XML 74 R62.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Fair Value of Financial Instruments - Additional Information (Details) $ in Millions | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2018 USD ($) | Sep. 30, 2018 USD ($)
Residential loans |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |
Fair value option elected aggregate carrying amount, asset | $ 1,790 | $ 5,520
Business purpose loans, at fair value |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |
Fair value option elected aggregate carrying amount, asset | 126 |
Multifamily loans, held-for-investment, at fair value |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |
Fair value option elected aggregate carrying amount, asset | $ 963 |
Real estate securities | Maximum |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |
Dealer marks of securities (as a percent) | 79.00% | 79.00%
Carrying value for which dealer quotes have been received (as a percent) | 86.00% | 86.00%
Difference of internal valuation than dealer marks (as a percent) | 1.00% | 1.00%
Residential Senior Securities |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |
Fair value option elected aggregate carrying amount, asset | $ 32 | $ 105
Residential Subordinate Securities | Subordinate Securities |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |
Fair value option elected aggregate carrying amount, asset | $ 128 | $ 417
Mortgage servicing rights | Maximum |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |
Difference of internal valuation than dealer marks (as a percent) | 2.00% | 2.00%

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 Percentage Difference Of Internal Valuation Than Dealer Marks + References No definition available. + Details
Name: | rwt_PercentageDifferenceOfInternalValuationThanDealerMarks
Namespace Prefix: | rwt_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Percentage of Carrying Value for Which Dealer Quotes Were Received on Securities + References No definition available. + Details
Name: | rwt_PercentageOfCarryingValueForWhichDealerQuotesWereReceivedOnSecurities
Namespace Prefix: | rwt_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Percentage of Third-party Dealer Quotes Received on Securities. + References No definition available. + Details
Name: | rwt_PercentageOfDealerQuotesReceivedOnSecurities
Namespace Prefix: | rwt_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

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_ResidentialLoansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

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

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

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | invest_InvestmentSecuritiesClassAxis=rwt_ResidentialSeniorSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | invest_InvestmentSecuritiesClassAxis=rwt_ResidentialSubordinateSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

X
- Details
Name: | invest_InvestmentSecuritiesClassAxis=rwt_MortgageServicingRightsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |