Deconsolidation Of Multifamily Asset Backed Securities

No definition available.

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

- Definition

Deconsolidation Of Multifamily Loans Held In Securitizations Trusts

+ References

No definition available.

+ Details

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

- Definition

Number Of Partnerships Consolidated

+ References

No definition available.

+ Details

Name:	rwt_NumberOfPartnershipsConsolidated
Namespace Prefix:	rwt_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of Securitization Entities to which Asset Transferred

+ References

No definition available.

+ Details

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

- Definition

Amount of net assets (liabilities).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 30
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=77885760&loc=SL35686385-199418

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 946
-SubTopic 205
-Section 45
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=118262037&loc=d3e9915-115836

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 946
-SubTopic 220
-Section S99
-Paragraph 3
-Subparagraph (SX 210.6-09(7))
-URI http://asc.fasb.org/extlink&oid=116637345&loc=SL114874367-224272

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 946
-SubTopic 210
-Section S99
-Paragraph 2
-Subparagraph (SX 210.6-05(4))
-URI http://asc.fasb.org/extlink&oid=6488278&loc=d3e604008-122996

Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 946
-SubTopic 220
-Section S99
-Paragraph 3
-Subparagraph (SX 210.6-09(6))
-URI http://asc.fasb.org/extlink&oid=116637345&loc=SL114874367-224272

+ Details

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

- Definition

Amount of gain (loss) from deconsolidation of subsidiary and derecognition of group of assets constituting transfer of business or nonprofit activity, excluding conveyance of oil and gas mineral rights and transfer of good or service in contract with customer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 50
-Paragraph 1B
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109239629&loc=SL4582445-111684

+ Details

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

- Definition

Fair value of an asset representing net future revenue from contractually specified servicing fees, late charges, and other ancillary revenues, in excess of future costs related to servicing arrangements.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-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 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 50
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=116651436&loc=d3e122625-111746

+ Details

Name:	us-gaap_ServicingAssetAtFairValueAmount
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_VariableInterestEntityLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of the Variable Interest Entity's (VIE) voting interest owned by (or beneficial interest in) the reporting entity (directly or indirectly).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 50
-Paragraph 5A
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=118582676&loc=SL6759159-111685

+ Details

Name:	us-gaap_VariableInterestEntityOwnershipPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	rwt_InvestmentsbyConsolidatedandNonconsolidatedEntitiesAxis=us-gaap_VariableInterestEntityNotPrimaryBeneficiaryMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

Name:	rwt_InvestmentsbyConsolidatedandNonconsolidatedEntitiesAxis=us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

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

- Details

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

- Details

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

- Details

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

Principles of Consolidation - Additional Information (Details) $ in Thousands	3 Months Ended			12 Months Ended
	Mar. 31, 2020 USD ($) entity	Mar. 31, 2019 USD ($)	Dec. 31, 2018 partnership	Dec. 31, 2018 USD ($)	Dec. 31, 2019 USD ($)
Variable Interest Entity [Line Items]
Number of partnerships consolidated \| partnership			2
VIE, ownership interest rate	80.00%
MSRs	$ 282,743				$ 151,582
Consolidation of multifamily loans held in securitization trusts	3,849,779	$ 0
Consolidation of multifamily ABS	$ 3,706,789	$ 0
Deconsolidation, realized market valuation gain (loss)				$ (72,000)
Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity [Line Items]
Number of securitization entities to which asset transferred (in entities) \| entity	51
Legacy Sequoia \| Variable Interest Entity, Primary Beneficiary
Variable Interest Entity [Line Items]
Estimated fair value of investments	$ 6,000
Sequoia Choice \| Variable Interest Entity, Primary Beneficiary
Variable Interest Entity [Line Items]
Estimated fair value of investments	144,000
Freddie Mac SLST \| Variable Interest Entity, Primary Beneficiary
Variable Interest Entity [Line Items]
Estimated fair value of investments	309,000
Freddie Mac K-Series \| Variable Interest Entity, Primary Beneficiary
Variable Interest Entity [Line Items]
Estimated fair value of investments	23,000
CoreVest \| Variable Interest Entity, Primary Beneficiary
Variable Interest Entity [Line Items]
Estimated fair value of investments	170,000
Servicing Investment \| Variable Interest Entity, Primary Beneficiary
Variable Interest Entity [Line Items]
MSRs	$ 59,000