2.4.0.82403403 - Disclosure - Insurance (Guarantees Related to Universal and Variable Life Contracts) (Details)truefalseIn Millions, unless otherwise specifiedfalse1false USDfalsefalseD2013Q2YTD_us-gaap_NetAmountAtRiskByProductAndGuaranteeGuaranteeTypeAxis_micc_SecondaryGuaranteesMember_us-gaap_ProductOrServiceAxis_micc_UniversalAndVariableLifeContractsMemberhttp://www.sec.gov/CIK0000733076duration2013-01-01T00:00:002013-06-30T00:00:00usdStandardhttp://www.xbrl.org/2003/iso4217USDiso42170$2false USDfalsefalseD2012Q4YTD_us-gaap_NetAmountAtRiskByProductAndGuaranteeGuaranteeTypeAxis_micc_SecondaryGuaranteesMember_us-gaap_ProductOrServiceAxis_micc_UniversalAndVariableLifeContractsMemberhttp://www.sec.gov/CIK0000733076duration2012-01-01T00:00:002012-12-31T00:00:00usdStandardhttp://www.xbrl.org/2003/iso4217USDiso42170$1false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse1false USDtruefalseD2013Q2YTD_us-gaap_NetAmountAtRiskByProductAndGuaranteeGuaranteeTypeAxis_micc_SecondaryGuaranteesMember_us-gaap_ProductOrServiceAxis_micc_UniversalAndVariableLifeContractsMemberhttp://www.sec.gov/CIK0000733076duration2013-01-01T00:00:002013-06-30T00:00:00falsefalseUniversal and Variable Life Contracts [Member]us-gaap_ProductOrServiceAxisxbrldihttp://xbrl.org/2006/xbrldimicc_UniversalAndVariableLifeContractsMemberus-gaap_ProductOrServiceAxisexplicitMemberfalsefalseSecondary Guarantees [Member]us-gaap_NetAmountAtRiskByProductAndGuaranteeGuaranteeTypeAxisxbrldihttp://xbrl.org/2006/xbrldimicc_SecondaryGuaranteesMemberus-gaap_NetAmountAtRiskByProductAndGuaranteeGuaranteeTypeAxisexplicitMemberusdStandardhttp://www.xbrl.org/2003/iso4217USDiso42170$nanafalse0Universal and Variable Life Contracts [Member] | Secondary Guarantees [Member]2true 3us-gaap_NetAmountAtRiskByProductAndGuaranteeLineItemsus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Net Amount at Risk by Product and Guarantee [Line Items]3false 4micc_NetAmountAtRiskByProductAndGuaranteeGeneralAndSeparateAccountValuemicc_falsecreditinstantfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1truefalsefalse60790000006079USD$falsetruefalse2truefalsefalse58120000005812USD$falsetruefalsexbrli:monetaryItemTypemonetaryValue of the separate and general accounts corresponding to the specified product, guarantee type and subset of the guarantee.No definition available.false2Account value (general and separate account)4false 4us-gaap_NetAmountAtRiskByProductAndGuaranteeNetAmountAtRiskInEventOfDeathus-gaap_truecreditinstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse8973300000089733USD$falsetruefalse2truefalsefalse8646800000086468USD$falsetruefalsexbrli:monetaryItemTypemonetaryThe portion of the specified guaranteed benefit amount in excess of the sum of the current account balance amounts assuming death of the insureds, corresponding to the specified guarantee or subset of the guarantee.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 20 -Section 55 -Paragraph 15 -URI http://asc.fasb.org/extlink&oid=6588021&loc=d3e7104-158389 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Statement of Position (SOP) -Number 03-1 -Section Appendix C -Paragraph 46 -Subparagraph C-1 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Statement of Position (SOP) -Number 03-1 -Paragraph 38 -Subparagraph d(2), d(3) -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 80 -Section 50 -Paragraph 1 -Subparagraph (d)(3),(5) -URI http://asc.fasb.org/extlink&oid=6484115&loc=d3e19393-158473 false2Net amount at risk5false 4us-gaap_NetAmountAtRiskByProductAndGuaranteeWeightedAverageAttainedAge1us-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse0058 yearsfalsefalsefalse2falsefalsefalse0058 yearsfalsefalsefalsexbrli:durationItemTypenaWeighted average attained age of policyholders or contract holders in the specified guarantee type and subset of guarantee class, 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 944 -SubTopic 20 -Section 55 -Paragraph 15 -URI http://asc.fasb.org/extlink&oid=6588021&loc=d3e7104-158389 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 80 -Section 50 -Paragraph 1 -Subparagraph ((d)(5)) -URI http://asc.fasb.org/extlink&oid=6484115&loc=d3e19393-158473 false0Average attained age of policyholdersfalseInsurance (Guarantees Related to Universal and Variable Life Contracts) (Details) (Universal and Variable Life Contracts [Member], Secondary Guarantees [Member], USD $)MillionsUnKnownUnKnownUnKnowntruefalsefalseSheethttp://www.metlife.com/role/InsuranceGuaranteesRelatedToUniversalAndVariableLifeContractsDetails25