Fair Value, Option, Loans Held As Assets, Aggregate Amount In Foreclosure

No definition available.

Name:	rwt_FairValueOptionLoansHeldAsAssetsAggregateAmountInForeclosure
Namespace Prefix:	rwt_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The weighted average FICO score for borrowers at the time loans were originated.

+ References

No definition available.

+ Details

Name:	rwt_FinancingReceivableCreditScoreFICOWeightedAverage
Namespace Prefix:	rwt_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	instant

- Definition

Financing Receivable, Loan To Value Ratio

+ References

No definition available.

+ Details

Name:	rwt_FinancingReceivableLoanToValueRatio
Namespace Prefix:	rwt_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Financing Receivable, Number Of Loans In Foreclosure

+ References

No definition available.

+ Details

Name:	rwt_FinancingReceivableNumberOfLoansInForeclosure
Namespace Prefix:	rwt_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Financing Receivable, Number Of Loans Past Due

+ References

No definition available.

+ Details

Name:	rwt_FinancingReceivableNumberOfLoansPastDue
Namespace Prefix:	rwt_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Financing Receivables, Weighted Average Interest Rate

+ References

No definition available.

+ Details

Name:	rwt_FinancingReceivablesWeightedAverageInterestRate
Namespace Prefix:	rwt_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Loans Receivable, Percentage Bearing Fixed Interest, Percentage Rate

+ References

No definition available.

+ Details

Name:	rwt_LoansReceivablePercentageBearingFixedInterestPercentageRate
Namespace Prefix:	rwt_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Percentage Of Loan Portfolio

+ References

No definition available.

+ Details

Name:	rwt_PercentageOfLoanPortfolio
Namespace Prefix:	rwt_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Principal Balance of Loans Acquired During Period

+ References

No definition available.

+ Details

Name:	rwt_PrincipalBalanceOfLoansAcquiredDuringPeriod
Namespace Prefix:	rwt_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Principal Balance of Loans Sold During Period

+ References

No definition available.

+ Details

Name:	rwt_PrincipalBalanceofLoansSoldDuringPeriod
Namespace Prefix:	rwt_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

For each line item in the statement of financial position, the amounts of gains and losses from fair value changes included in earnings.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 30
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6957238&loc=d3e14172-108612

+ Details

Name:	us-gaap_FairValueOptionChangesInFairValueGainLoss1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

This item represents the aggregate fair value of loans held as assets that are 90 days or more past due for which the fair value option has been elected.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 28
-Subparagraph (e)(1)
-URI http://asc.fasb.org/extlink&oid=6957238&loc=d3e14064-108612

+ Details

Name:	us-gaap_FairValueOptionLoansHeldAsAssets90DaysOrMorePastDue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of the collateral pledged in support of federal home loan bank advances outstanding.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6479118&loc=d3e64650-112822

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
-Paragraph 3
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=6479336&loc=d3e64711-112823

+ Details

Name:	us-gaap_FederalHomeLoanBankAdvancesGeneralDebtObligationsDisclosuresCollateralPledged1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount after allowance and deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of consumer loans, including, but not limited to, mortgage, home equity, vehicles, credit card, installment, and lease financing. Excludes loans and leases covered under loss sharing agreements.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=49124121&loc=d3e5066-111524

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=49124121&loc=d3e5074-111524

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=28367877&loc=d3e4428-111522

+ Details

Name:	us-gaap_LoansAndLeasesReceivableNetReportedAmountConsumer
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Carrying amount as of the balance sheet date of loans that have been pledged as collateral for borrowings. If the secured party has the right by contract or custom to sell or re-pledge the collateral, then the debtor reclassifies that asset and report that asset in its statement of financial position separately from other assets not so encumbered.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 30
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6467456&loc=d3e113888-111728

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=49124121&loc=d3e5086-111524

+ Details

Name:	us-gaap_LoansPledgedAsCollateral
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- 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_MortgageLoansOnRealEstateLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Indicates the number of mortgages under each classification.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 948
-SubTopic 310
-Section S99
-Paragraph 1
-Subparagraph (SX 210.12-29.3)
-URI http://asc.fasb.org/extlink&oid=6589523&loc=d3e617274-123014

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 10
-Section S99
-Paragraph 6
-Subparagraph (SX 210.5-04.(c) Schedule IV)
-URI http://asc.fasb.org/extlink&oid=27047687&loc=d3e5864-122674

+ Details

Name:	us-gaap_MortgageLoansOnRealEstateNumberOfLoans
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

The total periodic movement (increases and decreases) in the carrying amount of mortgage loans on real estate.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 948
-SubTopic 310
-Section S99
-Paragraph 1
-Subparagraph (SX 210.12-29.6)
-URI http://asc.fasb.org/extlink&oid=6589523&loc=d3e617274-123014

