2.4.0.82405402 - Disclosure - Investments and Derivative Instruments (Net Investment Income (Loss)) (Details)truefalseIn Millions, unless otherwise specifiedfalse1false USDfalsefalse$D2012Q4YTDhttp://www.sec.gov/CIK0000045947duration2012-01-01T00:00:002012-12-31T00:00:00usdStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$2false USDfalsefalse$D2011Q4YTDhttp://www.sec.gov/CIK0000045947duration2011-01-01T00:00:002011-12-31T00:00:00usdStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$3false USDfalsefalse$D2010Q4YTDhttp://www.sec.gov/CIK0000045947duration2010-01-01T00:00:002010-12-31T00:00:00usdStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$1true 3us-gaap_ScheduleOfInvestmentIncomeReportedAmountsByCategoryLineItemsus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Schedule of Investment Income, Reported Amounts, by Category [Line Items]2false 4hig_SecuritiesAvailableForSaleAndOtherhig_falsecreditdurationfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1truefalsefalse25350000002535USD$falsetruefalse2truefalsefalse25720000002572USD$falsetruefalse3truefalsefalse26120000002612USD$falsetruefalsexbrli:monetaryItemTypemonetaryNet investment income earned on securities available-for-sale and other, excluding equity securities, trading.No definition available.false2Securities available-for-sale and other3false 4hig_EquitySecuritiesTradinghig_falsecreditdurationfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1truefalsefalse10000001USD$falsefalsefalse2truefalsefalse00USD$falsefalsefalse3truefalsefalse00USD$falsefalsefalsexbrli:monetaryItemTypemonetaryNet investment income earned on equity securities, trading.No definition available.false2Equity securities, trading4false 4us-gaap_NetInvestmentIncomeus-gaap_truecreditdurationfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1truefalsefalse25360000002536USD$falsefalsefalse2truefalsefalse25720000002572USD$falsefalsefalse3truefalsefalse26120000002612USD$falsefalsefalsexbrli:monetaryItemTypemonetaryThe income earned from investments in securities and property, equipment and other capital assets. It includes rent from property and equipment, dividends from shares in corporations, and interest from bonds, loans, mortgages, derivatives, commercial paper, bank accounts, certificates of deposits, treasuries, and other financial securities. It does not include realized gains and losses on investments.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 16 -Article 12 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 225 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-04.2) -URI http://asc.fasb.org/extlink&oid=6879464&loc=d3e573970-122913 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Paragraph 2 -Article 7 false2Total net investment income (loss)5false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4false USDtruefalse$D2012Q4YTD_us-gaap_ScheduleOfInvestmentIncomeReportedAmountsByCategoryAxis_us-gaap_FixedMaturitiesMemberhttp://www.sec.gov/CIK0000045947duration2012-01-01T00:00:002012-12-31T00:00:00falsefalseFixed Maturities [Member]us-gaap_ScheduleOfInvestmentIncomeReportedAmountsByCategoryAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FixedMaturitiesMemberus-gaap_ScheduleOfInvestmentIncomeReportedAmountsByCategoryAxisexplicitMemberusdStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$nanafalse0Fixed Maturities [Member]6true 3us-gaap_ScheduleOfInvestmentIncomeReportedAmountsByCategoryLineItemsus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Schedule of Investment Income, Reported Amounts, by Category [Line Items]7false 4hig_SecuritiesAvailableForSaleAndOtherhig_falsecreditdurationfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1truefalsefalse19530000001953[1]USD$falsefalsefalse2truefalsefalse19270000001927[1]USD$falsefalsefalse3truefalsefalse19670000001967[1]USD$falsefalsefalsexbrli:monetaryItemTypemonetaryNet investment income earned on securities available-for-sale and other, excluding equity securities, trading.No definition available.false2Securities available-for-sale and