2.4.0.81108 - Disclosure - Equity Compensation Plans - Additional Information (Detail)truefalsefalse1false falsefalseeol_PE798-----1310-Q0007_STD_91_20130630_0_713115x769776http://www.sec.gov/CIK0000930236duration2013-04-01T00:00:002013-06-30T00:00:00sharesStandardhttp://www.xbrl.org/2003/instanceshares02false falsefalseeol_PE798-----1310-Q0007_STD_181_20130630_0_713115x769776http://www.sec.gov/CIK0000930236duration2013-01-01T00:00:002013-06-30T00:00:00sharesStandardhttp://www.xbrl.org/2003/instanceshares03false falsefalseeol_PE798-----1310-Q0007_STD_366_20121231_0_713115x769776http://www.sec.gov/CIK0000930236duration2012-01-01T00:00:002012-12-31T00:00:00sharesStandardhttp://www.xbrl.org/2003/instanceshares01true 3us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItemsus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Share-based Compensation Arrangement by Share-based Payment Award [Line Items]2false 4us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrantus-gaap_truenainstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse18311091831109falsefalsefalse2truefalsefalse18311091831109falsefalsefalse3truefalsefalse666610666610falsefalsefalsexbrli:sharesItemTypesharesThe difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 false1Shares of common stock available for grant under Redwood's Incentive Plan3false 4us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedus-gaap_truedebitinstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse1542700015427000USD$falsetruefalse2truefalsefalse1542700015427000USD$falsetruefalse3truefalsefalse2168400021684000USD$falsetruefalsexbrli:monetaryItemTypemonetaryUnrecognized cost of unvested share-based compensation awards.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (i) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 false2Unrecognized compensation cost4false 4us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingNumberus-gaap_truenainstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse190801190801falsefalsefalse2truefalsefalse190801190801falsefalsefalse3truefalsefalse287516287516falsefalsefalsexbrli:sharesItemTypesharesAs of the balance sheet date, the number of shares into which fully vested and expected to vest stock options outstanding can be converted under the option plan.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (e)(1) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 false1Number of fully vested stock options outstanding5false 4us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpirationsInPeriodus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2truefalsefalse9671596715falsefalsefalse3falsefalsefalse00falsefalsefalsexbrli:sharesItemTypesharesNumber of options or other stock instruments for which the right to exercise has lapsed under the terms of the plan agreements.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1)(iv)(4) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 false1Options Expired6false 4rwt_EmployeeStockPurchasePlanNumberOfSharesPurchasedByEmployeerwt_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2truefalsefalse227043227043falsefalsefalse3truefalsefalse207031207031falsefalsefalsexbrli:sharesItemTypesharesAmount of shares of common stock purchased by employees under the Employee Stock Purchase Plan in the current period.No definition available.false1Number of shares purchased by employees7false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse3false truefalseeol_PE798-----1310-Q0007_STD_181_20130630_0_711502x711169http://www.sec.gov/CIK0000930236duration2013-01-01T00:00:002013-06-30T00:00:00falsefalseMinimumus-gaap_RangeAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_MinimumMemberus-gaap_RangeAxisexplicitMembernanafalse0Minimum8true 3us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItemsus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Share-based Compensation Arrangement by Share-based Payment Award [Line Items]9false 4us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1us-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse003 yearsfalsefalsefalse3falsefalsefalse00falsefalsefalsexbrli:durationItemTypenaPeriod which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 false0Share-based compensation, vesting period10false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4false truefalseeol_PE798-----1310-Q0007_STD_181_20130630_0_711502x716112http://www.sec.gov/CIK0000930236duration2013-01-01T00:00:002013-06-30T00:00:00falsefalseMaximumus-gaap_RangeAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_MaximumMemberus-gaap_RangeAxisexplicitMembersharesStandardhttp://www.xbrl.org/2003/instanceshares0nanafalse0Maximum11true 3us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItemsus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Share-based Compensation Arrangement by Share-based Payment Award [Line Items]12false 4us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1us-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse002 yearsfalsefalsefalse3falsefalsefalse00falsefalsefalsexbrli:durationItemTypenaWeighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (i) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 false0Weighted average amortization period remaining for equity awards13false 4us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1us-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse004 yearsfalsefalsefalse3falsefalsefalse00falsefalsefalsexbrli:durationItemTypenaPeriod which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 false0Share-based compensation, vesting period14false 4rwt_EmployeeStockPurchasePlanNumberOfSharesAuthorizedrwt_falsenainstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse450000450000falsefalsefalse2truefalsefalse450000450000falsefalsefalse3falsefalsefalse00falsefalsefalsexbrli:sharesItemTypesharesMaximum amount of shares of common stock permitted to be purchased for all employees under the Employee Stock Purchase Plan.No definition available.false1Shares of common stock to be purchased in aggregate for all