2.4.0.82404409 - Disclosure - Investments (Credit Quality of Agricultural and Residential Mortgage Loans) (Details)truefalseIn Millions, unless otherwise specifiedfalse1false USDfalsefalse$I2013Q2http://www.sec.gov/CIK0000733076instant2013-06-30T00:00:000001-01-01T00:00:00numberStandardhttp://www.xbrl.org/2003/instancepurexbrli0usdStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$2false USDfalsefalse$I2012Q4http://www.sec.gov/CIK0000733076instant2012-12-31T00:00:000001-01-01T00:00:00numberStandardhttp://www.xbrl.org/2003/instancepurexbrli0usdStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$1true 4micc_AgriculturalMortgageLoansByCreditQualityIndicatorAbstractmicc_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Agricultural Mortgage Loans - by Credit Quality Indicator:2false 5us-gaap_LoansReceivableCommercialAgriculturalus-gaap_truedebitinstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse13000000001300USD$falsetruefalse2truefalsefalse12600000001260USD$falsetruefalsexbrli:monetaryItemTypemonetaryAmount before allowance of loans issued to agricultural institutions. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans covered under loss sharing agreements.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=7512638&loc=d3e5066-111524 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Statement of Position (SOP) -Number 01-6 -Paragraph 13 -Subparagraph e -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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 SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 7 -Subparagraph a -Article 9 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.7(a)(1)) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 false2Recorded investment in Mortgage Loan3false 5micc_LoansReceivableCommercialAgriculturalMortgagePercentagemicc_falsenainstantfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1truetruefalse11falsefalsefalse2truetruefalse11falsefalsefalsenum:percentItemTypepureReflects the percentage of the gross carrying amount of unpaid loans issued to agricultural businesses to provide financing on existing land or a building, which, pursuant to terms of the underlying debt instrument, are secured at a minimum but possibly exclusively by that real property to the total for all commercial agricultural mortgage loans. Mortgages represent permanent financing, and are issued to replace previously existing mortgages or pay off acquisition, development and construction loans, or to provide cash to the borrower.No definition available.false0% of Total4false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3false USDtruefalse$I2013Q2_us-gaap_FinancingReceivableInformationByCreditQualityIndicatorAxis_micc_MortgageLoansByCreditQualityIndicatorRangeOneMemberhttp://www.sec.gov/CIK0000733076instant2013-06-30T00:00:000001-01-01T00:00:00falsefalseLess than 65% [Member]us-gaap_FinancingReceivableInformationByCreditQualityIndicatorAxisxbrldihttp://xbrl.org/2006/xbrldimicc_MortgageLoansByCreditQualityIndicatorRangeOneMemberus-gaap_FinancingReceivableInformationByCreditQualityIndicatorAxisexplicitMembernumberStandardhttp://www.xbrl.org/2003/instancepurexbrli0usdStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$nanafalse0Less than 65% [Member]5true 4micc_AgriculturalMortgageLoansByCreditQualityIndicatorAbstractmicc_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Agricultural Mortgage Loans - by Credit Quality Indicator:6false 5us-gaap_LoansReceivableCommercialAgriculturalus-gaap_truedebitinstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse12100000001210USD$falsefalsefalse2truefalsefalse11840000001184USD$falsefalsefalsexbrli:monetaryItemTypemonetaryAmount before allowance of loans issued to agricultural institutions. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans covered under loss sharing agreements.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=7512638&loc=d3e5066-111524 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Statement of Position (SOP) -Number 01-6 -Paragraph 13 -Subparagraph e -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 SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 7 -Subparagraph a -Article 9 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.7(a)(1)) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 false2Recorded investment in Mortgage Loan7false 5micc_LoansReceivableCommercialAgriculturalMortgagePercentagemicc_falsenainstantfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1truetruefalse0.9310.931falsefalsefalse2truetruefalse0.9400.940falsefalsefalsenum:percentItemTypepureReflects the percentage of the gross carrying amount of unpaid loans issued to agricultural businesses to provide financing on existing land or a building, which, pursuant to terms of the underlying debt instrument, are secured at a minimum but possibly exclusively by that real property to the total for all commercial agricultural mortgage loans. Mortgages represent permanent financing, and are issued to replace previously existing mortgages or pay off acquisition, development and construction loans, or to provide cash to the borrower.No definition available.false0% of Total8false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse5false USDtruefalse$I2013Q2_us-gaap_FinancingReceivableInformationByCreditQualityIndicatorAxis_micc_MortgageLoansByCreditQualityIndicatorRangeTwoMemberhttp://www.sec.gov/CIK0000733076instant2013-06-30T00:00:000001-01-01T00:00:00falsefalse65% to 75% [Member]us-gaap_FinancingReceivableInformationByCreditQualityIndicatorAxisxbrldihttp://xbrl.org/2006/xbrldimicc_MortgageLoansByCreditQualityIndicatorRangeTwoMemberus-gaap_FinancingReceivableInformationByCreditQualityIndicatorAxisexplicitMembernumberStandardhttp://www.xbrl.org/2003/instancepurexbrli0usdStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$nanafalse065% to 75% [Member]9true 4micc_AgriculturalMortgageLoansByCreditQualityIndicatorAbstractmicc_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Agricultural Mortgage Loans - by Credit Quality Indicator:10false 5us-gaap_LoansReceivableCommercialAgriculturalus-gaap_truedebitinstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse9000000090USD$falsetruefalse2truefalsefalse7600000076USD$falsetruefalsexbrli:monetaryItemTypemonetaryAmount before allowance of loans issued to agricultural institutions. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans covered under loss sharing agreements.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=7512638&loc=d3e5066-111524 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Statement of Position (SOP) -Number 01-6 -Paragraph 13 -Subparagraph e -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 SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 7 -Subparagraph a -Article 9 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.7(a)(1)) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 false2Recorded investment in Mortgage Loan11false 5micc_LoansReceivableCommercialAgriculturalMortgagePercentagemicc_falsenainstantfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1truetruefalse0.0690.069falsefalsefalse2truetruefalse0.0600.060falsefalsefalsenum:percentItemTypepureReflects the percentage of the gross carrying amount of unpaid loans issued to agricultural businesses to provide financing on existing land or a building, which, pursuant to terms of the underlying debt instrument, are secured at a minimum but possibly exclusively by that real property to the total for all commercial agricultural mortgage loans. 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