other8false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse7false USDtruefalse$D2012Q4YTD_us-gaap_ScheduleOfInvestmentIncomeReportedAmountsByCategoryAxis_hig_EquitySecuritiesAfsMemberhttp://www.sec.gov/CIK0000045947duration2012-01-01T00:00:002012-12-31T00:00:00falsefalseEquity Securities, AFS [Member]us-gaap_ScheduleOfInvestmentIncomeReportedAmountsByCategoryAxisxbrldihttp://xbrl.org/2006/xbrldihig_EquitySecuritiesAfsMemberus-gaap_ScheduleOfInvestmentIncomeReportedAmountsByCategoryAxisexplicitMemberusdStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$nanafalse0Equity Securities, AFS [Member]9true 3us-gaap_ScheduleOfInvestmentIncomeReportedAmountsByCategoryLineItemsus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Schedule of Investment Income, Reported Amounts, by Category [Line Items]10false 4hig_SecuritiesAvailableForSaleAndOtherhig_falsecreditdurationfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1truefalsefalse1100000011USD$falsefalsefalse2truefalsefalse1000000010USD$falsefalsefalse3truefalsefalse1400000014USD$falsefalsefalsexbrli:monetaryItemTypemonetaryNet investment income earned on securities available-for-sale and other, excluding equity securities, trading.No definition available.false2Securities available-for-sale and other11false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse10false USDtruefalse$D2012Q4YTD_us-gaap_ScheduleOfInvestmentIncomeReportedAmountsByCategoryAxis_hig_MortgageLoansMemberhttp://www.sec.gov/CIK0000045947duration2012-01-01T00:00:002012-12-31T00:00:00falsefalseMortgage Loans [Member]us-gaap_ScheduleOfInvestmentIncomeReportedAmountsByCategoryAxisxbrldihttp://xbrl.org/2006/xbrldihig_MortgageLoansMemberus-gaap_ScheduleOfInvestmentIncomeReportedAmountsByCategoryAxisexplicitMemberusdStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$nanafalse0Mortgage Loans [Member]12true 3us-gaap_ScheduleOfInvestmentIncomeReportedAmountsByCategoryLineItemsus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Schedule of Investment Income, Reported Amounts, by Category [Line Items]13false 4hig_SecuritiesAvailableForSaleAndOtherhig_falsecreditdurationfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1truefalsefalse248000000248USD$falsefalsefalse2truefalsefalse206000000206USD$falsefalsefalse3truefalsefalse199000000199USD$falsefalsefalsexbrli:monetaryItemTypemonetaryNet investment income earned on securities available-for-sale and other, excluding equity securities, trading.No definition available.false2Securities available-for-sale and other14false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse13false USDtruefalse$D2012Q4YTD_us-gaap_ScheduleOfInvestmentIncomeReportedAmountsByCategoryAxis_us-gaap_PolicyLoansMemberhttp://www.sec.gov/CIK0000045947duration2012-01-01T00:00:002012-12-31T00:00:00falsefalsePolicy Loans [Member]us-gaap_ScheduleOfInvestmentIncomeReportedAmountsByCategoryAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_PolicyLoansMemberus-gaap_ScheduleOfInvestmentIncomeReportedAmountsByCategoryAxisexplicitMemberusdStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$nanafalse0Policy Loans [Member]15true 3us-gaap_ScheduleOfInvestmentIncomeReportedAmountsByCategoryLineItemsus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Schedule of Investment Income, Reported Amounts, by Category [Line Items]16false 4hig_SecuritiesAvailableForSaleAndOtherhig_falsecreditdurationfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1truefalsefalse116000000116USD$falsefalsefalse2truefalsefalse128000000128USD$falsefalsefalse3truefalsefalse129000000129USD$falsefalsefalsexbrli:monetaryItemTypemonetaryNet investment income earned on securities available-for-sale and other, excluding equity securities, trading.No definition available.false2Securities available-for-sale and other17false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse16false USDtruefalse$D2012Q4YTD_us-gaap_ScheduleOfInvestmentIncomeReportedAmountsByCategoryAxis_hig_LimitedPartnershipsAndOtherAlternativeInvestmentsMemberhttp://www.sec.gov/CIK0000045947duration2012-01-01T00:00:002012-12-31T00:00:00falsefalseLimited Partnerships and Other Alternative Investments [Member]us-gaap_ScheduleOfInvestmentIncomeReportedAmountsByCategoryAxisxbrldihttp://xbrl.org/2006/xbrldihig_LimitedPartnershipsAndOtherAlternativeInvestmentsMemberus-gaap_ScheduleOfInvestmentIncomeReportedAmountsByCategoryAxisexplicitMemberusdStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$nanafalse0Limited Partnerships and Other Alternative Investments [Member]18true 3us-gaap_ScheduleOfInvestmentIncomeReportedAmountsByCategoryLineItemsus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Schedule of Investment Income, Reported Amounts, by Category [Line Items]19false 4hig_SecuritiesAvailableForSaleAndOtherhig_falsecreditdurationfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1truefalsefalse8500000085USD$falsefalsefalse2truefalsefalse143000000143USD$falsefalsefalse3truefalsefalse121000000121USD$falsefalsefalsexbrli:monetaryItemTypemonetaryNet investment income earned on securities available-for-sale and other, excluding equity securities, trading.No definition available.false2Securities available-for-sale and other20false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse19false USDtruefalse$D2012Q4YTD_us-gaap_ScheduleOfInvestmentIncomeReportedAmountsByCategoryAxis_us-gaap_OtherInvestmentsMemberhttp://www.sec.gov/CIK0000045947duration2012-01-01T00:00:002012-12-31T00:00:00falsefalseOther Investments [Member]us-gaap_ScheduleOfInvestmentIncomeReportedAmountsByCategoryAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_OtherInvestmentsMemberus-gaap_ScheduleOfInvestmentIncomeReportedAmountsByCategoryAxisexplicitMemberusdStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$nanafalse0Other Investments [Member]21true 3us-gaap_ScheduleOfInvestmentIncomeReportedAmountsByCategoryLineItemsus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Schedule of Investment Income, Reported Amounts, by Category [Line Items]22false 4hig_SecuritiesAvailableForSaleAndOtherhig_falsecreditdurationfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1truefalsefalse199000000199[2]USD$falsefalsefalse2truefalsefalse231000000231[2]USD$falsefalsefalse3truefalsefalse254000000254[2]USD$falsefalsefalsexbrli:monetaryItemTypemonetaryNet investment income earned on securities available-for-sale and other, excluding equity securities, trading.No definition available.false2Securities available-for-sale and other23false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse22false USDtruefalse$D2012Q4YTD_us-gaap_ScheduleOfInvestmentIncomeReportedAmountsByCategoryAxis_hig_InvestmentExpensesMemberhttp://www.sec.gov/CIK0000045947duration2012-01-01T00:00:002012-12-31T00:00:00falsefalseInvestment Expenses [Member]us-gaap_ScheduleOfInvestmentIncomeReportedAmountsByCategoryAxisxbrldihttp://xbrl.org/2006/xbrldihig_InvestmentExpensesMemberus-gaap_ScheduleOfInvestmentIncomeReportedAmountsByCategoryAxisexplicitMemberusdStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$nanafalse0Investment Expenses [Member]24true 3us-gaap_ScheduleOfInvestmentIncomeReportedAmountsByCategoryLineItemsus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Schedule of Investment Income, Reported Amounts, by Category [Line Items]25false 4hig_SecuritiesAvailableForSaleAndOtherhig_falsecreditdurationfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1truefalsefalse-77000000-77USD$falsetruefalse2truefalsefalse-73000000-73USD$falsetruefalse3truefalsefalse-72000000-72USD$falsetruefalsexbrli:monetaryItemTypemonetaryNet investment income earned on securities available-for-sale and other, excluding equity securities, trading.No definition available.false2Securities available-for-sale and other1Includes net investment income on short-term investments.2Includes income from derivatives that qualify for hedge accounting and hedge fixed maturities.falseInvestments and Derivative Instruments (Net Investment Income (Loss)) (Details) (USD $)MillionsUnKnownUnKnownUnKnowntruefalsefalseSheethttp://www.thehartford.com/role/InvestmentsAndDerivativeInstrumentsNetInvestmentIncomeLossDetails325