2.4.0.82404413 - Disclosure - Investments (Changes in Net Unrealized Investment Gains Losses) (Details)truefalseIn Millions, unless otherwise specifiedfalse1false USDfalsefalse$D2013Q2YTDhttp://www.sec.gov/CIK0000733076duration2013-01-01T00:00:002013-06-30T00:00:00usdStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$1true 2us-gaap_OtherComprehensiveIncomeLossBeforeTaxPortionAttributableToParentAbstractus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Changes In Net Unrealized Investment Gains Losses Included In Accumulated Other Comprehensive Loss [Abstract]2false 3micc_NetUnrealizedInvestmentGainsLossesIncludedInAccumulatedOtherComprehensiveIncomeLossAttributableToCompanymicc_falsecreditinstantfalsefalsefalsefalsefalsetruefalsefalseperiodStartLabel1truefalsefalse24490000002449USD$falsetruefalsexbrli:monetaryItemTypemonetaryThis item presents net unrealized investment gains (losses) attributable to the Company.No definition available.false2Balance, beginning of period3false 3micc_ChangesInNetUnrealizedInvestmentGainsLossesRelatedToDebtSecuritiesOnWhichNoncreditOttiLossesHaveBeenRecognizedmicc_falsecreditdurationfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1truefalsefalse1200000012falsefalsefalsexbrli:monetaryItemTypemonetaryThis item presents the increase (decrease) in net unrealized investment gains (losses) on fixed maturity securities on which noncredit OTTI losses have been recognized.No definition available.false2Fixed maturity securities on which noncredit OTTI losses have been recognized4false 3micc_ChangesInNetUnrealizedInvestmentGainsLossesRelatedToUnrealizedInvestmentGainsLossesDuringPeriodmicc_falsecreditdurationfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1truefalsefalse-2519000000-2519falsefalsefalsexbrli:monetaryItemTypemonetaryThis item presents the increase (decrease) in net unrealized investment gains (losses) related to unrealized investment gains (losses) during the period.No definition available.false2Unrealized investment gains (losses) during the year5true 3us-gaap_AvailableForSaleSecuritiesGrossUnrealizedGainLossAbstractus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Unrealized investment gains (losses) relating to [Abstract]6false 4micc_ChangesInNetUnrealizedInvestmentGainsLossesRelatedToInsuranceLiabilityGainLossRecognitionmicc_falsecreditdurationfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1truefalsefalse537000000537falsefalsefalsexbrli:monetaryItemTypemonetaryThis item presents the increase (decrease) in net unrealized investment gains (losses) related to insurance liability gain (loss) recognition.No definition available.false2Insurance liability gain (loss) recognition7false 4micc_ChangesInNetUnrealizedInvestmentGainsLossesRelatedToDacAndVobaRelatedToNonCreditOttiLossesRecognizedInOtherComprehensiveIncomeLossmicc_falsecreditdurationfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1truefalsefalse-3000000-3falsefalsefalsexbrli:monetaryItemTypemonetaryChanges in net unrealized investment gains (losses) related to DAC and VOBA related noncredit OTTI losses recognized in other comprehensive income (loss).No definition available.false2DAC and VOBA related to noncredit OTTI losses recognized in accumulated other comprehensive income (loss)8false 4micc_ChangesInNetUnrealizedInvestmentGainsLossesRelatedToDacAndVobamicc_falsecreditdurationfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1truefalsefalse311000000311falsefalsefalsexbrli:monetaryItemTypemonetaryThis item presents the increase (decrease) in net unrealized investment gains (losses) related to DAC and VOBA.No definition available.false2DAC and VOBA9false 4micc_ChangesInNetUnrealizedInvestmentGainsLossesRelatedToDeferredIncomeTaxBenefitExpenseRelatedToNonCreditOttiLossesRecognizedInOtherComprehensiveIncomeLossmicc_falsecreditdurationfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1truefalsefalse-3000000-3falsefalsefalsexbrli:monetaryItemTypemonetaryChanges in net unrealized investment gains (losses) related to deferred income tax benefit (expense) related to noncredit OTTI losses recognized in other comprehensive income (loss).No definition available.false2Deferred income tax benefit (expense) related to noncredit OTTI losses recognized in accumulated other comprehensive income (loss)10false 4micc_IncomeTaxExpenseOnChangeInUnrealizedGainOrLossmicc_falsedebitdurationfalsefalsefalsefalsefalsefalsefalsetruenegatedLabel1truefalsefalse596000000596falsefalsefalsexbrli:monetaryItemTypemonetaryThis item represents the tax effects occurring during the period which are related to the net unrealized gain (loss) resulting from changes in the fair [carrying] value during the period of available-for-sale securities and from changes in certain insurance related assets and liabilities. Such tax affects would have been charged or credited directly to other comprehensive income or to related components of shareholders' equity.No definition available.false2Deferred income tax benefit (expense)11false 3micc_NetUnrealizedInvestmentGainsLossesIncludedInAccumulatedOtherComprehensiveIncomeLossAttributableToCompanymicc_falsecreditinstantfalsefalsefalsefalsefalsefalsetruefalseperiodEndLabel1truefalsefalse13800000001380falsefalsefalsexbrli:monetaryItemTypemonetaryThis item presents net unrealized investment gains (losses) attributable to the Company.No definition available.false2Balance,end of period12false 3micc_ChangesInNetUnrealizedInvestmentGainsLossesExcludingPortionAttributableToNoncontrollingInterestsmicc_falsecreditdurationfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1truefalsefalse-1069000000-1069USD$falsetruefalsexbrli:monetaryItemTypemonetaryThis item presents the increase (decrease) in net unrealized investment gains (losses) excluding portion attributable to noncontrolling interests.No definition available.false2Changes in net unrealized investment gains (losses)falseInvestments (Changes in Net Unrealized Investment Gains Losses) (Details) (USD $)MillionsUnKnownUnKnownUnKnowntruefalsefalseSheethttp://www.metlife.com/role/InvestmentsChangesInNetUnrealizedInvestmentGainsLossesDetails112