XML 25 R70.htm IDEA: XBRL DOCUMENT v2.4.1.9
Quantitative Information about Significant Unobservable Inputs Used in Valuation of Level 3 Assets and Liabilities Measured at Fair Value (Detail) (USD $)
12 Months Ended
Dec. 31, 2014
Minimum  
Fair Value Inputs, Assets, Quantitative Information [Line Items]  
Discount rate 11.00%us-gaap_FairValueInputsDiscountRate
/ us-gaap_RangeAxis
= us-gaap_MinimumMember
Prepayment rate 5.00%us-gaap_FairValueInputsPrepaymentRate
/ us-gaap_RangeAxis
= us-gaap_MinimumMember
Maximum  
Fair Value Inputs, Assets, Quantitative Information [Line Items]  
Discount rate 11.00%us-gaap_FairValueInputsDiscountRate
/ us-gaap_RangeAxis
= us-gaap_MaximumMember
Prepayment rate 27.00%us-gaap_FairValueInputsPrepaymentRate
/ us-gaap_RangeAxis
= us-gaap_MaximumMember
Weighted Average  
Fair Value Inputs, Assets, Quantitative Information [Line Items]  
Discount rate 11.00%us-gaap_FairValueInputsDiscountRate
/ us-gaap_RangeAxis
= us-gaap_WeightedAverageMember
Prepayment rate 11.00%us-gaap_FairValueInputsPrepaymentRate
/ us-gaap_RangeAxis
= us-gaap_WeightedAverageMember
Residential Jumbo Hybrid Loans Priced To Whole Loan Market Uncommitted To Sell  
Fair Value Inputs, Assets, Quantitative Information [Line Items]  
Fair Value 150,065,000us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisWithUnobservableInputs
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_ResidentialJumboHybridLoansPricedToWholeLoanMarketUncommittedToSellMember
Residential Jumbo Hybrid Loans Priced To Whole Loan Market Uncommitted To Sell | Minimum  
Fair Value Inputs, Assets, Quantitative Information [Line Items]  
Discount rate 5.00%us-gaap_FairValueInputsDiscountRate
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_ResidentialJumboHybridLoansPricedToWholeLoanMarketUncommittedToSellMember
/ us-gaap_RangeAxis
= us-gaap_MinimumMember
Prepayment rate 10.00%us-gaap_FairValueInputsPrepaymentRate
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_ResidentialJumboHybridLoansPricedToWholeLoanMarketUncommittedToSellMember
/ us-gaap_RangeAxis
= us-gaap_MinimumMember
Senior credit spread 3.00%rwt_FairValueInputsSeniorCreditSpreads
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_ResidentialJumboHybridLoansPricedToWholeLoanMarketUncommittedToSellMember
/ us-gaap_RangeAxis
= us-gaap_MinimumMember
Subordinate credit spread 3.26%rwt_FairValueInputsSubordinateCreditSpreads
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_ResidentialJumboHybridLoansPricedToWholeLoanMarketUncommittedToSellMember
/ us-gaap_RangeAxis
= us-gaap_MinimumMember
Credit support 8.00%rwt_FairValueInputsCreditSupport
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_ResidentialJumboHybridLoansPricedToWholeLoanMarketUncommittedToSellMember
/ us-gaap_RangeAxis
= us-gaap_MinimumMember
Whole loan credit spread 2.90%rwt_FairValueInputsWholeLoanCreditSpreads
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_ResidentialJumboHybridLoansPricedToWholeLoanMarketUncommittedToSellMember
/ us-gaap_RangeAxis
= us-gaap_MinimumMember
Residential Jumbo Hybrid Loans Priced To Whole Loan Market Uncommitted To Sell | Maximum  
Fair Value Inputs, Assets, Quantitative Information [Line Items]  
Discount rate 8.00%us-gaap_FairValueInputsDiscountRate
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_ResidentialJumboHybridLoansPricedToWholeLoanMarketUncommittedToSellMember
/ us-gaap_RangeAxis
= us-gaap_MaximumMember
Prepayment rate 12.00%us-gaap_FairValueInputsPrepaymentRate
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_ResidentialJumboHybridLoansPricedToWholeLoanMarketUncommittedToSellMember
/ us-gaap_RangeAxis
= us-gaap_MaximumMember
Senior credit spread 3.00%rwt_FairValueInputsSeniorCreditSpreads
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_ResidentialJumboHybridLoansPricedToWholeLoanMarketUncommittedToSellMember
/ us-gaap_RangeAxis
= us-gaap_MaximumMember