employees15false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse5false truefalseeol_PE798-----1310-Q0007_STD_91_20130630_0_713115x716908http://www.sec.gov/CIK0000930236duration2013-04-01T00:00:002013-06-30T00:00:00falsefalseRestricted Stockus-gaap_AwardTypeAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_RestrictedStockMemberus-gaap_AwardTypeAxisexplicitMembersharesStandardhttp://www.xbrl.org/2003/instanceshares0nanafalse0Restricted Stock16true 3us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItemsus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Share-based Compensation Arrangement by Share-based Payment Award [Line Items]17false 4us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumberus-gaap_truenainstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse132802132802falsefalsefalse2truefalsefalse132802132802falsefalsefalse3truefalsefalse190088190088falsefalsefalsexbrli:sharesItemTypesharesThe number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(2)(i)-(ii) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 false1Unvested outstanding stock awards18false 4us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse10961096falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalsexbrli:sharesItemTypesharesThe number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(2)(iii)(1) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 false1Number of stock awards granted19false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse7false truefalseeol_PE798-----1310-Q0007_STD_91_20130630_0_713115x769776http://www.sec.gov/CIK0000930236duration2013-04-01T00:00:002013-06-30T00:00:00falsefalseDeferred Stock Unitsus-gaap_AwardTypeAxisxbrldihttp://xbrl.org/2006/xbrldirwt_DeferredStockUnitsMemberus-gaap_AwardTypeAxisexplicitMembersharesStandardhttp://www.xbrl.org/2003/instanceshares0nanafalse0Deferred Stock Units20true 3us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItemsus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Share-based Compensation Arrangement by Share-based Payment Award [Line Items]21false 4us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumberus-gaap_truenainstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse20244462024446falsefalsefalse2truefalsefalse20244462024446falsefalsefalse3truefalsefalse23612852361285falsefalsefalsexbrli:sharesItemTypesharesThe number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(2)(i)-(ii) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 false1Unvested outstanding stock awards22false 4us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse3101131011falsefalsefalse2truefalsefalse232794232794falsefalsefalse3falsefalsefalse00falsefalsefalsexbrli:sharesItemTypesharesThe number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(2)(iii)(1) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 false1Number of stock awards granted23false 4us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2truefalsefalse10885691088569falsefalsefalse3truefalsefalse11197531119753falsefalsefalsexbrli:sharesItemTypesharesThe number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(2)(iii)(2) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 false1Number of stock awards vested24false 4us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriodus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse3038430384falsefalsefalse2truefalsefalse3038430384falsefalsefalse3falsefalsefalse00falsefalsefalsexbrli:sharesItemTypesharesThe number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1)(iv)(3) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 false1Forfeited stock awards25false 4rwt_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsDistributedInPeriodrwt_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2truefalsefalse539250539250falsefalsefalse3falsefalsefalse00falsefalsefalsexbrli:sharesItemTypesharesShare Based Compensation Arrangement by Share Based Payment Award, Equity Instruments Other Than Options, Distributed in PeriodNo definition available.false1Deferred stock unit distributions26false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse10false USDtruefalse$eol_PE798-----1310-Q0007_STD_0_20130630_0_711502x716112_713115x769776http://www.sec.gov/CIK0000930236instant2013-06-30T00:00:000001-01-01T00:00:00falsefalseDeferred Stock Unitsus-gaap_AwardTypeAxisxbrldihttp://xbrl.org/2006/xbrldirwt_DeferredStockUnitsMemberus-gaap_AwardTypeAxisexplicitMemberfalsefalseMaximumus-gaap_RangeAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_MaximumMemberus-gaap_RangeAxisexplicitMemberiso4217_USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$nanafalse0Deferred Stock Units | Maximum27true 3us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItemsus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Share-based Compensation Arrangement by Share-based Payment Award [Line Items]28false 4us-gaap_DeferredCompensationArrangementWithIndividualDistributionsPaidus-gaap_truedebitinstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse10000001000000USD$falsetruefalse2truefalsefalse10000001000000USD$falsetruefalse3falsefalsefalse00falsefalsefalsexbrli:monetaryItemTypemonetaryThe amount of distributions made to the individual during the period.No definition available.false2Cash distributions to participants in the Executive Deferred Compensation Plan29false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse11false truefalseeol_PE798-----1310-Q0007_STD_91_20130630_0_713115x707592http://www.sec.gov/CIK0000930236duration2013-04-01T00:00:002013-06-30T00:00:00falsefalsePerformance Stock Unitsus-gaap_AwardTypeAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_PerformanceSharesMemberus-gaap_AwardTypeAxisexplicitMembersharesStandardhttp://www.xbrl.org/2003/instanceshares0nanafalse0Performance Stock Units30true 3us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItemsus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Share-based Compensation Arrangement by Share-based Payment Award [Line Items]31false 