XML 85 R71.htm IDEA: XBRL DOCUMENT
v3.20.2

Fair Value of Financial Instruments - Additional Information (Details) - USD ($) | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2020 | Sep. 30, 2020
Securities |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |
Fair value option elected aggregate carrying amount, asset | $ 18,000,000 | $ 96,000,000
Residential loans |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |
Fair value option elected aggregate carrying amount, asset | 172,000,000 | 2,860,000,000
Business purpose residential loans |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |
Fair value option elected aggregate carrying amount, asset | 260,000,000 | 956,000,000
Servicer advance investments |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |
Fair value option elected aggregate carrying amount, asset | 0 | 179,000,000
Excess MSR |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |
Fair value option elected aggregate carrying amount, asset | 0 | 11,000,000
Shared home appreciation options |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |
Fair value option elected aggregate carrying amount, asset | $ 0 | $ 4,000,000

X
- Definition Fair Value, Option, Assets, Aggregate Carrying Amount During Period + References No definition available. + Details
Name: | rwt_FairValueOptionAssetsAggregateCarryingAmountDuringPeriod
Namespace Prefix: | rwt_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_FairValueByAssetClassAxis=rwt_SecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByAssetClassAxis=rwt_ResidentialLoansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByAssetClassAxis=rwt_BusinessPurposeResidentialLoansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=rwt_ServicerAdvanceInvestmentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=rwt_ExcessMortgageServicingRightsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=rwt_HomeAppreciationOptionMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |