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4us-gaap_VariableInterestEntityEntityMaximumLossExposureAmountus-gaap_truecreditinstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse442380000442380[1]USD$falsetruefalse2truefalsefalse124090000124090[1]USD$falsetruefalsexbrli:monetaryItemTypemonetaryThe reporting entity's maximum amount of exposure to loss as a result of its involvement with the Variable Interest Entity (VIE).Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 50 -Paragraph 4 -Subparagraph b -URI http://asc.fasb.org/extlink&oid=28200181&loc=d3e5728-111685 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 50 -Paragraph 6 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=28200181&loc=d3e5747-111685 false2Maximum loss exposure3false 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5us-gaap_VariableInterestEntityNonconsolidatedCarryingAmountAssetsus-gaap_truedebitinstantfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1truefalsefalse123591000123591USD$falsefalsefalse2truefalsefalse1040900010409USD$falsefalsefalsexbrli:monetaryItemTypemonetaryCarrying amount of the assets in the reporting entity's statement of financial position that relate to the reporting entity's variable interest in the Variable Interest Entity (VIE), where the reporting entity is not the VIE's primary beneficiary.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 50 -Paragraph 4 -Subparagraph a -URI http://asc.fasb.org/extlink&oid=28200181&loc=d3e5728-111685 false2Securities7false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse5false USDtruefalse$eol_PE798-----1310-Q0007_STD_0_20130630_0_708088x710699_710256x838995http://www.sec.gov/CIK0000930236instant2013-06-30T00:00:000001-01-01T00:00:00falsefalseVariable Interest Entity, Not Primary Beneficiaryus-gaap_VariableInterestEntitiesByClassificationOfEntityAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_VariableInterestEntityNotPrimaryBeneficiaryMemberus-gaap_VariableInterestEntitiesByClassificationOfEntityAxisexplicitMemberfalsefalseSubordinate Securitiesus-gaap_InvestmentTypeAxisxbrldihttp://xbrl.org/2006/xbrldirwt_SubordinateSecuritiesMemberus-gaap_InvestmentTypeAxisexplicitMemberiso4217_USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$nanafalse0Subordinate Securities8true 4us-gaap_AssetsFairValueDisclosureAbstractus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0On-balance sheet assets, at fair value:9false 5us-gaap_VariableInterestEntityNonconsolidatedCarryingAmountAssetsus-gaap_truedebitinstantfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1truefalsefalse318789000318789USD$falsetruefalse2truefalsefalse113681000113681USD$falsetruefalsexbrli:monetaryItemTypemonetaryCarrying amount of the assets in the reporting entity's statement of financial position that relate to the reporting entity's variable interest in the Variable Interest Entity (VIE), where the reporting entity is not the VIE's primary beneficiary.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 50 -Paragraph 4 -Subparagraph a -URI http://asc.fasb.org/extlink&oid=28200181&loc=d3e5728-111685 false2Securities1Maximum loss exposure from our involvement with unconsolidated VIEs pertains to the carrying value of our securities retained from these VIEs and represents estimated losses that would be incurred under severe, hypothetical circumstances, such as if the value of our interests and any associated collateral declines to zero. This does not include, for example, any potential exposure to representation and warranty claims associated with our initial transfer of loans into a securitization.falseSummary of Unconsolidated Variable Interest Entity's Sponsored by Redwood (Detail) (Variable Interest Entity, Not Primary Beneficiary, USD $)ThousandsUnKnownUnKnownUnKnowntruefalsefalseSheethttp://www.redwoodtrust.com/taxonomy/role/DisclosureSummaryOfUnconsolidatedVariableInterestEntitysSponsoredByRedwood29