Accounting Policies [Abstract] Summary of Significant Accounting Policies Significant Accounting Policies [Text Block] Equity [Abstract] Equity Stockholders' Equity Note Disclosure [Text Block] Subsequent Events [Abstract] Subsequent Events Subsequent Events [Text Block] Organization, Consolidation and Presentation of Financial Statements [Abstract] Schedule of Variable Interest Entities [Table] Schedule of Variable Interest Entities [Table] Related Party [Axis] Related Party [Axis] Related Party [Domain] Related Party [Domain] Legacy Sequoia Legacy Sequoia Securitization Entities [Member] Legacy Sequoia Securitization Entities [Member] Sequoia Choice Sequoia Choice Securitization Entities [Member] Sequoia Choice Securitization Entities [Member] Freddie Mac SLST Freddie Mac SLST [Member] Freddie Mac SLST [Member] Freddie Mac K-Series Freddie Mac K-Series Securitization Entities [Member] Freddie Mac K-Series Securitization Entities [Member] Servicing Investment Excess Servicing Entities [Member] Excess Servicing Entities [Member] Variable Interest Entities [Axis] Variable Interest Entities [Axis] Variable Interest Entity, Classification [Domain] Variable Interest Entity, Classification [Domain] Variable Interest Entity, Primary Beneficiary Variable Interest Entity, Primary Beneficiary [Member] Variable Interest Entity, Not Primary Beneficiary Variable Interest Entity, Not Primary Beneficiary [Member] Variable Interest Entity [Line Items] Variable Interest Entity [Line Items] Estimated fair value of investments Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net Number of partnerships consolidated Number Of Partnerships Consolidated Number Of Partnerships Consolidated VIE, ownership interest rate Variable Interest Entity, Qualitative or Quantitative Information, Ownership Percentage MSRs Servicing Asset at Fair Value, Amount Number of securitization entities to which asset transferred (in entities) Number of Securitization Entities to which Asset Transferred Number of Securitization Entities to which Asset Transferred Gain (loss) on securitization of financial assets Gain (Loss) on Securitization of Financial Assets Loan acquisition, aggregate amount acquired Loan Acquisition, Aggregate Amount Acquired Loan Acquisition, Aggregate Amount Acquired Receivables [Abstract] SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate Schedule [Table] SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate Schedule [Table] Class of Financing Receivable [Axis] Class of Financing Receivable [Axis] Class of Financing Receivable [Domain] Class of Financing Receivable [Domain] Held-for-investment at fair value Residential Loans Held For Investment At Fair Value [Member] Residential Loans Held For Investment At Fair Value [Member] Legal Entity [Axis] Legal Entity [Axis] Entity [Domain] Entity [Domain] Redwood Redwood Trust Inc. [Member] Redwood Trust Inc. [Member] Financial Asset, Period Past Due [Axis] Financial Asset, Period Past Due [Axis] Financial Asset, Period Past Due [Domain] Financial Asset, Period Past Due [Domain] Financing Receivables, Equal to Greater than 90 Days Past Due Financial Asset, Equal to or Greater than 90 Days Past Due [Member] Financial Instrument [Axis] Financial Instrument [Axis] Financial Instruments [Domain] Financial Instruments [Domain] Multifamily loans, held-for-investment, at fair value Multifamily Loans [Member] Multifamily Loans [Member] Statistical Measurement [Axis] Statistical Measurement [Axis] Statistical Measurement [Domain] Statistical Measurement [Domain] Minimum Minimum [Member] Maximum Maximum [Member] SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items] SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items] Number of loans SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Number of Loans Loan principal Principal Amount Outstanding on Loans Managed and Securitized or Asset-backed Financing Arrangement Amount of loans in foreclosure Delinquent Amount at End of Period on Loans Managed and Securitized or Asset-backed Financing Arrangement Loans, at fair value Loans and Leases Receivable, Net Amount Weighted average maturity (in years) Debt Instrument, Term Weighted average original loan-to-value (LTV) Financing Receivable, Loan To Value Ratio Financing Receivable, Loan To Value Ratio Weighted average coupon rate Financing Receivables, Weighted Average Interest Rate Financing Receivables, Weighted Average Interest Rate Contract maturities Financing Receivable, Contract Maturities Financing Receivable, Contract Maturities Number of loans past due Financing Receivable, Number Of Loans Past Due Financing Receivable, Number Of Loans Past Due Number of loans in foreclosure Financing Receivable, Number Of Loans In Foreclosure Financing Receivable, Number Of Loans In Foreclosure Valuation adjustment gain (loss) SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Period Increase (Decrease) Number of operating segments Number of Operating Segments Commitments and Contingencies Disclosure [Abstract] 2019 (3 months) Lessee, Operating Lease, Liability, Payments, Remainder of Fiscal Year 2020 Lessee, Operating Lease, Liability, Payments, Due Year Two 2021 Lessee, Operating Lease, Liability, Payments, Due Year Three 2022 Lessee, Operating Lease, Liability, Payments, Due Year Four 2023 and thereafter Lessee, Operating Lease, Liability, Payments, Due In Five Years And Thereafter Lessee, Operating Lease, Liability, Payments, Due In Five Years And Thereafter Total Lease Commitments Lessee, Operating Lease, Liability, Payments, Due Less: Imputed interest Lessee, Operating Lease, Liability, Undiscounted Excess Amount Lease liability Operating Lease, Liability Schedule of Goodwill [Table] Schedule of Goodwill [Table] Business Acquisition [Axis] Business Acquisition [Axis] Business Acquisition, Acquiree [Domain] Business Acquisition, Acquiree [Domain] 5 Arches, LLC 5 Arches, LLC [Member] 5 Arches, LLC [Member] Goodwill [Line Items] Goodwill [Line Items] Goodwill [Roll Forward] Goodwill [Roll Forward] Beginning balance Goodwill Goodwill recognized from 5 Arches acquisition Goodwill, Acquired During Period Measurement period adjustment Goodwill, Purchase Accounting Adjustments Impairment Goodwill, Impairment Loss Ending Balance Income Tax Disclosure [Abstract] Reconciliation of Statutory Tax Rate to Effective Tax Rate Schedule of Effective Income Tax Rate Reconciliation [Table Text Block] Debt Disclosure [Abstract] Short-Term Debt Facilities Schedule of Short-term Debt [Table Text Block] Short-Term Debt by Collateral Type and Remaining Maturities Schedule of Maturities of Debt Disclosure [Table Text Block] Schedule of Maturities of Debt Disclosure. Investments, Debt and Equity Securities [Abstract] Real Estate Securities Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block] Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract] Other Assets and Other Liabilities [Table] Other Assets and Other Liabilities [Table] Other Assets and Other Liabilities [Table] Short-term Debt, Type [Axis] Short-term Debt, Type [Axis] Short-term Debt, Type [Domain] Short-term Debt, Type [Domain] Bridge Loan Bridge Loan [Member] Investment Type [Axis] Investment Type [Axis] Investments [Domain] Investments [Domain] Debt Securities Debt Securities [Member] Other Assets and Other Liabilities [Line Items] Other Assets and Other Liabilities [Line Items] Other Assets and Other Liabilities [Line Items] Real estate owned (REO) Real Estate Acquired Through Foreclosure Amount related to transfers into REO SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Acquisition Through Foreclosure REO liquidations SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Cost of Investment in Real Estate Sold Unrealized gain resulting from market valuation adjustments on REO Principal Investment Gain (Loss) Number of REO properties recorded on balance sheet Number of Real Estate Properties Payable to minority partner Noncontrolling Interest in Limited Partnerships Net gain allocated to Limited Partners Net Income (Loss) Allocated to Limited Partners Statement of Financial Position [Abstract] Statement [Table] Statement [Table] Residential loans, held-for-sale, at fair value Residential Loans Held For Sale [Member] Residential Loans Held For Sale [Member] Residential loans, held-for-investment, at fair value Residential Loans Held For Investment At Fair Value, Including Loans At Historical Cost [Member] Residential Loans Held For Investment At Fair Value, Including Loans At Historical Cost [Member] Business purpose residential loans, at fair value Business Purpose Residential Loans [Member] Business Purpose Residential Loans [Member] Statement [Line Items] Statement [Line Items] ASSETS Assets [Abstract] Real estate securities, at fair value Marketable Securities Other investments Other Investments Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Restricted cash Restricted Cash and Cash Equivalents Goodwill and intangible assets Intangible Assets, Net (Including Goodwill) Accrued interest receivable Interest Receivable Derivative assets Derivative Asset Other assets Other Assets