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 10
-Section S99
-Paragraph 6
-Subparagraph (SX 210.5-04.(c) Schedule IV)
-URI http://asc.fasb.org/extlink&oid=27047687&loc=d3e5864-122674

+ Details

Name:	us-gaap_MortgageLoansOnRealEstatePeriodIncreaseDecrease
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	duration

- Definition

This is the sum of principal amount outstanding for both securitized and unsecuritized loans of all types.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=51814546&loc=d3e107314-111719

+ Details

Name:	us-gaap_PrincipalAmountOutstandingOnLoansManagedAndSecuritized
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amortized amount of contract to service financial assets under which the benefits of servicing are expected to more than adequately compensate the servicer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 50
-Section 25
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=7524895&loc=d3e120260-111741

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 50
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6469459&loc=d3e122492-111745

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 50
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6469459&loc=d3e122501-111745

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 50
-Section 50
-Paragraph 4
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=56950315&loc=d3e122739-111746

+ Details

Name:	us-gaap_ServicingAssetAtAmortizedValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Value of loans held-for-sale transferred to loans held in the entity's portfolio in noncash transactions.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=6367179&loc=d3e4313-108586

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=6367179&loc=d3e4304-108586

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=6367179&loc=d3e4332-108586

+ Details

Name:	us-gaap_TransferOfLoansHeldForSaleToPortfolioLoans1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Value of loans and leases held in the entity's portfolio transferred to loans and leases held-for-sale in noncash transactions.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=6367179&loc=d3e4304-108586