Subordinate credit spread 3.26%rwt_FairValueInputsSubordinateCreditSpreads
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_ResidentialJumboHybridLoansPricedToWholeLoanMarketUncommittedToSellMember
/ us-gaap_RangeAxis
= us-gaap_MaximumMember
Credit support 8.00%rwt_FairValueInputsCreditSupport
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_ResidentialJumboHybridLoansPricedToWholeLoanMarketUncommittedToSellMember
/ us-gaap_RangeAxis
= us-gaap_MaximumMember
Whole loan credit spread 4.25%rwt_FairValueInputsWholeLoanCreditSpreads
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_ResidentialJumboHybridLoansPricedToWholeLoanMarketUncommittedToSellMember
/ us-gaap_RangeAxis
= us-gaap_MaximumMember
Residential Jumbo Hybrid Loans Priced To Whole Loan Market Uncommitted To Sell | Weighted Average  
Fair Value Inputs, Assets, Quantitative Information [Line Items]  
Discount rate 7.00%us-gaap_FairValueInputsDiscountRate
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_ResidentialJumboHybridLoansPricedToWholeLoanMarketUncommittedToSellMember
/ us-gaap_RangeAxis
= us-gaap_WeightedAverageMember
Prepayment rate 11.00%us-gaap_FairValueInputsPrepaymentRate
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_ResidentialJumboHybridLoansPricedToWholeLoanMarketUncommittedToSellMember
/ us-gaap_RangeAxis
= us-gaap_WeightedAverageMember
Senior credit spread 3.00%rwt_FairValueInputsSeniorCreditSpreads
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_ResidentialJumboHybridLoansPricedToWholeLoanMarketUncommittedToSellMember
/ us-gaap_RangeAxis
= us-gaap_WeightedAverageMember
Subordinate credit spread 3.26%rwt_FairValueInputsSubordinateCreditSpreads
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_ResidentialJumboHybridLoansPricedToWholeLoanMarketUncommittedToSellMember
/ us-gaap_RangeAxis
= us-gaap_WeightedAverageMember
Credit support 8.00%rwt_FairValueInputsCreditSupport
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_ResidentialJumboHybridLoansPricedToWholeLoanMarketUncommittedToSellMember
/ us-gaap_RangeAxis
= us-gaap_WeightedAverageMember
Whole loan credit spread 4.11%rwt_FairValueInputsWholeLoanCreditSpreads
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_ResidentialJumboHybridLoansPricedToWholeLoanMarketUncommittedToSellMember
/ us-gaap_RangeAxis
= us-gaap_WeightedAverageMember
Residential Jumbo Loans Priced To Whole Loan Market Uncommitted To Selll [Member] | Minimum  
Fair Value Inputs, Assets, Quantitative Information [Line Items]  
Prepayment rate 15.00%us-gaap_FairValueInputsPrepaymentRate
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_ResidentialJumboLoansPricedToWholeLoanMarketUncommittedToSelllMember
/ us-gaap_RangeAxis
= us-gaap_MinimumMember
Credit support 1.20%rwt_FairValueInputsCreditSupport
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_ResidentialJumboLoansPricedToWholeLoanMarketUncommittedToSelllMember
/ us-gaap_RangeAxis
= us-gaap_MinimumMember
Residential Jumbo Loans Priced To Whole Loan Market Uncommitted To Selll [Member] | Maximum  
Fair Value Inputs, Assets, Quantitative Information [Line Items]  
Prepayment rate 15.00%us-gaap_FairValueInputsPrepaymentRate
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_ResidentialJumboLoansPricedToWholeLoanMarketUncommittedToSelllMember
/ us-gaap_RangeAxis
= us-gaap_MaximumMember
Credit support 1.70%rwt_FairValueInputsCreditSupport
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_ResidentialJumboLoansPricedToWholeLoanMarketUncommittedToSelllMember
/ us-gaap_RangeAxis
= us-gaap_MaximumMember
Residential Jumbo Loans Priced To Whole Loan Market Uncommitted To Selll [Member] | Weighted Average  
Fair Value Inputs, Assets, Quantitative Information [Line Items]  
Prepayment rate 15.00%us-gaap_FairValueInputsPrepaymentRate
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_ResidentialJumboLoansPricedToWholeLoanMarketUncommittedToSelllMember
/ us-gaap_RangeAxis
= us-gaap_WeightedAverageMember