Total Assets Assets LIABILITIES AND EQUITY Liabilities and Equity [Abstract] Liabilities Liabilities [Abstract] Short-term debt, net Short-term Debt Accrued interest payable Interest Payable Derivative liabilities Derivative Liability Accrued expenses and other liabilities Accrued Liabilities Asset-backed securities issued, at fair value Secured Debt Long-term debt, net Long-term Debt Total liabilities Liabilities Commitments and Contingencies (see Note 16) Commitments and Contingencies Equity Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest [Abstract] Common stock, par value $0.01 per share, 270,000,000 and 180,000,000 shares authorized; 112,101,731 and 84,884,344 issued and outstanding Common Stock, Value, Issued Additional paid-in capital Additional Paid in Capital, Common Stock Accumulated other comprehensive income Accumulated Other Comprehensive Income (Loss), Net of Tax Cumulative earnings Retained Earnings (Accumulated Deficit) Cumulative distributions to stockholders Cumulative Dividends Total equity Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Total Liabilities and Equity Liabilities and Equity Fair Value Disclosures [Abstract] Fair Value, Recurring and Nonrecurring [Table] Fair Value, Recurring and Nonrecurring [Table] Measurement Frequency [Axis] Measurement Frequency [Axis] Measurement Frequency [Domain] Measurement Frequency [Domain] Fair Value, Measurements, Recurring Fair Value, Recurring [Member] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] Level 1 Fair Value, Inputs, Level 1 [Member] Level 2 Fair Value, Inputs, Level 2 [Member] Level 3 Fair Value, Inputs, Level 3 [Member] Residential Loans Residential Loans at Fair Value [Member] Residential Loans at Fair Value [Member] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Assets Assets, Fair Value Disclosure [Abstract] Residential loans Receivables, Fair Value Disclosure Business purpose residential loans Business Purpose Loans, Fair Value Disclosure Business Purpose Loans, Fair Value Disclosure Multifamily loans Multifamily Loans, Fair Value Disclosure Multifamily Loans, Fair Value Disclosure Trading securities Debt Securities, Trading, and Equity Securities, FV-NI Available-for-sale securities Debt Securities, Available-for-sale Servicer advance investments Servicer Advance Investments Servicer Advance Investments Excess MSRs Excess Mortgage Servicing Rights, IOs Excess Mortgage Servicing Rights, IOs Shared home appreciation options Home Appreciation Options, Fair value Disclosure Home Appreciation Options, Fair value Disclosure Pledged collateral Pledged Assets Separately Reported, Other Assets Pledged as Collateral, at Fair Value FHLBC stock Investment in Federal Home Loan Bank Stock, Fair Value Disclosure Guarantee asset Guarantees Asset, Fair Value Disclosure Guarantees Asset, Fair Value Disclosure Liabilities Liabilities, Fair Value Disclosure [Abstract] Contingent consideration Business Combination, Contingent Consideration, Liability ABS issued Debt Instrument, Fair Value Disclosure Mortgage Banking [Abstract] Residential Mortgage Banking Activities, Net Residential Mortgage Banking Activities [Member] Residential Mortgage Banking Activities [Member] Business Purpose Mortgage Banking Activities, Net Business Purpose Mortgage Banking [Member] Business Purpose Mortgage Banking [Member] Asset Class [Axis] Asset Class [Axis] Asset Class [Domain] Asset Class [Domain] Residential loans, at fair value Risk management derivatives Price Risk Derivative [Member] Single-family rental loans, at fair value Single-Family Rental Loans, Held-For-Sale At Fair Value [Member] Single-Family Rental Loans, Held-For-Sale At Fair Value [Member] Changes in fair value of assets Increase (Decrease) in Fair Value Adjustments on Assets Increase (Decrease) in Fair Value Adjustments on Assets Risk management derivatives Increase (Decrease) in Fair Value of Price Risk Fair Value Hedging Instruments Other income, net Other Income Mortgage banking activities, net Mortgage Banking Activities, Net The net income attributable to mortgage banking activities. This includes market valuations related to residential and commercial loans, Sequoia IOs, and mortgage banking derivatives, as well as realized gains or losses associated with mortgage loan sales. Schedule of Assets Acquired and Liabilities Assumed Schedule of Recognized Identified Assets Acquired and Liabilities Assumed [Table Text Block] Schedule of Finite-Lived Intangible Assets Schedule of Finite-Lived Intangible Assets Acquired as Part of Business Combination [Table Text Block] Finite-lived Intangible Assets Amortization Expense Finite-lived Intangible Assets Amortization Expense [Table Text Block] Schedule of Goodwill Schedule of Goodwill [Table Text Block] Pro Forma Information Business Acquisition, Pro Forma Information [Table Text Block] Schedule of Long-term Debt Instruments [Table] Schedule of Long-term Debt Instruments [Table] Debt Instrument [Axis] Debt Instrument [Axis] Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Asset-backed securities issued Asset-backed Securities [Member] Certificates with principal balance Certificates With Principal Value [Member] Certificates With Principal Value [Member] Interest-only certificates Interest Only Certificates [Member] Interest Only Certificates [Member] Debt Instrument [Line Items] Debt Instrument [Line Items] Certificates Long-term Debt, Gross Market valuation adjustments New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets Total FHLBC Borrowings Range of weighted average interest rates, by series Debt, Weighted Average Interest Rate Number of series Number of Series Number of Series Business purpose residential loans Multifamily loans Trading securities Trading Securities1 [Member] Trading Securities [Member] Available-for-sale securities Available-for-sale Securities [Member] Servicer advance investments Servicer Advance Investments [Member] Servicer Advance Investments [Member] MSRs Mortgage Servicing Rights [Member] Mortgage Servicing Rights [Member] Excess MSRs Excess Mortgage Servicing Rights [Member] Excess Mortgage Servicing Rights [Member] Loan purchase commitments Loan Purchase Commitments [Member] Other assets - Guarantee asset Asset Value Guarantees [Member] Asset Value Guarantees [Member] Home appreciation options Home Appreciation Option [Member] Home Appreciation Option [Member] Investment, Name [Axis] Investment, Name [Axis] Investment, Name [Domain] Investment, Name [Domain] Residential loans at Redwood Residential Loans Held At Redwood [Member] Residential Loans Held At Redwood [Member] Residential loans at consolidated Sequoia entities Residential Loans At Consolidated Sequoia Entities [Member] Residential Loans At Consolidated Sequoia Entities [Member] Liability Class [Axis] Liability Class [Axis] Fair Value by Liability Class [Domain] Fair Value by Liability Class [Domain] Contingent Consideration Contingent Consideration [Member] Contingent Consideration [Member] ABS Issued Net gains (losses) attributable to level 3 assets still held included in net income Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included In Earnings, Excluding Sold, Matured, Called, Or Written Down Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included In Earnings, Excluding Sold, Matured, Called, Or Written Down Net gains (losses) attributable to level 3 liabilities still held included in net income Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included In Earnings, Excluding Sold, Matured, Called, Or Written Down Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included In Earnings, Excluding Sold, Matured, Called, Or Written Down Derivative Instruments and Hedging Activities Disclosure [Abstract] Derivative Financial Instruments Derivative Instruments and Hedging Activities Disclosure [Text Block] Provision for income taxes Income Tax Expense (Benefit) Classifications and Carrying Value of Loans Carrying Value Of Loans [Table Text Block] Tabular disclosure of the net carrying value for loans by entity as of the balance sheet date. Common stock, par value (usd per share) Common Stock, Par or Stated Value Per Share Common stock, shares authorized (shares) Common Stock, Shares Authorized Common stock, issued (shares) Common Stock, Shares, Issued Common stock, outstanding (shares) Common Stock, Shares, Outstanding Variable interest held by entity, assets Variable Interest Entity, Consolidated, Carrying Amount, Assets Variable interest held by entity, liabilities Variable Interest Entity, Consolidated, Carrying Amount, Liabilities Convertible notes Convertible Notes Payable, Current Total Business Purpose Residential Loans Single-Family Rental, Held-for-sale at fair value Residential Bridge, Held-for-sale at fair value Residential Bridge Held For Sale At Fair Value [Member] Residential Bridge Held For Sale At Fair Value [Member] Held-for-sale at fair value, Total Loans Held For Sale At Fair Value [Member] Loans Held For Sale At Fair Value [Member] Single-Family Rental, Held-for-investment at fair value Single Family Rental Loans Held For Investment At Fair Value [Member] Single Family Rental Loans Held For Investment At Fair Value [Member] Residential Bridge, Held-for-investment at fair value Residential Bridge Loans Held-For-Investment [Member] Residential Bridge Loans Held-for-investment [Member] Held-for-investment at fair value, Total Loans Held For Investment At Fair Value [Member] Loans Held For Investment At Fair Value [Member] Total of single family rental Single Family Rental Loans [Member] Single Family Rental Loans Total residential bridge loans Residential Bridge Loans [Member] Residential Bridge Loans [Member] Other Commitments [Axis] Other Commitments [Axis] Other Commitments [Domain] Other Commitments [Domain] Commitment To Fund Residential Bridge Loan Commitment To Fund Residential Bridge Loan [Member] Commitment To Fund Residential Bridge Loan [Member] Proceeds from loan originations Proceeds from Loan Originations, Including To Related Parties Proceeds from Loan Originations, Including To Related Parties Proceeds from loan originations to third parties Proceeds from Loan Originations Market valuations gains and losses, net Fee income Servicing Fees 1 Servicing Fees 1 Purchases of held-for-sale loans Payments to Purchase Loans Held-for-sale Proceeds from sales of held-for-sale loans Proceeds from Sale of Loans Held-for-sale Gain (loss) on investments Gain (Loss) on Investments Collateral amounts Debt Instrument, Collateral Amount Weighted-average debt service coverage ratio Financing Receivable, Weighted Average Debt Service Coverage Ratio Financing Receivable, Weighted Average Debt Service Coverage Ratio Transfer from Investments Transfer to Investments Unpaid principal balance on delinquent or foreclosure loans Loans And Leases Receivable, Delinquent Or In Foreclosure Loans And Leases Receivable, Delinquent Or In Foreclosure Loans in foreclosure amount Mortgage Loans in Process of Foreclosure, Amount Number of loans transferred Real Estate Owned, Transfer to Real Estate Owned, Number Of Loans Real Estate Owned, Transfer to Real Estate Owned, Number Of Loans Transfer to REO Real Estate Owned, Transfer to Real Estate Owned Weighted average original Fair Isaac Corporation (FICO) score Financing Receivable, Credit Score, FICO, Weighted Average The weighted average FICO score for borrowers at the time loans were originated. Commitment to fund loan Other Commitment Share-based Payment Arrangement [Abstract] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Plan Name [Axis] Plan Name [Axis] Plan Name [Domain] Plan Name [Domain] Incentive Plans Incentive Plans [Member] Incentive Plans [Member] Employee Stock Purchase Plan Employee Stock Purchase Plan [Member] Employee Stock Purchase Plan [Member] Award Type [Axis] Award Type [Axis] Award Type [Domain] Award Type [Domain] Restricted Stock Awards Restricted Stock [Member] Restricted Stock Units Restricted Stock Units (RSUs) [Member] Deferred Stock Units Deferred Stock Units [Member] Deferred Stock Units [Member] Performance Stock Units Performance Shares [Member] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized [Roll Forward] Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized [Roll Forward] Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized [Roll Forward] Unrecognized compensation cost at beginning of period Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount Equity grants Share-based Payment Arrangement, Amount Capitalized Equity grant forfeitures Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost, Forfeitures Represents the amount of equity grant forfeitures during the period. Equity compensation expense Allocated Share-based Compensation Expense, Including Restructuring Allocated Share-based Compensation Expense, Including Restructuring Unrecognized Compensation Cost at End of Period Statement of Stockholders' Equity [Abstract] Common dividends declared (in dollars per share) Common Stock, Dividends, Per Share, Declared Reclassification out of Accumulated Other Comprehensive Income [Table] Reclassification out of Accumulated Other Comprehensive Income [Table] Reclassification out of Accumulated Other Comprehensive Income [Axis] Reclassification out of Accumulated Other Comprehensive Income [Axis] Reclassification out of Accumulated Other Comprehensive Income [Domain] Reclassification out of Accumulated Other Comprehensive Income [Domain] Reclassification out of Accumulated Other Comprehensive Income Reclassification out of Accumulated Other Comprehensive Income [Member] Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Net Unrealized Gains on Available-for-Sale Securities AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Parent [Member] Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items] Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items] Investment fair value changes, net Unrealized Gain (Loss) on Investments Realized gains, net Realized Investment Gains (Losses) Provision for income taxes Net Income before Provision for Income Taxes Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest Other than temporary impairments Other than Temporary Impairment Losses, Investments Other than temporary impairments recognized in income Other than Temporary Impairment Losses, Investments, Portion in Other Comprehensive Loss, before Tax, Including Portion Attributable to Noncontrolling Interest Other-than-temporary impairment loss portion recognized in earnings Other-than-temporary Impairment Loss, Debt Securities, Portion Recognized in Earnings Changes to Accumulated Other Comprehensive Income by Component Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Reclassifications out of Accumulated Other Comprehensive Income Reclassification out of Accumulated Other Comprehensive Income [Table Text Block] Basic and Diluted Earnings Per Common Share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Long-Term Debt Long-term Debt [Text Block] Investment Fair Value Changes, Net Investments Fair Value Changes, Net [Text Block] Investments Fair Value Changes, Net [Text Block] Business Purpose Residential Loans Loans, Notes, Trade and Other Receivables Disclosure [Text Block] Subsequent Event [Table] Subsequent Event [Table] CoreVest American Finance Lender LLC CoreVest American Finance Lender LLC [Member] CoreVest American Finance Lender LLC [Member] Subsequent Event Type [Axis] Subsequent Event Type [Axis] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Subsequent Event Subsequent Event [Member] Subsequent Event [Line Items] Subsequent Event [Line Items] Percent acquired Business Acquisition, Percentage of Voting Interests Acquired Total consideration Business Combination, Consideration Transferred Investment Holdings [Table] Investment Holdings [Table] Senior IO Securities Senior Securities [Member] Senior Securities [Member] Subordinate Securities Subordinate Securities [Member] Subordinate Securities [Member] Mezzanine Real Estate Securities, Prime Mezzanine [Member] Real Estate Securities, Prime Mezzanine [Member] Subordinate Real Estate Securities, Prime Subordinate [Member] Real Estate Securities, Prime Subordinate [Member] Investment Holdings [Line Items] Investment Holdings [Line Items] Schedule of Short-term Debt [Table] Schedule of Short-term Debt [Table] Servicer advance financing Servicer Advance Financing [Member] Servicer Advance Financing [Member] Facilities Line of Credit [Member] Convertible notes, net Convertible Notes Payable [Member] Residential loan warehouse Residential Loan Warehouse [Member] Residential Loan Warehouse [Member] Real estate securities repo Real Estate Securities Repo [Member] Real Estate Securities Repo [Member] Single-family rental loan warehouse Single-Family Rental Loan Warehouse Facilities [Member] Single-Family Rental Loan Warehouse Facilities [Member] Residential bridge loan warehouse Residential Bridge Loan Warehouse Facilities [Member] Residential Bridge Loan Warehouse Facilities [Member] Business purpose loan working capital Business Purpose Working Capital [Member] Business Purpose Working Capital [Member] Short-term Debt [Line Items] Short-term Debt [Line Items] Number of Facilities Number of Facilities Number of Facilities Outstanding Balance Limit Line of Credit Facility, Maximum Borrowing Capacity Weighted Average Interest Rate Short-term Debt, Weighted Average Interest Rate, at Point in Time Weighted Average Days Until Maturity Debt Instrument Average, Maturity Term Debt Instrument Average, Maturity Term Financial Instruments Owned and Pledged as Collateral [Table] Financial Instruments Owned and Pledged as Collateral [Table] Residential loans Residential Loans [Member] Residential Loans [Member] Restricted cash Cash and Cash Equivalents [Domain] Accrued interest receivable Interest Receivable [Member] Interest Receivable [Member] REO Other Real Estate Owned [Member] Other Real Estate Owned [Member] Financial Instruments Owned and Pledged as Collateral [Line Items] Financial Instruments Owned and Pledged as Collateral [Line Items] Collateral for ABS Issued Collateral for Asset Backed Securities Issued The carrying value of collateral as of the balance sheet date for the asset-backed securities