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=6367179&loc=d3e4332-108586

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=6367179&loc=d3e4313-108586

+ Details

Name:	us-gaap_TransferOfPortfolioLoansAndLeasesToHeldForSale1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_FixedRateResidentialMortgageMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FederalHomeLoanBankAdvancesBranchOfFHLBBankAxis=us-gaap_FederalHomeLoanBankOfChicagoMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentsOwnedAndPledgedAsCollateralAxis=us-gaap_ResidentialMortgageMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=rwt_SequoiaSecuritizationEntitiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=us-gaap_ParentCompanyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=rwt_ResidentialLoansAtFairValueMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_MortgageLoansOnRealEstateLoanTypeAxis=rwt_JumboLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablesPeriodPastDueAxis=us-gaap_FinancingReceivablesEqualToGreaterThan90DaysPastDueMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablesPeriodPastDueAxis=rwt_FinancingReceivablesReceivablesInForeclosureMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=rwt_ResidentialLoansAtLowerOfCostOrFairValueMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=rwt_ResidentialLoansHeldForInvestmentAtFairValueMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=rwt_HybridOrARMLoansMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis=rwt_OriginatedBetweenTwentyThirteenAndTwentySixteenMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis=rwt_OriginatedDuringTwentyTwelveAndPriorYearsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_InvestmentTypeAxis=rwt_MortgageServicingRightsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Residential Loans - Additional Information (Details) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2016 USD ($) loan	Sep. 30, 2015 USD ($)	Sep. 30, 2016 USD ($) loan	Sep. 30, 2015 USD ($)	Dec. 31, 2015 USD ($) Contract loan
Mortgage Loans on Real Estate [Line Items]
Carrying value of loans	$ 4,311,164		$ 4,311,164		$ 3,928,803
Transfers from loans held-for-sale to loans held-for-investment			877,744	$ 964,013
Transfers from loans held-for-investment to loans held-for-sale			$ 359,005	66,918
Fixed-rate loans
Mortgage Loans on Real Estate [Line Items]
Weighted average coupon rate (percent)	4.13%		4.13%
FHLB Chicago \| Held-for-sale residential loans
Mortgage Loans on Real Estate [Line Items]
Loans pledged as collateral under borrowing agreement with FHLBC	$ 2,270,000		$ 2,270,000
Sequoia Entities
Mortgage Loans on Real Estate [Line Items]
Carrying value of loans	839,976		839,976		1,021,870
Redwood
Mortgage Loans on Real Estate [Line Items]
Carrying value of loans	3,471,188		$ 3,471,188		$ 2,906,933
Residential Loans
Mortgage Loans on Real Estate [Line Items]
Number of loans \| loan			1,528		1,763
Loan Principal	1,160,000		$ 1,160,000		$ 1,090,000
Carrying value of loans	1,190,000		1,190,000		1,110,000
Principal value of loans purchased	1,220,000	$ 2,910,000	3,730,000	8,090,000
Principal balance of loans sold during period	755,000	2,070,000	2,800,000	7,000,000
Valuation adjustments	1,000	(11,000)	12,000	(10,000)
Loan pledged as collateral	941,000		941,000
Loans held-for-investment, in foreclosure	1,000		1,000
Residential Loans \| Jumbo Loan
Mortgage Loans on Real Estate [Line Items]
Carrying value of loans	1,187,240		1,187,240		984,486
Residential Loans \| Jumbo Loan \| Sequoia Entities
Mortgage Loans on Real Estate [Line Items]
Carrying value of loans	0		0		0
Residential Loans \| Jumbo Loan \| Redwood
Mortgage Loans on Real Estate [Line Items]
Carrying value of loans	$ 1,187,240		$ 1,187,240		984,486
Residential Loans \| Financing Receivables, Equal to Greater than 90 Days Past Due
Mortgage Loans on Real Estate [Line Items]
Carrying value of loans					$ 1,000
Number of loans past due \| loan	0		0		1
Number of loans in foreclosure \| loan					1
Residential Loans \| Financing Receivables, Receivables In Foreclosure
Mortgage Loans on Real Estate [Line Items]
Carrying value of loans					$ 1,000
Residential loans, at lower of cost or fair value
Mortgage Loans on Real Estate [Line Items]
Number of loans \| loan			8		9
Loan Principal	$ 2,000		$ 2,000		$ 2,000
Carrying value of loans	1,274		1,274		$ 1,433
Number of loans in foreclosure \| loan					1
Loans held-for-investment, delinquent greater than 90 days	400		400		$ 400
Loans held-for-investment, in foreclosure	100		100		100
Residential loans, at lower of cost or fair value \| Sequoia Entities
Mortgage Loans on Real Estate [Line Items]
Carrying value of loans	0		0		0
Residential loans, at lower of cost or fair value \| Redwood
Mortgage Loans on Real Estate [Line Items]
Carrying value of loans	$ 1,274		$ 1,274		$ 1,433
Residential loans, at lower of cost or fair value \| Financing Receivables, Equal to Greater than 90 Days Past Due
Mortgage Loans on Real Estate [Line Items]
Number of loans past due \| loan	1		1		1
Residential Loans Held For Investment at Fair Value
Mortgage Loans on Real Estate [Line Items]
Number of loans \| loan			3,056		2,398
Loan Principal	$ 2,210,000		$ 2,210,000		$ 1,760,000
Carrying value of loans					$ 1,790,000
Valuation adjustments	(1,000)	9,000	22,000	5,000
Transfers from loans held-for-sale to loans held-for-investment	152,000	300,000	878,000	962,000
Transfers from loans held-for-investment to loans held-for-sale	$ 0	67,000	$ 56,000
Weighted average original Fair Isaac Corporation (FICO) score	773		773
Weighted average original loan-to-value (LTV) (percent)	66.00%		66.00%
Percentage of fixed-rate loans	99.50%		99.50%
Residential Loans Held For Investment at Fair Value \| Hybrid loans
Mortgage Loans on Real Estate [Line Items]
Weighted average coupon rate (percent)	3.83%		3.83%
Residential Loans Held For Investment at Fair Value \| Originated Between 2013 and 2016
Mortgage Loans on Real Estate [Line Items]
Percentage of loan portfolio originated in year	93.00%		93.00%
Residential Loans Held For Investment at Fair Value \| Originated 2012 and prior years
Mortgage Loans on Real Estate [Line Items]
Percentage of loan portfolio originated in year	7.00%		7.00%
Residential Loans Held For Investment at Fair Value \| Sequoia Entities
Mortgage Loans on Real Estate [Line Items]
Number of loans			3,901		4,545
Loan Principal	$ 943,000		$ 943,000		$ 1,120,000
Carrying value of loans	840,000		840,000		1,020,000
Loans held-for-investment, delinquent greater than 90 days	19,000		19,000		27,000
Loans held-for-investment, in foreclosure	$ 18,000		$ 18,000		32,000
Weighted average original Fair Isaac Corporation (FICO) score	728		728
Weighted average original loan-to-value (LTV) (percent)	66.00%		66.00%
Valuation adjustments	$ 9,000	$ (400)	$ (19,000)	$ 5,000
Residential Loans Held For Investment at Fair Value \| Jumbo Loan
Mortgage Loans on Real Estate [Line Items]
Carrying value of loans	3,122,650		3,122,650		2,813,065
Residential Loans Held For Investment at Fair Value \| Jumbo Loan \| Sequoia Entities
Mortgage Loans on Real Estate [Line Items]
Carrying value of loans	839,976		839,976		1,021,870
Residential Loans Held For Investment at Fair Value \| Jumbo Loan \| Redwood
Mortgage Loans on Real Estate [Line Items]
Carrying value of loans	2,282,674		2,282,674		$ 1,791,195
MSRs
Mortgage Loans on Real Estate [Line Items]
Mortgage servicing rights, at amortized cost	$ 2,580,000		$ 2,580,000