Credit support 1.27%rwt_FairValueInputsCreditSupport
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_ResidentialJumboLoansPricedToWholeLoanMarketUncommittedToSelllMember
/ us-gaap_RangeAxis
= us-gaap_WeightedAverageMember
Residential Jumbo Loans Priced To Whole Loan Market Committed To Sell  
Fair Value Inputs, Assets, Quantitative Information [Line Items]  
Fair Value 296,096,000us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisWithUnobservableInputs
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_ResidentialJumboLoansPricedToWholeLoanMarketCommittedToSellMember
Residential Jumbo Loans Priced To Whole Loan Market Committed To Sell | Minimum  
Fair Value Inputs, Assets, Quantitative Information [Line Items]  
Committed Sales Price 102rwt_FairValueInputsCommittedSalesPrice
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_ResidentialJumboLoansPricedToWholeLoanMarketCommittedToSellMember
/ us-gaap_RangeAxis
= us-gaap_MinimumMember
Residential Jumbo Loans Priced To Whole Loan Market Committed To Sell | Maximum  
Fair Value Inputs, Assets, Quantitative Information [Line Items]  
Committed Sales Price 103rwt_FairValueInputsCommittedSalesPrice
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_ResidentialJumboLoansPricedToWholeLoanMarketCommittedToSellMember
/ us-gaap_RangeAxis
= us-gaap_MaximumMember
Residential Jumbo Loans Priced To Whole Loan Market Committed To Sell | Weighted Average  
Fair Value Inputs, Assets, Quantitative Information [Line Items]  
Committed Sales Price 103rwt_FairValueInputsCommittedSalesPrice
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_ResidentialJumboLoansPricedToWholeLoanMarketCommittedToSellMember
/ us-gaap_RangeAxis
= us-gaap_WeightedAverageMember
Residential Loans Held For Sale  
Fair Value Inputs, Assets, Quantitative Information [Line Items]  
Fair Value 1,104,000us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisWithUnobservableInputs
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_ResidentialLoansHeldForSaleMember
Residential Loans Held For Sale | Minimum  
Fair Value Inputs, Assets, Quantitative Information [Line Items]  
Loss severity 13.00%us-gaap_FairValueInputsLossSeverity
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_ResidentialLoansHeldForSaleMember
/ us-gaap_RangeAxis
= us-gaap_MinimumMember
Residential Loans Held For Sale | Maximum  
Fair Value Inputs, Assets, Quantitative Information [Line Items]  
Loss severity 30.00%us-gaap_FairValueInputsLossSeverity
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_ResidentialLoansHeldForSaleMember
/ us-gaap_RangeAxis
= us-gaap_MaximumMember
Residential Loans Held For Sale | Weighted Average  
Fair Value Inputs, Assets, Quantitative Information [Line Items]  
Loss severity 20.00%us-gaap_FairValueInputsLossSeverity
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_ResidentialLoansHeldForSaleMember
/ us-gaap_RangeAxis
= us-gaap_WeightedAverageMember
Commercial Loans at Fair Value  
Fair Value Inputs, Assets, Quantitative Information [Line Items]  
Fair Value 237,496,000us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisWithUnobservableInputs
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_CommercialLoansAtFairValueMember
Commercial Loans at Fair Value | Minimum  
Fair Value Inputs, Assets, Quantitative Information [Line Items]  
Credit spread 1.57%rwt_FairValueInputsCreditSpreads
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_CommercialLoansAtFairValueMember
/ us-gaap_RangeAxis
= us-gaap_MinimumMember
Credit support 23.00%rwt_FairValueInputsCreditSupport
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_CommercialLoansAtFairValueMember
/ us-gaap_RangeAxis
= us-gaap_MinimumMember
Commercial Loans at Fair Value | Maximum  
Fair Value Inputs, Assets, Quantitative Information [Line Items]  
Credit spread 1.63%rwt_FairValueInputsCreditSpreads
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_CommercialLoansAtFairValueMember