issued. Schedule of Finite-Lived Intangible Assets [Table] Schedule of Finite-Lived Intangible Assets [Table] Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets, Major Class Name [Domain] Finite-Lived Intangible Assets, Major Class Name [Domain] Broker network Broker Network [Member] Broker Network [Member] Non-compete agreements Noncompete Agreements [Member] Loan administration fees on existing loan assets Management Fee On Existing Assets Under Management [Member] Management Fee On Existing Assets Under Management [Member] Tradename Trade Names [Member] Finite-Lived Intangible Assets [Line Items] Finite-Lived Intangible Assets [Line Items] Finite-lived Intangible Assets [Roll Forward] Finite-lived Intangible Assets [Roll Forward] Carrying Value at December 31, 2018 Finite-Lived Intangible Assets, Net Additions Finite-lived Intangible Assets Acquired Amortization Expense Amortization of Intangible Assets Carrying Value at September 30, 2019 Weighted Average Amortization Period (in years) Finite-Lived Intangible Asset, Useful Life Segment Reporting [Abstract] Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Consolidation Items [Axis] Consolidation Items [Axis] Consolidation Items [Domain] Consolidation Items [Domain] Corporate/ Other Corporate, Non-Segment [Member] Subsegments [Axis] Subsegments [Axis] Subsegments [Domain] Subsegments [Domain] Legacy Consolidated VIEs Legacy Consolidated Variable Interest Entities [Member] Legacy Consolidated Variable Interest Entities [Member] Other Other Subsegments [Member] Other Subsegments [Member] Segment Reporting Information [Line Items] Segment Reporting Information [Line Items] Interest income Interest and Dividend Income, Operating Interest expense Interest Expense Net Interest Income Interest Income (Expense), Net Investment fair value changes, net Other income Other Nonoperating Income (Expense) Total non-interest income, net Noninterest Income Direct operating expenses Operating Expenses Net Income Net Income (Loss) Attributable to Parent Amortization of debt issuance costs Amortization of Debt Issuance Costs Basic Earnings per Common Share: Earnings Per Share, Basic [Abstract] Net income attributable to Redwood Less: Dividends and undistributed earnings allocated to participating securities Participating Securities, Distributed and Undistributed Earnings (Loss), Basic Net income allocated to common shareholders Net Income (Loss) Available to Common Stockholders, Basic Basic weighted average common shares outstanding (in shares) Weighted Average Number of Shares Outstanding, Basic Basic Earnings per Common Share (in dollars per share) Earnings Per Share, Basic Diluted Earnings per Common Share: Earnings Per Share, Diluted [Abstract] Less: Dividends and undistributed earnings allocated to participating securities Participating Securities, Distributed and Undistributed Earnings (Loss), Diluted Add back: Interest expense on convertible notes for the period, net of tax Interest on Convertible Debt, Net of Tax Net income allocated to common shareholders Net Income (Loss) Available to Common Stockholders, Diluted Weighted average common shares outstanding (in shares) Net effect of dilutive equity awards (in shares) Weighted Average Number Diluted Shares Outstanding Adjustment Net effect of assumed convertible notes conversion to common shares (in shares) Incremental Common Shares Attributable to Dilutive Effect of Conversion of Debt Securities Diluted weighted average common shares outstanding (in shares) Weighted Average Number of Shares Outstanding, Diluted Diluted Earnings per Common Share (in dollars per share) Earnings Per Share, Diluted Equity Compensation Plans Share-based Payment Arrangement [Text Block] Statement of Comprehensive Income [Abstract] Net Income Other comprehensive loss: Other Comprehensive Income (Loss), Net of Tax [Abstract] Net unrealized gain (loss) on available-for-sale securities Other Comprehensive Income (Loss), Securities, Available-for-sale, Adjustment, after Tax Reclassification of unrealized gain on available-for-sale securities to net income Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Net of Tax Net unrealized (loss) gain on interest rate agreements Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax, Parent Net unrealized (loss) gain on interest rate agreements Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax Total other comprehensive loss Other Comprehensive Income (Loss), Net of Tax Total Comprehensive Income Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Schedule of Sensitivity Analysis of Fair Value, Transferor's Interests in Transferred Financial Assets [Table] Schedule of Sensitivity Analysis of Fair Value, Transferor's Interests in Transferred Financial Assets [Table] Senior Securities Sensitivity Analysis of Fair Value of Interests Continued to be Held by Transferor, Servicing Assets or Liabilities, Impact of Adverse Change in Assumption [Line Items] Sensitivity Analysis of Fair Value of Interests Continued to be Held by Transferor, Servicing Assets or Liabilities, Impact of Adverse Change in Assumption [Line Items] Fair value Transferor's Interests in Transferred Financial Assets, Fair Value Expected life (in years) Assumption for Fair Value of Assets or Liabilities that relate to Transferor's Continuing Involvement, Weighted Average Life Prepayment speed assumption (annual CPR) Sensitivity Analysis of Fair Value, Transferor's Interests in Transferred Financial Assets, Impact of Other than 10 or 20 Percent Adverse Change in Prepayment Speed, Percent Decrease in fair value from: Sensitivity Analysis Of Fair Value Of Interests Continued To Be Held By Transferor Servicing Assets Or Liabilities Impact Of Adverse Change In Prepayment Speed [Abstract] Sensitivity Analysis Of Fair Value Of Interests Continued To Be Held By Transferor Servicing Assets Or Liabilities Impact Of Adverse Change In Prepayment Speed [Abstract] 10% adverse change Sensitivity Analysis of Fair Value, Transferor's Interests in Transferred Financial Assets, Impact of 10 Percent Adverse Change in Prepayment Speed 25% adverse change Sensitivity Analysis of Fair Value, Transferor's Interests in Transferred Financial Assets, Impact of Other than 10 or 20 Percent Adverse Change in Prepayment Speed Discount rate assumption Sensitivity Analysis of Fair Value, Transferor's Interests in Transferred Financial Assets, Impact of Other than 10 or 20 Percent Adverse Change in Discount Rate, Percent Decrease in fair value from: Sensitivity Analysis of Fair Value of Interests that Continue to be Held by Transferor, Servicing Assets or Liabilities [Abstract] Sensitivity Analysis of Fair Value of Interests that Continue to be Held by Transferor, Servicing Assets or Liabilities [Abstract] 100 basis point increase Sensitivity Analysis of Fair Value, Transferor's Interests in Transferred Financial Assets, Impact of Other than 10 or 20 Percent Adverse Change in Discount Rate 200 basis point increase Sensitivity Analysis of Fair Value of Interests Continued to Be Held by Transferor Servicing Assets or Liabilities Impact of Two Hundred Basis Point Adverse Change in Discount Rate The hypothetical financial impact of a 200 basis point adverse change of the discount rate on the fair value of transferor's interests in transferred financial assets (including any servicing assets or servicing liabilities) as of the balance sheet date. Credit loss assumption Sensitivity Analysis of Fair Value, Transferor's Interests in Transferred Financial Assets, Impact Other than 10 or 20 Percent Adverse Change in Expected Credit Loss, Percent Decrease in fair value from: Sensitivity Analysis Of Fair Value Of Interests Continued To Be Held By Transferor Servicing Assets Or Liabilities Impact Of Adverse Change In Expected Credit Losses [Abstract] Sensitivity Analysis Of Fair Value Of Interests Continued To Be Held By Transferor Servicing Assets Or Liabilities Impact Of Adverse Change In Expected Credit Losses [Abstract] 10% higher losses Sensitivity Analysis of Fair Value, Transferor's Interests in Transferred Financial Assets, Impact of 10 Percent Adverse Change in Expected Credit Losses 25% higher losses Sensitivity Analysis of Fair Value, Transferor's Interests in Transferred Financial Assets, Impact Other than 10 or 20 Percent Adverse Change in Expected Credit Loss Impact of adverse change in prepayment speed Sensitivity Analysis Of Fair Value, Transferor's Interests In Transferred Financial Assets, Impact Of Adverse Change In Prepayment Speed, Percent Sensitivity Analysis Of Fair Value, Transferor's Interests In Transferred Financial Assets, Impact Of Adverse Change In Prepayment Speed, Percent Impact of increase in discount rate assumption Sensitivity Analysis Of Fair Value, Transferor's Interests In Transferred Financial Assets, Impact On Discount Rate Of Basis Point Increase, Percent Sensitivity Analysis Of Fair Value, Transferor's Interests In Transferred Financial Assets, Impact On Discount Rate Of Basis Point Increase, Percent Impact of adverse change in expected credit losses Sensitivity Analysis Of Fair Value, Transferor's Interests In Transferred Financial Assets, Impact Of Adverse Change In Expected Credit Losses, Percent Sensitivity Analysis Of Fair Value, Transferor's Interests In Transferred Financial Assets, Impact Of Adverse Change In Expected Credit Losses, Percent Schedule of Available-for-sale Securities [Table] Schedule of Available-for-sale Securities [Table] Prime Real Estate Securities, Prime [Member] Real Estate Securities, Prime [Member] Debt Securities, Available-for-sale [Line Items] Debt Securities, Available-for-sale [Line Items] Prepayment rates Available For Sale Securities In Unrealized Loss Positions Qualitative Disclosure Prepayment Rates This item represents a significant valuation assumption on prepayment rates, represented as a percentage, which was considered as one of the potential factors in reaching a conclusion that the available-for-sale investments are not other-than-temporarily impaired. Projected losses Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Other, Default Rate Other Assets and Liabilities Other Assets And Other Liabilities Disclosure [Text Block] Other Assets And Other Liabilities Disclosure Offsetting Asset and Liabilities [Table] Offsetting Asset and Liabilities [Table] Offsetting Asset and Liabilities [Table] Interest rate agreements Interest Rate Swap [Member] TBAs TBA Contracts [Member] TBA Contracts [Member] Interest Rate Agreement, TBAs, And Futures Interest Rate Agreement, TBAs, And Futures [Member] Interest Rate Agreement, TBAs, And Futures [Member] Loan warehouse debt Warehouse Agreement Borrowings [Member] Security repurchase agreements Repurchase Agreements [Member] Offsetting Asset and Liabilities [Line Items] Offsetting Asset and Liabilities [Line Items] Offsetting Asset and Liabilities [Line Items] Assets Derivative Asset [Abstract] Gross Amounts of Recognized Assets (Liabilities) Derivative Asset, Fair Value, Gross Asset Gross Amounts Offset in Consolidated Balance Sheet Derivative Asset, Fair Value, Gross Liability Net Amounts of Assets (Liabilities) Presented in Consolidated Balance Sheet Gross Amounts Not Offset in Consolidated Balance Sheet, Financial Instruments Derivative, Collateral, Obligation to Return Securities Gross Amounts Not Offset in Consolidated Balance Sheet, Cash Collateral (Received) Pledged Derivative, Collateral, Obligation to Return Cash Net Amount Derivative Asset, Fair Value, Offset Against Collateral, Net of Not Subject to Master Netting Arrangement, Policy Election Liabilities Derivative Liability [Abstract] Gross Amounts of Recognized Assets (Liabilities) Derivative Liability, Fair Value, Gross Liability Gross Amounts Offset in Consolidated Balance Sheet Derivative Liability, Fair Value, Gross Asset Net Amounts of Assets (Liabilities) Presented in Consolidated Balance Sheet Gross Amounts Not Offset in Consolidated Balance Sheet, Financial Instruments Derivative, Collateral, Right to Reclaim Securities Gross Amounts Not Offset in Consolidated Balance Sheet, Cash Collateral (Received) Pledged Derivative, Collateral, Right to Reclaim Cash Net Amount Derivative Liability, Fair Value, Offset Against Collateral, Net of Not Subject to Master Netting Arrangement, Policy Election Loan warehouse debt and Security repurchase agreement Securities Sold under Agreements to Repurchase, Gross Including Not Subject to Master Netting Arrangement [Abstract] Gross Amounts of Recognized Assets (Liabilities) Securities Sold under Agreements to Repurchase, Gross Gross Amounts Offset in Consolidated Balance Sheet Securities Sold under Agreements to Repurchase, Asset Net Amounts of Assets (Liabilities) Presented in Consolidated Balance Sheet Securities Sold under Agreements to Repurchase Gross Amounts Not Offset in Consolidated Balance Sheet, Financial Instruments Securities Sold under Agreements to Repurchase, Collateral, Right to Reclaim Securities Gross Amounts Not Offset in Consolidated Balance Sheet, Cash Collateral (Received) Pledged Securities Sold under Agreements to Repurchase, Collateral, Right to Reclaim Cash Net Amount Securities Sold under Agreements to Repurchase, Amount Offset Against Collateral Total Liabilities Derivative Liability, Securities Sold under Agreements to Repurchase, Securities Loaned, Gross Including Not Subject to Master Netting Arrangement [Abstract] Gross Amounts of Recognized Assets (Liabilities) Derivative Liability, Securities Sold under Agreements to Repurchase, Securities Loaned, Gross Gross Amounts Offset in Consolidated Balance Sheet Derivative Liability, Securities Sold under Agreements to Repurchase, Securities Loaned, Asset Net Amounts of Assets (Liabilities) Presented in Consolidated Balance Sheet Derivative Liability, Securities Sold under Agreements to Repurchase, Securities Loaned Gross Amounts Not Offset in Consolidated Balance Sheet, Financial Instruments Derivative Liability, Securities Sold under Agreements to Repurchase, Securities Loaned, Collateral, Right to Reclaim Securities Gross Amounts Not Offset in Consolidated Balance Sheet, Cash Collateral (Received) Pledged Derivative Liability, Securities Sold under Agreements to Repurchase, Securities Loaned, Collateral, Right to Reclaim Cash Net Amount Derivative Liability, Securities Sold under Agreements to Repurchase, Securities Loaned, Amount Offset Against Collateral Multifamily Loans Residential Loans Residential Mortgage [Member] At fair value At lower of cost or fair value Residential Loans at Lower of Cost or Fair Value [Member] Residential Loans at Lower of Cost or Fair Value [Member] Total held-for-sale SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Loan Type [Axis] SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Loan Type [Axis] SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Loan Type [Domain] SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Loan Type [Domain] Jumbo Loans Jumbo Loan [Member] Jumbo Loan [Member] Residential loans Available-for-sale New Accounting Pronouncements or Change in Accounting Principle [Table] New Accounting Pronouncements or Change in Accounting Principle [Table] Adjustments for New Accounting Pronouncements [Axis] Adjustments for New Accounting Pronouncements [Axis] Type of Adoption [Domain] Type of Adoption [Domain] ASU 2016-02 Accounting Standards Update 2016-02 [Member] New Accounting Pronouncements or Change in Accounting Principle [Line Items] New Accounting Pronouncements or Change in Accounting Principle [Line Items] Right-of-use asset Operating Lease, Right-of-Use Asset Investments, All Other Investments [Abstract] Investment [Table] Investment [Table] Mortgage servicing rights Investment in multifamily loan fund Other Other Notes Receivable [Member] Other Notes Receivable [Member] Investment [Line Items] Investment [Line Items] Servicing asset, fair value Loan Held-for-investment, Amount Loan Held-For-Investment, Amount Loan Held-for-investment, Amount Investment in 5 Arches Equity Method Investments Including Purchase Option Equity Method Investments Including Purchase Option Other Investments Cover page. Document Type Document Type Document Quarterly Report Document Quarterly Report Document Period End Date Document Period End Date Document Transition Report Document Transition Report Entity File Number Entity File Number Entity Registrant Name Entity Registrant Name Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Entity Tax Identification Number Entity Tax Identification Number Entity Address Address Line Entity Address, Address Line One Entity Address City Or Town Entity Address, City or Town Entity Address, State or Province Entity Address, State or Province Entity Address Postal Zip Code Entity Address, Postal Zip Code City Area Code City Area Code Local Phone Number Local Phone Number Entity Current Reporting Status Entity Current Reporting Status Entity Interactive Data Current Entity Interactive Data Current Entity Filer Category Entity Filer Category Entity small business Entity Small Business Emerging growth company Entity Emerging Growth Company Entity Shell Company Entity Shell Company Title of 12(b) Security Title of 12(b) Security Trading Symbol Trading Symbol Security Exchange Name Security Exchange Name Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Entity Central Index Key Entity Central Index Key Current Fiscal Year End Date Current Fiscal Year End Date Amendment Flag Amendment Flag Collateral [Axis] Collateral [Axis] Collateral [Domain] Collateral [Domain] Residential Real Estate Residential Real Estate [Member] Fixed rate residential mortgage Fixed Rate Residential Mortgage [Member] Hybrid or ARM Loans Hybrid Or ARM Loans [Member] Hybrid Or ARM Loans [Member] Held-for-sale residential loans Federal Home Loan Bank Branch [Axis] Federal Home Loan Bank Branch [Axis] Federal Home Loan Bank Branch [Domain] Federal Home Loan Bank Branch [Domain] FHLB Chicago Federal Home Loan Bank of Chicago [Member] SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Loan Category [Axis] SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Loan Category [Axis] SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Loan Category [Domain] SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Loan Category [Domain] Originated Between 2013 and 2019 Originated Between 2013 And 2019 [Member] Originated Between 2013 And 2019 [Member] Originated 2012 and prior years Originated During Twenty Twelve And Prior Years [Member] Originated During Twenty Twelve And Prior Years [Member] Mortgage servicing rights, at amortized cost Servicing Asset at Amortized Cost Loans held-for-investment, delinquent greater than 90 days Fair Value, Option, Loans Held as Assets, 90 Days or More Past Due Principal value of loans purchased Principal Balance of Loans Acquired During Period Principal Balance of Loans Acquired During Period Principal balance of loans sold during period Principal Balance of Loans Sold During Period Principal Balance of Loans Sold During Period Gain (loss) on assets measured at fair value on a non-recurring basis Fair Value, Option, Changes in Fair Value, Gain (Loss) Loan pledged as collateral Loans Pledged as Collateral Transfers from loans held-for-sale to loans held-for-investment Transfer of Loans Held-for-sale to Portfolio Loans Transfers from loans held-for-investment to loans held-for-sale Transfer of Portfolio Loans and Leases to Held-for-sale Loans pledged as collateral under borrowing agreement with FHLBC Federal Home Loan Bank, Advances, General Debt Obligations, Disclosures, Collateral Pledged Percentage of loan portfolio originated in year Percentage Of Loan Portfolio Percentage Of Loan Portfolio Percentage of fixed-rate loans Loans Receivable, Percentage Bearing Fixed Interest, Percentage Rate Loans Receivable, Percentage Bearing Fixed Interest, Percentage Rate Loans held-for-investment, in foreclosure Fair Value, Option, Loans Held As Assets, Aggregate Amount In Foreclosure Fair Value, Option, Loans Held As Assets, Aggregate Amount In Foreclosure Asset-Backed Securities Issued Schedule of Asset Backed Securities [Table Text Block] Tabular disclosure of information pertaining to asset backed securities, including but not limited to identification of components, terms, features, and other information necessary to a fair presentation. Accrued Interest Payable on Asset-Backed Securities Issued Schedule Of Interest Payable On Asset-Backed Securities Issued [Table Text Block] Schedule Of Interest Payable On Asset-Backed Securities Issued [Table Text Block] Collateral for ABS Issued Schedule Of Collateral For Asset Backed Securities [Table Text Block] Tabular disclosure of the collateral for asset backed securities. Activity of the Credit Component of Other-than-Temporary Impairments Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward] Balance at beginning of period Other than Temporary Impairment, Credit Losses Recognized in Earnings, Credit Losses on Debt Securities Held Additions Additions [Abstract] Additions [Abstract] Initial credit impairments Other than Temporary Impairment, Credit Losses Recognized in Earnings, Additions, No Previous Impairment Reductions Other than Temporary Impairment, Credit Losses Recognized in Earnings, Reductions [Abstract] Other than Temporary Impairment, Credit Losses Recognized in Earnings, Reductions [Abstract] Securities sold, or expected to sell Other than Temporary Impairment, Credit Losses Recognized in Earnings, Reductions, Securities Sold Securities with no outstanding principal at period end Other Than Temporary Impairment Credit Losses Recognized In Earnings Matured Called Written Down This item represents reductions in the amount of cumulative losses recognized in earnings for other than temporary impairments (OTTI) for which a portion of the impairment had been recognized in other comprehensive income (a component of shareholders' equity) due to securities maturing, being called or fully written down. Balance at End of Period Other Income and Expenses [Abstract] Fixed compensation expense Fixed Compensation Expense Fixed Compensation Expense Variable compensation expense Variable Compensation Expense Variable Compensation Expense Equity compensation expense Share-based Payment Arrangement, Expense Total compensation expense Labor and Related Expense Systems and consulting Communications and Information Technology Loan acquisition costs Loan Acquisition Costs Loan Acquisition Costs Office costs General and Administrative Expense Accounting and legal Professional Fees Corporate costs Other General Expense Other operating expenses Other Cost and Expense, Operating Total Operating Expenses Federal statutory rate Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent State statutory rate, net of Federal tax effect Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Percent Differences in taxable (loss) income from GAAP income Effective Income Tax Rate Reconciliation, Deduction, Percent Change in valuation allowance Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Percent Dividends paid deduction Effective Income Tax Rate Reconciliation, Deduction, Dividend, Percent Effective Tax Rate Effective Income Tax Rate Reconciliation, Percent Accrued compensation Employee-related Liabilities Guarantee obligations Guaranty Liabilities Deferred tax liabilities Deferred Income Tax Liabilities, Net Margin payable Margin Payable Margin Payable Accrued operating expenses Accrued Expenses Accrued Expenses Residential bridge loan holdbacks Bridge Loan Holdback Bridge Loan Holdback Residential loan and MSR repurchase reserve Mortgage Loan On Real Estate, Repurchase Reserve Mortgage Loan On Real Estate, Repurchase Reserve Legal reserve Estimated Litigation Liability Other Other Liabilities, Miscellaneous Other Liabilities, Miscellaneous Total Accrued Expenses and Other Liabilities Fair Values of Real Estate Securities by Type Fair Value And Investments In Debt And Marketable Equity Securities And Certain Trading Assets Disclosures [Table Text Block] Tabular disclosure of fair value and investments in debt and marketable equity securities. Trading Securities by Collateral Type Debt Securities, Trading, and Equity Securities, FV-NI [Table Text Block] Available-for-Sale Securities by Collateral Type Debt Securities, Available-for-sale [Table Text Block] Carrying Value of Residential Available for Sale Securities Schedule of Available-for-sale Securities Reconciliation [Table Text Block] Changes of Unamortized Discount and Designated Credit Reserves on Residential Available for Sale Securities Unamortized Discount and Designated Credit Reserves on Available for Sale Securities [Table Text Block] Tabular disclosure of the changes in the unamortized discount and designated credit reserves on Available for Sale securities for the period. Components of Fair Value of Available for Sale Securities by Holding Periods Debt Securities, Available-for-sale, Unrealized Loss Position, Fair Value [Table Text Block] Summary of Significant Valuation Assumptions for Available for Sale Securities Schedule Of Significant Valuation Assumptions For Available For Sale Securities [Table Text Block] Tabular disclosure of the significant valuation assumptions used by management for available for sale securities. Activity of Credit Component of Other-than-Temporary Impairments Other than Temporary Impairment, Credit Losses Recognized in Earnings [Table Text Block] Gross Realized Gains and Losses on Available for Sale Securities Realized Gain (Loss) on Investments [Table Text Block] Investment Fair Value Changes, Net Investment Activities [Member] Investment Activities [Member] Residential loans held-for-investment, at Redwood Residential Loans Held for Investment [Member] Residential Loans Held for Investment [Member] Single-family rental loans held-for-investment Residential bridge loans Trading securities Net investments in Legacy Sequoia entities Net investments in Sequoia Choice entities Net investments in Freddie Mac SLST entities Net investments in Freddie Mac K-Series entities Risk-sharing investments Risk Sharing Investments [Member] Risk Sharing Investments [Member] Risk management derivatives, net Impairments on AFS securities Impaired Securities [Member] Impaired Securities [Member] Carrying Values and Fair Values of Assets and Liabilities Fair Value, by Balance Sheet Grouping [Table Text Block] Assets and Liabilities Measured at Fair Value on Recurring Basis Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Changes in Level 3 Assets and Liabilities Measured at Fair Value on Recurring Basis Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block] Portion of Net Gains (Losses) Attributable to Level 3 Assets and Liabilities Still Held and Included in Net Income Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings [Table Text Block] Assets and Liabilities Measured at Fair Value on Non-Recurring Basis Fair Value Measurements, Nonrecurring [Table Text Block] Market Valuation Gains and Losses, Net Schedule Of Market Valuation Adjustments Included In Earnings [Table Text Block] Tabular disclosure for the total amount of market valuation adjustments for the period which are included in earnings. Quantitative Information about Significant Unobservable Inputs Used in Valuation of Level 3 Assets and Liabilities Measured at Fair Value Fair Value Measurement Inputs and Valuation Techniques [Table Text Block] Residential Loans Principal and interest advances Servicing Assets At Fair Value, Principal And Interest Advances Servicing Assets At Fair Value, Principal And Interest Advances Escrow advances (taxes and insurance advances) Servicing Assets At Fair Value, Escrow Advances Servicing Assets At Fair Value, Escrow Advances Corporate advances Servicing Assets At Fair Value, Corporate Advances Servicing Assets At Fair Value, Corporate Advances Total Servicer Advance Receivables Derivative [Table] Derivative [Table] Derivative Assets Derivative Financial Instruments, Assets [Member] Derivative Liabilities Derivative Financial Instruments, Liabilities [Member] Derivative Instrument [Axis] Derivative Instrument [Axis] Derivative Contract [Domain] Derivative Contract [Domain] Interest rate swaps Swaptions Interest Rate Swaption [Member] Hedging Relationship [Axis] Hedging Relationship [Axis] Hedging Relationship [Domain] Hedging Relationship [Domain] Cash Flow Hedging Cash Flow Hedging [Member] Derivative [Line Items] Derivative [Line Items] Fair Value Derivative, Fair Value, Net Notional Amount Derivative, Notional Amount Mortgage Banking Activities, Net Mortgage Banking Activities [Member] Mortgage Banking Activities [Member] Other Income (Expense), Net Mortgage Servicing Rights Income (Loss), Including Risk Management Derivatives [Member] Mortgage Servicing Rights Income (Loss), Including Risk Management Derivatives [Member] Residential loan purchase and forward sale commitments Loan Purchase and Forward Sales Commitments [Member] Loan Purchase and Forward Sales Commitments [Member] Single-family rental loans held-for-sale, at fair value Single-Family Residential Loans Held-for-sale at Fair Value [Member] Single-Family Residential Loans Held-for-sale at Fair Value [Member] Single-family rental loan purchase commitments Residential bridge loans Commercial Loans at Fair Value [Member] Commercial Loans at Fair Value [Member] Residential bridge loans held-for-investment Shared home appreciation options Other Income (Expense), Net Mortgage Servicing Rights Income (Loss), Net Includes income (loss) from mortgage banking servicing real estate mortgages, net of subservicing costs, and market valuation changes of MSRs held at fair value. Gain on re-measurement of 5 Arches investment Business Combination, Step Acquisition, Equity Interest in Acquiree, Remeasurement Gain Total Market Valuation Gains, Net Market Valuation Adjustments, Net The aggregate net change in market value for certain assets and liabilities that was included in earnings for the period. This includes changes in market values for assets and liabilities accounted for at fair value, as well as the credit portion of other-than-temporary impairments on securities available for sale, impairments on loans held-for-sale and real estate owned. Assets and Liabilities of Consolidated VIEs Schedule of Variable Interest Entities [Table Text Block] Securitization Activity Related to Unconsolidated Variable Interest Entity's Sponsored by Redwood Schedule of Gain (Loss) on Securitizations or Asset-backed Financing Arrangements of Financial Assets Accounted for as Sale [Table Text Block] Cash Flows Related to Unconsolidated Variable Interest Entity's Sponsored by Redwood Cash Flows between Transferee and Transferor Current Period [Table Text Block] Cash Flows between a transferor and a transferee attributable to transferred assets related to either a securitization 0r asset-backed financing arrangement in which the transferor has continuing involvement with the transferred financial assets underlying the transaction (including, but not limited to, servicing, recourse, and restrictions on transferor's interests in the transferred financial assets). Assumptions Related to Assets Retained from Unconsolidated Variable Interest Entity's Sponsored by Redwood Schedule of Fair Value Assumption, Date of Securitization or Asset-backed Financing Arrangement, Transferor's Continuing Involvement, Servicing Assets or Liabilities [Table Text Block] Unconsolidated Variable Interest Entity's Sponsored by Redwood Qualitative and Quantitative Information, Transferor's Continuing Involvement [Table Text Block] Key Assumptions and Sensitivity Analysis for Assets Retained from Unconsolidated Variable Interest Entity's Sponsored by Redwood Schedule of Sensitivity Analysis of Fair Value, Transferor's Interests in Transferred Financial Assets [Table Text Block] Schedule of Third-Party Sponsored VIE Summary Schedule of Third-Party Sponsored VIE Summary [Table Text Block] Schedule of Third-Party Sponsored VIE Summary [Table Text Block] MSR income, net Risk share income Fee Income, Risk Sharing Agreement Fee Income, Risk Sharing Agreement FHLBC capital stock dividend FHLBC Capital Stock Dividend FHLBC Capital Stock Dividend Equity investment income Income (Loss) from Equity Method Investments 5 Arches loan administration fee income Property Management Fee Revenue Amortization of intangible assets Gain on re-measurement of investment in 5 Arches Other Other Nonoperating Expense Other Income, Net Short-Term Debt Short-term Debt [Text Block] Asset-Backed Securities Issued Secured Borrowings Disclosure [Text Block] This item represents the disclosure related to the asset-backed securities issued under the Sequoia and Acacia securitization entities, and the Residential Resecuritization and Commercial Securitization entities, including their respective components, collateral, and accrued interest payable. Margin receivable Margin Deposit Assets FHLBC stock Federal Home Loan Bank Stock Investment receivable Accrued Investment Income Receivable REO Fixed assets and leasehold improvements Property, Plant and Equipment, Net Other Other Assets, Miscellaneous Total Other Assets Fixed assets Property, Plant and Equipment, Gross Accumulated depreciation Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Loss Contingencies [Table] Loss Contingencies [Table] Commitment To Fund Temporary Advances On Residential Bridge Loans Commitment To Fund Temporary Advances On Residential Bridge Loans [Member] Commitment To Fund Temporary Advances On Residential Bridge Loans [Member] Commitment To Fund Investment Commitment To Fund Investment [Member] Commitment To Fund Investment [Member] Guarantor Obligations, Nature [Axis] Guarantor Obligations, Nature [Axis] Guarantor Obligations, Nature [Domain] Guarantor Obligations, Nature [Domain] Financial Guarantee Financial Guarantee [Member] Loss Contingency Nature [Axis] Loss Contingency Nature [Axis] Loss Contingency, Nature [Domain] Loss Contingency, Nature [Domain] Guarantee Obligations Guarantee Obligations [Member] Residential Residential Mortgage Backed Securities [Member] Income Statement Location [Axis] Income Statement Location [Axis] Income Statement Location [Domain] Income Statement Location [Domain] Other income Other Income [Member] Mortgage banking and investment activities Mortgage Banking And Investment Activities [Member] Mortgage Banking And Investment Activities [Member] Sequoia Sequoia Securitization Entities [Member] Sequoia Securitization Entities [Member] Loss Contingencies by Name of Plaintiff [Axis] Loss Contingencies by Name of Plaintiff [Axis] Loss Contingencies by Name of Plaintiff [Axis] Loss Contingencies by Name of Plaintiff [Domain] Loss Contingencies by Name of Plaintiff [Domain] Loss Contingencies by Name of Plaintiff [Domain] FHLB Seattle Federal Home Loan Bank of Seattle [Member] Schwab Charles Schwab Corporation [Member] Charles Schwab Corporation [Member] Morgan Stanley And Company Morgan Stanley And Company [Member] Morgan Stanley And Company [Member] Sequoia Residential Funding Sequoia Residential Funding [Member] Sequoia Residential Funding [Member] Loss Contingencies [Line Items] Loss Contingencies [Line Items] Lessee, number of leases Lessee, Number Of Leases Lessee, Number Of Leases Present value of remaining lease payments Operating lease expense Operating Lease, Cost Number of noncancelable leases Operating Leases, Number Of Leases, Noncancelable Operating Leases, Number Of Leases, Noncancelable Number of leases qualified as short-term lease Lessee, Operating Lease, Number Of Leases Qualified As Short-Term Lease Lessee, Operating Lease, Number Of Leases Qualified As Short-Term Lease Number of leases without implicit interest rate Lessee, Operating Lease, Number Of Leases Without Implicit Interest Rate Lessee, Operating Lease, Number Of Leases Without Implicit Interest Rate Weighted average remaining lease term Operating Lease, Weighted Average Remaining Lease Term Discount rate Operating Lease, Weighted Average Discount Rate, Percent Commitments to fund temporary advances Number of partnerships, committed to fund Commitment To Fund Partnership, Number Of Partnerships Commitment To Fund Partnership, Number Of Partnerships Commitment to fund partnership Commitment To Fund Partnership Commitment To Fund Partnership Guarantor obligations, current carrying value Guarantor Obligations, Current Carrying Value Guarantor obligations, maximum exposure, undiscounted Guarantor Obligations, Maximum Exposure, Undiscounted Contingent consideration maximum amount Business Combination, Contingent Consideration, Liability, Maximum Exposure Business Combination, Contingent Consideration, Liability, Maximum Exposure Contingent consideration expense Business Combination, Contingent Consideration Expense Business Combination, Contingent Consideration Expense Payments to acquire investments Payments to Acquire Investments Original unpaid balance of loans subject to risk sharing agreements Principal Amount Outstanding on Loans Securitized or Asset-backed Financing Arrangement, Original Principal Balance Principal Amount Outstanding on Loans Securitized or Asset-backed Financing Arrangement, Original Principal Balance Potential future payments on loans Potential Future Payments Potential Future Payments Other income related to risk sharing agreement Market valuation losses related to these investments Market Valuation Changes In Fair Value Of Guarantee Asset Market Valuation Changes In Fair Value Of Guarantee Asset Balance of loans 90 days or more delinquent Financing Receivable, Past Due Guarantee obligations, credit reserve Guarantee Obligation, Credit Reserve Guarantee Obligation, Credit Reserve Special Purpose Entities (SPEs) assets Special Purpose Entities, Assets Special Purpose Entities, Assets Special Purpose Entities (SPEs) liabilities Special Purpose Entities, Liabilities Special Purpose Entities, Liabilities Residential repurchase reserve Number of residential repurchase requests (in repurchase requests) Mortgage Loans On Real Estate, Repurchase Requests Mortgage Loans On Real Estate, Repurchase Requests Number of loans repurchased Mortgage Loans On Real Estate, Number Of Loans Repurchased Mortgage Loans On Real Estate, Number Of Loans Repurchased Residential repurchase provisions recorded Mortgage Loans On Real Estate, Repurchase Provision Mortgage Loans On Real Estate, Repurchase Provision Principal value Debt Instrument, Face Amount Debt instrument principal payment amount Repayments of Bank Debt Debt instrument interest payment amount Debt Instrument Unpaid Interest Paid By Cash Debt Instrument Unpaid Interest Paid By Cash Number of other named defendants along with SRF (in plaintiffs) Loss Contingency, Number of Defendants Principal balance of securities Debt Instrument Aggregate Principal Amount Debt Instrument Aggregate Principal Amount Debt instrument interest amount Debt Instrument Accrued Interest Debt Instrument Accrued Interest Number of mortgage pass-through certificates issued (in certificates) Number Of Mortgage Pass Through Certificates Issued Number Of Mortgage Pass Through Certificates Issued Number of certificated withdrawn Number Of Mortgage Pass Through Certificates Issued, Subsequently Withdrawn From Litigation Number Of Mortgage Pass Through Certificates Issued, Subsequently Withdrawn From Litigation Aggregate amount of loss contingency reserves Schedule of Fair Value Assumption, Date of Securitization or Asset-backed Financing Arrangement, Transferor's Continuing Involvement, Servicing Assets or Liabilities [Table] Schedule of Fair Value Assumption, Date of Securitization or Asset-backed Financing Arrangement, Transferor's Continuing Involvement, Servicing Assets or Liabilities [Table] Fair Value Assumption, Date of Securitization or Asset-backed Financing Arrangement, Transferor's Continuing Involvement, Servicing Assets or Liabilities [Line Items] Fair Value Assumption, Date of Securitization or Asset-backed Financing Arrangement, Transferor's Continuing Involvement, Servicing Assets or Liabilities [Line Items] Prepayment rates Fair Value Assumption, Date of Securitization or Asset-backed Financing Arrangement, Transferor's Continuing Involvement, Servicing Assets or Liabilities, Prepayment Speed Discount rates Fair Value Assumption, Date of Securitization or Asset-backed Financing Arrangement, Transferor's Continuing Involvement, Servicing Assets or Liabilities, Discount Rate Credit loss assumptions Fair Value Assumption, Date of Securitization or Asset-backed Financing Arrangement, Transferor's Continuing Involvement, Servicing Assets or Liabilities, Expected Credit Losses Mortgage Banking Activities Income and Expense Attributable To Mortgage Banking Activities [Table Text Block] Tabular disclosure of the components of mortgage banking activities, net. This includes market valuations related to residential and commercial loans, retained Sequoia IOs, and mortgage banking derivatives, as well as realized gains or losses associated with residential and commercial loan sales and securitizations. Interest rate contract Interest Rate Contract [Member] Unsecuritized Residential and Commercial Loans Residential and Commercial Loans [Member] Residential and Commercial Loans [Member] Loan purchase commitments and forward sales commitments Loan Purchase Commitments And Forward Sales Commitments [Member] Loan Purchase Commitments And Forward Sales Commitments [Member] Net Unrealized Losses on Interest Rate Agreements Accounted for as Cash Flow Hedges Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent [Member] Net Unrealized Losses on Interest Rate Agreements Accounted for as Cash Flow Hedges Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member] Notional amount Derivative gain (loss) Derivative, Gain (Loss) on Derivative, Net Market valuations gains (losses), net Accumulated other comprehensive income (loss) Stockholders' Equity Attributable to Parent Number of counterparties Derivative, Number Of Counterparties Derivative, Number Of Counterparties Option Indexed to Issuer's Equity [Axis] Option Indexed to Issuer's Equity [Axis] Option Indexed to Issuer's Equity, Type [Domain] Option Indexed to Issuer's Equity, Type [Domain] Sales Put Option [Member] Calls Call Option [Member] Gross realized gains Debt Securities, Available-for-sale, Realized Gain Gross realized losses - sales Debt Securities, Available-for-sale, Realized Loss Total Realized Gains on Sales and Calls of AFS Securities, net Available-for-sale Securities, Gross Realized Gain (Loss) On Sales And Calls Available-for-sale Securities, Gross Realized Gain (Loss) On Sales And Calls Fair Value Measurement Inputs and Valuation Techniques [Table] Fair Value Measurement Inputs and Valuation Techniques [Table] Jumbo fixed-rate loans Residential Loans Priced To Securitization and Whole Loan Market, Uncommitted to Sell [Member] Residential Loans Priced To Securitization and Whole Loan Market, Uncommitted to Sell [Member] Jumbo hybrid loans Residential Jumbo Hybrid Loans Priced To Whole Loan Market Uncommitted To Sell [Member] Residential Jumbo Hybrid Loans Priced To Whole Loan Market Uncommitted To Sell [Member] Jumbo loans committed to sell Residential Loans Priced To Whole Loan Market and Committed to Sell [Member] Residential Loans Priced To Whole Loan Market and Committed to Sell [Member] Trading and AFS securities Investment Securities [Member] Investment Securities [Member] Guarantee asset Guarantee Asset [Member] Guarantee Asset [Member] ABS Issued ABS Issued Securities [Member] ABS Issued Securities [Member] Contingent consideration Measurement Input Type [Axis] Measurement Input Type [Axis] Measurement Input Type [Domain] Measurement Input Type [Domain] Prepayment rate (annual CPR) Measurement Input, Prepayment Rate [Member] Whole loan spread to TBA price Measurement Input, Whole Loan Spread To TBA Price [Member] Measurement Input, Whole Loan Spread To TBA Price [Member] Whole loan spread to swap rate Measurement Input, Whole Loan Spread To Swap Price [Member] Measurement Input, Whole Loan Spread To Swap Price [Member] Whole loan committed sales price Measurement Input, Whole Loan Committed Sales Price [Member] Measurement Input, Whole Loan Committed Sales Price [Member] Discount rate Measurement Input, Discount Rate [Member] Senior credit spread Senior Credit Spread [Member] Senior Credit Spread [Member] Subordinate credit spread Measurement Input, Subordinate Credit Spread [Member] Measurement Input, Subordinate Credit Spread [Member] Senior credit support Senior Credit Support [Member] Senior Credit Support [Member] Default rate Measurement Input, Default Rate [Member] Loss severity Measurement Input, Loss Severity [Member] Mortgage servicing income Measurement Input Mortgage Servicing Income [Member] Measurement Input Mortgage Servicing Income [Member] Per loan annual cost to service Measurement Input, Per Loan Annual Cost To Service [Member] Measurement Input, Per Loan Annual Cost To Service [Member] Excess mortgage servicing income Measurement Input, Mortgage Servicing Amount [Member] Measurement Input, Mortgage Servicing Amount [Member] Home price appreciation Measurement Input, Home Price Appreciation [Member] Measurement Input, Home Price Appreciation [Member] MSR multiple Measurement Input, Mortgage Servicing Rights Multiple [Member] Measurement Input, Mortgage Servicing Rights Multiple [Member] Pull-through rate Measurement Input, Pull-through Rate [Member] Measurement