2.4.0.82413402 - Disclosure - Fair Value Option - Additional Information (Detail)truefalsefalse1false USDfalsefalse$D2013Q2http://www.sec.gov/CIK0000354964duration2013-04-01T00:00:002013-06-30T00:00:00usdStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$2false USDfalsefalse$D2012Q2http://www.sec.gov/CIK0000354964duration2012-04-01T00:00:002012-06-30T00:00:00usdStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$3false USDfalsefalse$D2013Q2YTDhttp://www.sec.gov/CIK0000354964duration2013-01-01T00:00:002013-06-30T00:00:00usdStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$4false USDfalsefalse$D2012Q2YTDhttp://www.sec.gov/CIK0000354964duration2012-01-01T00:00:002012-06-30T00:00:00usdStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$5false USDfalsefalse$D2012Q4YTDhttp://www.sec.gov/CIK0000354964duration2012-01-01T00:00:002012-12-31T00:00:00usdStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$1true 1hsbcfc_FairValueOptionsAbstracthsbcfc_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Fair Value, Options [Abstract]2false 2hsbcfc_FixedRateDebtAccountedForUnderFairValueOptionhsbcfc_falsecreditinstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse1000000000010000000000USD$falsetruefalse2falsefalsefalse00falsefalsefalse3truefalsefalse1000000000010000000000USD$falsetruefalse4falsefalsefalse00falsefalsefalse5truefalsefalse1020000000010200000000USD$falsetruefalsexbrli:monetaryItemTypemonetaryFixed rate debt accounted for under fair value option.No definition available.false2Fixed rate debt accounted for under fair value option3false 2us-gaap_LongTermDebtFairValueus-gaap_truecreditinstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse95000000009500000000falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse95000000009500000000falsefalsefalse4falsefalsefalse00falsefalsefalse5truefalsefalse97000000009700000000falsefalsefalsexbrli:monetaryItemTypemonetaryThe fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission.No definition available.false2Long-term debt carried at fair value4false 2hsbcfc_DueToAffiliateCarriedAtFairValuehsbcfc_falsecreditinstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse478000000478000000falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse478000000478000000falsefalsefalse4falsefalsefalse00falsefalsefalse5truefalsefalse514000000514000000falsefalsefalsexbrli:monetaryItemTypemonetaryDue to affiliate, carried at fair value.No definition available.false2Due to affiliate carried at fair value5false 2hsbcfc_FixedRateDebtNotAccountedForUnderFairValueOptionhsbcfc_falsecreditinstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse73000000007300000000falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse73000000007300000000falsefalsefalse4falsefalsefalse00falsefalsefalse5truefalsefalse81000000008100000000falsefalsefalsexbrli:monetaryItemTypemonetaryFixed rate debt not accounted for under fair value option.No definition available.false2Fair value option not elected related to fixed rate long-term debt6false 2hsbcfc_UnpaidPrincipalAmountOfFixedRateDebtAccountedForUnderFairValueOptionhsbcfc_falsecreditinstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse93000000009300000000falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse93000000009300000000falsefalsefalse4falsefalsefalse00falsefalsefalse5truefalsefalse94000000009400000000falsefalsefalsexbrli:monetaryItemTypemonetaryUnpaid principal amount of fixed rate debt accounted for under fair value option.No definition available.false2Aggregate unpaid principal balance of fixed rate debt accounted for under fair value option7false 2hsbcfc_IncreaseInDebtBalanceFromForeignCurrencyTranslationAdjustmenthsbcfc_falsecreditdurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse166000000166000000falsefalsefalse4falsefalsefalse00falsefalsefalse5truefalsefalse247000000247000000falsefalsefalsexbrli:monetaryItemTypemonetaryIncrease in debt balance from foreign currency translation adjustment.No definition available.false2Increased the debt balance8false 2hsbcfc_ForeignCurrencyTranslationGainsLossesRecordedInDerivativeRelatedIncomeExpenseAssociatedWithDebtDesignatedAtFairValuehsbcfc_falsecreditdurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse-29000000-29000000falsefalsefalse2truefalsefalse144000000144000000falsefalsefalse3truefalsefalse8100000081000000falsefalsefalse4truefalsefalse8400000084000000falsefalsefalse5falsefalsefalse00falsefalsefalsexbrli:monetaryItemTypemonetaryForeign currency translation gains losses recorded in derivative related income expense associated with debt designated at fair value.No definition available.false2Foreign Currency Translation Gains (Losses) Recorded In Derivative Related Income Expense Associated With Debt Designated At Fair Value9false 2hsbcfc_OffsettingGainsLossesRecordedInDerivativeRelatedIncomeExpenseAssociatedWithRelatedDerivativeshsbcfc_falsecreditdurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse2900000029000000falsefalsefalse2truefalsefalse-144000000-144000000falsefalsefalse3truefalsefalse-81000000-81000000falsefalsefalse4truefalsefalse-84000000-84000000falsefalsefalse5falsefalsefalse00falsefalsefalsexbrli:monetaryItemTypemonetaryOffsetting gains (losses) recorded in derivative related income (expense) associated with the related derivatives.No definition available.false2Offsetting Gains (Losses) Recorded In Derivative Related Income Expense Associated With Related Derivatives10false 2hsbcfc_CumulativeIncreasedValueOfDebtThroughFairValueOptionAdjustmentshsbcfc_falsecreditinstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse637000000637000000USD$falsetruefalse2falsefalsefalse00falsefalsefalse3truefalsefalse637000000637000000USD$falsetruefalse4falsefalsefalse00falsefalsefalse5truefalsefalse824000000824000000USD$falsetruefalsexbrli:monetaryItemTypemonetaryCumulative Increased Value of Debt through Fair Value Option AdjustmentsNo definition available.false2Cumulative increased value of debt through fair value option adjustmentsfalseFair Value Option - Additional Information (Detail) (USD $)NoRoundingUnKnownUnKnownUnKnowntruefalsefalseSheethttp://www.us.hsbc.com/role/FairValueOptionAdditionalInformationDetail510