/ us-gaap_RangeAxis
= us-gaap_MaximumMember
Credit support 25.00%rwt_FairValueInputsCreditSupport
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_CommercialLoansAtFairValueMember
/ us-gaap_RangeAxis
= us-gaap_MaximumMember
Commercial Loans at Fair Value | Weighted Average  
Fair Value Inputs, Assets, Quantitative Information [Line Items]  
Credit spread 1.61%rwt_FairValueInputsCreditSpreads
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_CommercialLoansAtFairValueMember
/ us-gaap_RangeAxis
= us-gaap_WeightedAverageMember
Credit support 24.00%rwt_FairValueInputsCreditSupport
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_CommercialLoansAtFairValueMember
/ us-gaap_RangeAxis
= us-gaap_WeightedAverageMember
Trading and AFS securities  
Fair Value Inputs, Assets, Quantitative Information [Line Items]  
Fair Value 1,379,230,000us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisWithUnobservableInputs
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_InvestmentSecuritiesMember
Trading and AFS securities | Minimum  
Fair Value Inputs, Assets, Quantitative Information [Line Items]  
Discount rate 4.00%us-gaap_FairValueInputsDiscountRate
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_InvestmentSecuritiesMember
/ us-gaap_RangeAxis
= us-gaap_MinimumMember
Prepayment rate 1.00%us-gaap_FairValueInputsPrepaymentRate
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_InvestmentSecuritiesMember
/ us-gaap_RangeAxis
= us-gaap_MinimumMember
Default rate 0.00%us-gaap_FairValueInputsProbabilityOfDefault
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_InvestmentSecuritiesMember
/ us-gaap_RangeAxis
= us-gaap_MinimumMember
Credit support 0.00%rwt_FairValueInputsCreditSupport
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_InvestmentSecuritiesMember
/ us-gaap_RangeAxis
= us-gaap_MinimumMember
Loss severity 20.00%us-gaap_FairValueInputsLossSeverity
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_InvestmentSecuritiesMember
/ us-gaap_RangeAxis
= us-gaap_MinimumMember
Trading and AFS securities | Maximum  
Fair Value Inputs, Assets, Quantitative Information [Line Items]  
Discount rate 12.00%us-gaap_FairValueInputsDiscountRate
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_InvestmentSecuritiesMember
/ us-gaap_RangeAxis
= us-gaap_MaximumMember
Prepayment rate 35.00%us-gaap_FairValueInputsPrepaymentRate
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_InvestmentSecuritiesMember
/ us-gaap_RangeAxis
= us-gaap_MaximumMember
Default rate 35.00%us-gaap_FairValueInputsProbabilityOfDefault
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_InvestmentSecuritiesMember
/ us-gaap_RangeAxis
= us-gaap_MaximumMember
Credit support 48.00%rwt_FairValueInputsCreditSupport
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_InvestmentSecuritiesMember
/ us-gaap_RangeAxis
= us-gaap_MaximumMember
Loss severity 64.00%us-gaap_FairValueInputsLossSeverity
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_InvestmentSecuritiesMember
/ us-gaap_RangeAxis
= us-gaap_MaximumMember
Trading and AFS securities | Weighted Average  
Fair Value Inputs, Assets, Quantitative Information [Line Items]  
Discount rate 6.00%us-gaap_FairValueInputsDiscountRate
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_InvestmentSecuritiesMember
/ us-gaap_RangeAxis
= us-gaap_WeightedAverageMember
Prepayment rate 12.00%us-gaap_FairValueInputsPrepaymentRate
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_InvestmentSecuritiesMember
/ us-gaap_RangeAxis
= us-gaap_WeightedAverageMember
Default rate 8.00%us-gaap_FairValueInputsProbabilityOfDefault
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_InvestmentSecuritiesMember
/ us-gaap_RangeAxis
= us-gaap_WeightedAverageMember
Credit support 5.00%rwt_FairValueInputsCreditSupport
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_InvestmentSecuritiesMember
/ us-gaap_RangeAxis
= us-gaap_WeightedAverageMember
Loss severity 34.00%us-gaap_FairValueInputsLossSeverity
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_InvestmentSecuritiesMember
/ us-gaap_RangeAxis
= us-gaap_WeightedAverageMember
Mortgage Servicing Rights  
Fair Value Inputs, Assets, Quantitative Information [Line Items]  
Fair Value 139,293,000us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisWithUnobservableInputs
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_MortgageServicingRightsMember
Mortgage Servicing Rights | Minimum  
Fair Value Inputs, Assets, Quantitative Information [Line Items]  
Discount rate 8.00%us-gaap_FairValueInputsDiscountRate
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_MortgageServicingRightsMember
/ us-gaap_RangeAxis
= us-gaap_MinimumMember
Prepayment rate 4.00%us-gaap_FairValueInputsPrepaymentRate
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_MortgageServicingRightsMember
/ us-gaap_RangeAxis
= us-gaap_MinimumMember
Per loan annual cost to service 72rwt_FairValueInputsPerLoanAnnualCostToService
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_MortgageServicingRightsMember
/ us-gaap_RangeAxis
= us-gaap_MinimumMember
Mortgage Servicing Rights | Maximum  
Fair Value Inputs, Assets, Quantitative Information [Line Items]  
Discount rate 11.00%us-gaap_FairValueInputsDiscountRate
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_MortgageServicingRightsMember
/ us-gaap_RangeAxis
= us-gaap_MaximumMember
Prepayment rate 60.00%us-gaap_FairValueInputsPrepaymentRate
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_MortgageServicingRightsMember
/ us-gaap_RangeAxis
= us-gaap_MaximumMember
Per loan annual cost to service 82rwt_FairValueInputsPerLoanAnnualCostToService
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_MortgageServicingRightsMember
/ us-gaap_RangeAxis
= us-gaap_MaximumMember
Mortgage Servicing Rights | Weighted Average  
Fair Value Inputs, Assets, Quantitative Information [Line Items]  
Discount rate 10.00%us-gaap_FairValueInputsDiscountRate
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_MortgageServicingRightsMember
/ us-gaap_RangeAxis
= us-gaap_WeightedAverageMember
Prepayment rate 12.00%us-gaap_FairValueInputsPrepaymentRate
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_MortgageServicingRightsMember
/ us-gaap_RangeAxis
= us-gaap_WeightedAverageMember
Per loan annual cost to service 77rwt_FairValueInputsPerLoanAnnualCostToService
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_MortgageServicingRightsMember
/ us-gaap_RangeAxis
= us-gaap_WeightedAverageMember
REO  
Fair Value Inputs, Assets, Quantitative Information [Line Items]  
Fair Value 2,069,000us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisWithUnobservableInputs
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_OtherRealEstateOwnedMember
REO | Minimum  
Fair Value Inputs, Assets, Quantitative Information [Line Items]  
Loss severity 0.00%us-gaap_FairValueInputsLossSeverity
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_OtherRealEstateOwnedMember
/ us-gaap_RangeAxis
= us-gaap_MinimumMember
REO | Maximum  
Fair Value Inputs, Assets, Quantitative Information [Line Items]  
Loss severity 100.00%us-gaap_FairValueInputsLossSeverity
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_OtherRealEstateOwnedMember
/ us-gaap_RangeAxis
= us-gaap_MaximumMember
REO | Weighted Average  
Fair Value Inputs, Assets, Quantitative Information [Line Items]  
Loss severity 39.00%us-gaap_FairValueInputsLossSeverity
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_OtherRealEstateOwnedMember
/ us-gaap_RangeAxis
= us-gaap_WeightedAverageMember
Loan Purchase Commitments  
Fair Value Inputs, Assets, Quantitative Information [Line Items]  
Fair Value 1,119,000us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisWithUnobservableInputs
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_LoanPurchaseCommitmentsMember
[1]
Loan Purchase Commitments | Minimum  
