Exchange Commission ("SEC"). Certain information and note disclosures normally included in financial statements prepared in accordance with U.S. generally accepted accounting principles ("GAAP") — as prescribed by the Financial Accounting Standards Board’s (“FASB”) Accounting Standards Codification (“ASC”) — have been condensed or omitted according to these SEC rules and regulations. Management believes that the disclosures included in these interim financial statements should be read in conjunction with consolidated financial statements and notes thereto included in the company's Annual Report on Form 10-K for the year ended December 31, 2015. In the opinion of management, all normal and recurring adjustments to present fairly the financial condition of the company at September 30, 2016 and results of operations for all periods presented have been made. The results of operations for the three and nine months ended September 30, 2016 should not be construed as indicative of the results to be expected for the full year. In the second quarter of 2015, we began to specifically identify derivatives that are used to hedge our exposure to market interest rate risk associated with our mortgage servicing right ("MSR") investments. As a result, beginning in the second quarter of 2015, we changed our income statement presentation to include the change in market value of these derivatives in the line item “Mortgage servicing rights income (loss), net.” As we previously managed our market interest rate risk on a portfolio-wide basis and did not necessarily rely on derivatives to hedge our MSRs, we cannot conform prior periods to the current presentation. Therefore, in periods prior to the second quarter of 2015 presented in our consolidated statements of income, amounts in “Mortgage servicing rights income (loss), net” do not reflect the impact of hedging. These changes and year-over-year comparisons are discussed in further detail in Part I, Item 2, Management’s Discussion and Analysis of Financial Condition and Results of Operations in this Quarterly Report on Form 10-Q. Additionally, in the first quarter of 2016, we began to present the changes in fair value of certain investments and their associated derivatives in the new line item "Investment fair value changes, net" on our consolidated statements of income and began to present income from mortgage banking activities in "Mortgage banking activities, net" on our consolidated statements of income. We conformed the presentation of prior periods related to this change for consistency of comparison. See Notes 18 and 19 for additional detail on the components of these income statement line items. Principles of Consolidation In accordance with GAAP, we determine whether we must consolidate transferred financial assets and variable interest entities (“VIEs”) for financial reporting purposes. We currently consolidate the assets and liabilities of certain Sequoia securitization entities where we maintain an ongoing involvement. From its creation in 2012 through the second quarter of 2016, when the third party financing was repaid, we consolidated the assets and liabilities of an entity formed in connection with a commercial securitization we engaged in (“Commercial Securitization”). We also consolidated the assets and liabilities of an entity formed in connection with a resecuritization transaction we engaged in (“Residential Resecuritization”) from its creation in 2011 through the fourth quarter of 2015, when the debt of the entity was repaid, the assets of the entity were distributed to us, and the entity was dissolved. Each securitization entity is independent of Redwood and of each other and the assets and liabilities are not owned by and are not legal obligations of Redwood Trust, Inc. Our exposure to these entities is primarily through the financial interests we have retained, although we are exposed to certain financial risks associated with our role as a sponsor, manager, or depositor of these entities or as a result of our having sold assets directly or indirectly to these entities. For financial reporting purposes, the underlying loans and securities owned at the consolidated Sequoia entities, the Residential Resecuritization entity, and the Commercial Securitization entity are shown under residential and commercial loans and real estate securities on our consolidated balance sheets. The asset-backed securities (“ABS”) issued to third parties by these entities are shown under ABS issued. In our consolidated statements of income, we recorded interest income on the loans and securities owned at these entities and interest expense on the ABS issued by these entities as well as other income and expenses associated with these entities' activities. See Note 4 for further discussion on principles of consolidation. Use of Estimates The preparation of financial statements requires us to make a number of significant estimates. These include estimates of fair value of certain assets and liabilities, amounts and timing of credit losses, prepayment rates, and other estimates that affect the reported amounts of certain assets and liabilities as of the date of the consolidated financial statements and the reported amounts of certain revenues and expenses during the reported periods. It is likely that changes in these estimates (e.g., valuation changes due to supply and demand, credit performance, prepayments, interest rates, or other reasons) will occur in the near term. Our estimates are inherently subjective in nature and actual results could differ from our estimates and the differences could be material.

