Financing Receivable, Contract Maturities

No definition available.

Name:	rwt_FinancingReceivableContractMaturities
Namespace Prefix:	rwt_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- 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:	dtr-types:percentItemType
Balance Type:	na
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:	srt_MortgageLoansOnRealEstateLineItems
Namespace Prefix:	srt_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of mortgage loans within investment in mortgage loan on real estate by entity with substantial portion of business acquiring and holding investment real estate or interest in real estate.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 12
-Footnote 3
-Subsection 29

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 948
-SubTopic 310
-Section S99
-Paragraph 1
-Subparagraph (SX 210.12-29(Footnote 3))
-URI https://asc.fasb.org/extlink&oid=120402547&loc=d3e617274-123014

+ Details

Name:	srt_MortgageLoansOnRealEstateNumberOfLoans
Namespace Prefix:	srt_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of increase (decrease) in investment in mortgage loan on real estate by entity with substantial portion of business acquiring and holding investment real estate or interest in real estate.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 948
-SubTopic 310
-Section S99
-Paragraph 1
-Subparagraph (SX 210.12-29(Footnote 6))
-URI https://asc.fasb.org/extlink&oid=120402547&loc=d3e617274-123014

+ Details

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

- Definition

Amortized cost, after allowance for credit loss, of financing receivable. Excludes financing receivable covered under loss sharing agreement and net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 5
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=124255953&loc=SL82919230-210447

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 45
-Paragraph 2
-URI https://asc.fasb.org/extlink&oid=124259787&loc=d3e4428-111522

+ Details

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

- Definition

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

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=121570589&loc=d3e107314-111719

+ Details

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

- Details

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

- Details

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

- Details

Name:	dei_LegalEntityAxis=rwt_RedwoodTrustInc.Member
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:

Consolidated Agency Multifamily Loans (Details) - Consolidated Agency multifamily loans, at fair value $ in Thousands	3 Months Ended			6 Months Ended		12 Months Ended
	Jun. 30, 2022 USD ($) loan	Mar. 31, 2022	Jun. 30, 2021 USD ($)	Jun. 30, 2022 USD ($) loan	Jun. 30, 2021 USD ($)	Dec. 31, 2021 USD ($) loan
Held-for-investment at fair value
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Net market valuation gain (loss) \| $	$ (6,748)		$ (2,528)	$ (26,429)	$ (3,258)
Redwood
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Number of loans \| loan				28		28
Unpaid principal balance \| $	451,197			$ 451,197		$ 455,168
Fair value of loans \| $	$ 443,114			$ 443,114		$ 473,514
Weighted average coupon rate (as a percent)	4.25%			4.25%		4.25%
Weighted average remaining loan term (years)		4 years		3 years
Number of loans in foreclosure \| loan	0			0		0
Redwood \| Financing Receivables, Equal to Greater than 90 Days Past Due
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Number of loans with 90+ day delinquencies \| loan	0			0		0