2.4.0.82404415 - Disclosure - Investments (Invested Assets on Deposit, Held In Trust and Pledged as Collateral) (Details)truefalseIn Millions, unless otherwise specifiedfalse1false USDfalsefalse$I2013Q2http://www.sec.gov/CIK0000733076instant2013-06-30T00:00:000001-01-01T00:00:00usdStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$2false USDfalsefalse$I2012Q4http://www.sec.gov/CIK0000733076instant2012-12-31T00:00:000001-01-01T00:00:00usdStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$1true 1us-gaap_InvestmentsDebtAndEquitySecuritiesAbstractus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Investments, Debt and Equity Securities [Abstract]2false 2us-gaap_DepositAssetsus-gaap_truedebitinstantfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1truefalsefalse5700000057USD$falsetruefalse2truefalsefalse5800000058USD$falsetruefalsexbrli:monetaryItemTypemonetaryThe carrying amount of the asset transferred to a third party to serve as a deposit, which typically serves as security against failure by the transferor to perform under terms of an agreement.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 17 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 8 -Article 5 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.8,17) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 false2Invested assets on deposit3false 2micc_InvestedAssetsPledgedAsCollateralmicc_falsedebitinstantfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1truefalsefalse14600000001460falsefalsefalse2truefalsefalse15690000001569falsefalsefalsexbrli:monetaryItemTypemonetaryInvested assets pledged as collateral.No definition available.false2Invested assets pledged as collateral4false 2micc_AssetsOnDepositAndPledgedAsCollateralmicc_falsedebitinstantfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1truefalsefalse15170000001517USD$falsetruefalse2truefalsefalse16270000001627USD$falsetruefalsexbrli:monetaryItemTypemonetaryThe sum of the fair values, as of the date of each statement of financial position presented, of securities that are restricted as collateral for the payment of related debt obligations, primarily secured borrowings and repurchase agreements, and that are reclassified and separately reported in the statement of financial position because the transferee has the right by contract or custom to sell or re-pledge them.No definition available.false2Total invested assets on deposit and pledged as collateralfalseInvestments (Invested Assets on Deposit, Held In Trust and Pledged as Collateral) (Details) (USD $)MillionsUnKnownUnKnownUnKnowntruefalsefalseSheethttp://www.metlife.com/role/InvestmentsInvestedAssetsOnDepositHeldInTrustAndPledgedAsCollateralDetails24