Basis of Presentation

The consolidated financial statements presented herein are at September 30, 2016 and December 31, 2015, and for the three and nine months ended September 30, 2016 and 2015. These interim unaudited consolidated financial statements have been prepared in accordance with the rules and regulations of the Securities and Exchange Commission ("SEC"). Certain information and note disclosures normally included in financial statements prepared in accordance with U.S. generally accepted accounting principles ("GAAP") — as prescribed by the Financial Accounting Standards Board’s (“FASB”) Accounting Standards Codification (“ASC”) — have been condensed or omitted according to these SEC rules and regulations. Management believes that the disclosures included in these interim financial statements should be read in conjunction with consolidated financial statements and notes thereto included in the company's Annual Report on Form 10-K for the year ended December 31, 2015. In the opinion of management, all normal and recurring adjustments to present fairly the financial condition of the company at September 30, 2016 and results of operations for all periods presented have been made. The results of operations for the three and nine months ended September 30, 2016 should not be construed as indicative of the results to be expected for the full year.

In the second quarter of 2015, we began to specifically identify derivatives that are used to hedge our exposure to market interest rate risk associated with our mortgage servicing right ("MSR") investments. As a result, beginning in the second quarter of 2015, we changed our income statement presentation to include the change in market value of these derivatives in the line item “Mortgage servicing rights income (loss), net.” As we previously managed our market interest rate risk on a portfolio-wide basis and did not necessarily rely on derivatives to hedge our MSRs, we cannot conform prior periods to the current presentation. Therefore, in periods prior to the second quarter of 2015 presented in our consolidated statements of income, amounts in “Mortgage servicing rights income (loss), net” do not reflect the impact of hedging. These changes and year-over-year comparisons are discussed in further detail in Part I, Item 2, Management’s Discussion and Analysis of Financial Condition and Results of Operations in this Quarterly Report on Form 10-Q.

Additionally, in the first quarter of 2016, we began to present the changes in fair value of certain investments and their associated derivatives in the new line item "Investment fair value changes, net" on our consolidated statements of income and began to present income from mortgage banking activities in "Mortgage banking activities, net" on our consolidated statements of income. We conformed the presentation of prior periods related to this change for consistency of comparison. See Notes 18 and 19 for additional detail on the components of these income statement line items.

Principles of Consolidation

In accordance with GAAP, we determine whether we must consolidate transferred financial assets and variable interest entities (“VIEs”) for financial reporting purposes. We currently consolidate the assets and liabilities of certain Sequoia securitization entities where we maintain an ongoing involvement. From its creation in 2012 through the second quarter of 2016, when the third party financing was repaid, we consolidated the assets and liabilities of an entity formed in connection with a commercial securitization we engaged in (“Commercial Securitization”). We also consolidated the assets and liabilities of an entity formed in connection with a resecuritization transaction we engaged in (“Residential Resecuritization”) from its creation in 2011 through the fourth quarter of 2015, when the debt of the entity was repaid, the assets of the entity were distributed to us, and the entity was dissolved. Each securitization entity is independent of Redwood and of each other and the assets and liabilities are not owned by and are not legal obligations of Redwood Trust, Inc. Our exposure to these entities is primarily through the financial interests we have retained, although we are exposed to certain financial risks associated with our role as a sponsor, manager, or depositor of these entities or as a result of our having sold assets directly or indirectly to these entities.

For financial reporting purposes, the underlying loans and securities owned at the consolidated Sequoia entities, the Residential Resecuritization entity, and the Commercial Securitization entity are shown under residential and commercial loans and real estate securities on our consolidated balance sheets. The asset-backed securities (“ABS”) issued to third parties by these entities are shown under ABS issued. In our consolidated statements of income, we recorded interest income on the loans and securities owned at these entities and interest expense on the ABS issued by these entities as well as other income and expenses associated with these entities' activities.

See Note 4 for further discussion on principles of consolidation.

Use of Estimates

The preparation of financial statements requires us to make a number of significant estimates. These include estimates of fair value of certain assets and liabilities, amounts and timing of credit losses, prepayment rates, and other estimates that affect the reported amounts of certain assets and liabilities as of the date of the consolidated financial statements and the reported amounts of certain revenues and expenses during the reported periods. It is likely that changes in these estimates (e.g., valuation changes due to supply and demand, credit performance, prepayments, interest rates, or other reasons) will occur in the near term. Our estimates are inherently subjective in nature and actual results could differ from our estimates and the differences could be material.