Fair Value Inputs, Assets, Quantitative Information [Line Items]  
MSR Multiple 0rwt_FairValueInputsMortgageServicingRightMultiple
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_LoanPurchaseCommitmentsMember
/ us-gaap_RangeAxis
= us-gaap_MinimumMember
Pullthrough rate 56.00%rwt_FairValueInputsRecoveryRate
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_LoanPurchaseCommitmentsMember
/ us-gaap_RangeAxis
= us-gaap_MinimumMember
Loan Purchase Commitments | Maximum  
Fair Value Inputs, Assets, Quantitative Information [Line Items]  
MSR Multiple 6rwt_FairValueInputsMortgageServicingRightMultiple
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_LoanPurchaseCommitmentsMember
/ us-gaap_RangeAxis
= us-gaap_MaximumMember
Pullthrough rate 99.00%rwt_FairValueInputsRecoveryRate
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_LoanPurchaseCommitmentsMember
/ us-gaap_RangeAxis
= us-gaap_MaximumMember
Loan Purchase Commitments | Weighted Average  
Fair Value Inputs, Assets, Quantitative Information [Line Items]  
MSR Multiple 4rwt_FairValueInputsMortgageServicingRightMultiple
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_LoanPurchaseCommitmentsMember
/ us-gaap_RangeAxis
= us-gaap_WeightedAverageMember
Pullthrough rate 83.00%rwt_FairValueInputsRecoveryRate
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_LoanPurchaseCommitmentsMember
/ us-gaap_RangeAxis
= us-gaap_WeightedAverageMember
Commercial Secured Borrowings  
Fair Value Inputs, Assets, Quantitative Information [Line Items]  
Fair Value 66,707,000us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisWithUnobservableInputs
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_CommercialSecuredLoanMember
Commercial Secured Borrowings | Minimum  
Fair Value Inputs, Assets, Quantitative Information [Line Items]  
Credit spread 1.61%rwt_FairValueInputsCreditSpreads
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_CommercialSecuredLoanMember
/ us-gaap_RangeAxis
= us-gaap_MinimumMember
Credit support 23.00%rwt_FairValueInputsCreditSupport
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_CommercialSecuredLoanMember
/ us-gaap_RangeAxis
= us-gaap_MinimumMember
Commercial Secured Borrowings | Maximum  
Fair Value Inputs, Assets, Quantitative Information [Line Items]  
Credit spread 1.61%rwt_FairValueInputsCreditSpreads
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_CommercialSecuredLoanMember
/ us-gaap_RangeAxis
= us-gaap_MaximumMember
Credit support 23.00%rwt_FairValueInputsCreditSupport
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_CommercialSecuredLoanMember
/ us-gaap_RangeAxis
= us-gaap_MaximumMember
Commercial Secured Borrowings | Weighted Average  
Fair Value Inputs, Assets, Quantitative Information [Line Items]  
Credit spread 1.61%rwt_FairValueInputsCreditSpreads
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_CommercialSecuredLoanMember
/ us-gaap_RangeAxis
= us-gaap_WeightedAverageMember
Credit support 23.00%rwt_FairValueInputsCreditSupport
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_CommercialSecuredLoanMember
/ us-gaap_RangeAxis
= us-gaap_WeightedAverageMember
Residential Jumbo Fixed Rate Loans Priced To Securitization and Whole Loan Market Uncommitted To Sell  
Fair Value Inputs, Assets, Quantitative Information [Line Items]  
Fair Value 1,231,823,000us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisWithUnobservableInputs
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_ResidentialJumboFixedRateLoansPricedToSecuritizationAndWholeLoanMarketUncommittedToSellMember
Guarantee Asset  
Fair Value Inputs, Assets, Quantitative Information [Line Items]  
Fair Value 7,201,000us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisWithUnobservableInputs
/ us-gaap_FairValueByMeasurementFrequencyAxis
= rwt_GuaranteeAssetMember
[1] For the purpose of this presentation loan purchase commitment assets and liabilities are presented net.