Basis of Presentation	12 Months Ended
Dec. 31, 2015
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The consolidated financial statements presented herein are at December 31, 2015 and December 31, 2014, and for the years ended December 31, 2015, 2014, and 2013. These consolidated financial statements have been 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”) — and the rules and regulations of the Securities and Exchange Commission ("SEC"). In the opinion of management, all normal and recurring adjustments to present fairly the financial condition of the company at December 31, 2015 and results of operations for all periods presented have been made. 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 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 II, Item 7, Management’s Discussion and Analysis of Financial Condition and Results of Operations in this Annual Report on Form 10-K. Additionally, beginning in the second quarter of 2015, we combined our “Mortgage banking activities” and “Other market valuation adjustments” line items on our consolidated statements of income into a single line, now called “Mortgage banking and investment activities, net.” During 2015, we managed our market interest rate risk on the remainder of our assets (excluding MSRs) on a net basis, and we believe that combining these two line items better reflects the net effect of our hedging activities on the assets associated with derivatives that are marked-to-market each quarter. We have conformed the presentation of prior periods related to this change for consistency of comparison. 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, as well as an entity formed in connection with a commercial securitization we engaged in during 2012 (“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 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 record 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 December 31, 2015 and December 31, 2014, and for the years ended December 31, 2015, 2014, and 2013. These consolidated financial statements have been 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”) — and the rules and regulations of the Securities and Exchange Commission ("SEC"). In the opinion of management, all normal and recurring adjustments to present fairly the financial condition of the company at December 31, 2015 and results of operations for all periods presented have been made.

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 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 II, Item 7, Management’s Discussion and Analysis of Financial Condition and Results of Operations in this Annual Report on Form 10-K.

Additionally, beginning in the second quarter of 2015, we combined our “Mortgage banking activities” and “Other market valuation adjustments” line items on our consolidated statements of income into a single line, now called “Mortgage banking and investment activities, net.” During 2015, we managed our market interest rate risk on the remainder of our assets (excluding MSRs) on a net basis, and we believe that combining these two line items better reflects the net effect of our hedging activities on the assets associated with derivatives that are marked-to-market each quarter. We have conformed the presentation of prior periods related to this change for consistency of comparison.

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, as well as an entity formed in connection with a commercial securitization we engaged in during 2012 (“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 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 record 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.