4us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumberus-gaap_truenainstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse762375762375falsefalsefalse2truefalsefalse762375762375falsefalsefalse3truefalsefalse837737837737falsefalsefalsexbrli:sharesItemTypesharesThe number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(2)(i)-(ii) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 false1Unvested outstanding stock awards32false 4us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriodus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse7536275362falsefalsefalse2truefalsefalse7536275362falsefalsefalse3falsefalsefalse00falsefalsefalsexbrli:sharesItemTypesharesThe number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1)(iv)(3) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 false1Forfeited stock awards33false 4us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1us-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse003 yearsfalsefalsefalse3falsefalsefalse00falsefalsefalsexbrli:durationItemTypenaPeriod which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 false0Share-based compensation, vesting period34false 4us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingRightsus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00The number of underlying shares of our common stock that will vest during 2013 and in future years will vary between 0% (if Three-Year TSR is negative) and 200% (if Three-Year TSR is greater than or equal to 125%) of the number of these PSUs originally granted, adjusted upward (if vesting is greater than 0%) to reflect the value of dividends paid during the three-year vesting period.falsefalsefalse3falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringDescription of award terms as to how many shares or portion of an award are no longer contingent on satisfaction of either a service condition, market condition or a performance condition, thereby giving the employee the legal right to convert the award to shares, to sell the shares, and be entitled to the cash proceeds of such sale. For example, vesting may be expressed as being 25 percent of the shares under option on each anniversary of the grant date.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 false0Underlying shares of vesting common stock vesting description35false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse14false truefalseeol_PE798-----1310-Q0007_STD_181_20130630_0_711502x711169_713115x707592http://www.sec.gov/CIK0000930236duration2013-01-01T00:00:002013-06-30T00:00:00falsefalsePerformance Stock Unitsus-gaap_AwardTypeAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_PerformanceSharesMemberus-gaap_AwardTypeAxisexplicitMemberfalsefalseMinimumus-gaap_RangeAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_MinimumMemberus-gaap_RangeAxisexplicitMemberpureStandardhttp://www.xbrl.org/2003/instancepure0nanafalse0Performance Stock Units | Minimum36true 3us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItemsus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Share-based Compensation Arrangement by Share-based Payment Award [Line Items]37false 4us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentageus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2truetruefalse0.000.00falsefalsefalse3falsefalsefalse00falsefalsefalsenum:percentItemTypepurePercentage of vesting of share-based compensation awards.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 false0Underlying shares of common stock, vesting percentage38false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse15false truefalseeol_PE798-----1310-Q0007_STD_181_20130630_0_711502x716112_713115x707592http://www.sec.gov/CIK0000930236duration2013-01-01T00:00:002013-06-30T00:00:00falsefalsePerformance Stock Unitsus-gaap_AwardTypeAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_PerformanceSharesMemberus-gaap_AwardTypeAxisexplicitMemberfalsefalseMaximumus-gaap_RangeAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_MaximumMemberus-gaap_RangeAxisexplicitMemberpureStandardhttp://www.xbrl.org/2003/instancepure0nanafalse0Performance Stock Units | Maximum39true 3us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItemsus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Share-based Compensation Arrangement by Share-based Payment Award [Line Items]40false 4us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentageus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2truetruefalse2.002.00falsefalsefalse3falsefalsefalse00falsefalsefalsenum:percentItemTypepurePercentage of vesting of share-based compensation awards.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 false0Underlying shares of common stock, vesting percentage41false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse16false truefalseeol_PE798-----1310-Q0007_STD_181_20130630_0_713115x707592_755443x829211http://www.sec.gov/CIK0000930236duration2013-01-01T00:00:002013-06-30T00:00:00falsefalsePerformance Stock Unitsus-gaap_AwardTypeAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_PerformanceSharesMemberus-gaap_AwardTypeAxisexplicitMemberfalsefalse2020rwt_PeriodAxisxbrldihttp://xbrl.org/2006/xbrldirwt_PeriodOneMemberrwt_PeriodAxisexplicitMembernanafalse0Performance Stock Units | 202042true 3us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItemsus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Share-based Compensation Arrangement by Share-based Payment Award [Line Items]43false 4rwt_ShareBasedCompensationArrangementByShareBasedPaymentAwardOtherThanOptionsExpectedVestingPeriodrwt_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse002013falsefalsefalse3falsefalsefalse00falsefalsefalsexbrli:gYearItemTypepositiveintegerShare Based Compensation Arrangement by Share Based Payment Award Other Than Options Expected Vesting PeriodNo definition available.false0Share-based compensation, vesting yearfalseEquity Compensation Plans - Additional Information (Detail) (USD $)NoRoundingNoRoundingUnKnownUnKnowntruefalsefalseSheethttp://www.redwoodtrust.com/taxonomy/role/DisclosureEquityCompensationPlansAdditionalInformation343