Segment Information Level 4 (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Segment Reporting Information [Line Items]
Number of company reporting segments	6us-gaap_NumberOfReportableSegments
Segment Reporting Information, Operating Income (Loss) [Abstract]
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	$ 467us-gaap_ProfitLoss	$ 495us-gaap_ProfitLoss
Net Income (Loss) Attributable to Parent	467us-gaap_NetIncomeLoss	495us-gaap_NetIncomeLoss
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Revenues	4,617us-gaap_Revenues	4,612us-gaap_Revenues
Premiums Earned, Net	3,322us-gaap_PremiumsEarnedNet	3,302us-gaap_PremiumsEarnedNet
Insurance Commissions and Fees	459us-gaap_InsuranceCommissionsAndFees	496us-gaap_InsuranceCommissionsAndFees
earned premium, fee income and other considerations	3,781	3,798
Net Investment Income (Loss)	809us-gaap_NetInvestmentIncome	824us-gaap_NetInvestmentIncome
Realized Investment Gains (Losses)	5us-gaap_RealizedInvestmentGainsLosses	(35)us-gaap_RealizedInvestmentGainsLosses
Other Income	22us-gaap_OtherIncome	25us-gaap_OtherIncome
Workers Compensation [Member]
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Premiums Earned, Net	744	732
Property Insurance Product Line [Member]
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Premiums Earned, Net	156	136
Automobiles Commercial [Member]
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Premiums Earned, Net	148	144
Package Business [Member]
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Premiums Earned, Net	292	283
Liability [Member]
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Premiums Earned, Net	135	145
Fidelity and Surety [Member]
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Premiums Earned, Net	53	51
Professional Liability [Member]
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Premiums Earned, Net	55	50
Automobiles Consumer [Member]
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Premiums Earned, Net	655	636
Homeowners [Member]
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Premiums Earned, Net	297	292
Group Disability [Member]
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Premiums Earned, Net	371	369
Group Life and Accident [Member]
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Premiums Earned, Net	365	388
Other Group Benefit [Member]
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Premiums Earned, Net	44	42
Non Proprietary [Member]
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Fees and Commissions	149	138
Proprietary [Member]
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Fees and Commissions	30	36
Property and Casualty, Commercial Insurance Product Line [Member]
Segment Reporting Information, Operating Income (Loss) [Abstract]
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	240	242
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Premiums Earned, Net	1,583	1,541
Property and Casualty, Personal Insurance Product Line [Member]
Segment Reporting Information, Operating Income (Loss) [Abstract]
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	76	99
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Premiums Earned, Net	952	928
Affinity Earned Premiums	766	736
Property & Casualty Other Operations [Member]
Segment Reporting Information, Operating Income (Loss) [Abstract]
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	23	22
Group Insurance Policies [Member]
Segment Reporting Information, Operating Income (Loss) [Abstract]
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	52	51
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Premiums Earned, Net	780	799
Mutual Funds [Member]
Segment Reporting Information, Operating Income (Loss) [Abstract]
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	22	21
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Fees and Commissions	179	174
Talcott Resolution [Member]
Segment Reporting Information, Operating Income (Loss) [Abstract]
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	111	145
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
earned premium, fee income and other considerations	285	353
Corporate Segment [Member]
Segment Reporting Information, Operating Income (Loss) [Abstract]
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	(57)	(85)
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Insurance Commissions and Fees	$ 2	$ 3

Affinity earned premiums.

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earned premium, fee income and other considerations

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Amount of fees and commissions from financial services and banking activities and correspondent clearing. Includes fees from depositor accounts, credit cards, merchant discounts, and fiduciary and trust activities, guarantee fees, investment advisory, management, and administrative fees, transfer agent fees, and insurance commissions.

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Income from agency and brokerage operations (includes sales of annuities and supplemental contracts); service charges, commissions, and fees from the sale of insurance and related services; and management fees from separate accounts, deferred annuities, and universal life products.

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Amount, after investment expense, of income earned from investments in securities and real estate. Includes, but is not limited to, real estate investment, policy loans, dividends, and interest. Excludes realized gain (loss) on investments.

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Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements.

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Reflects the sum of all other revenue and income recognized by the entity in the period not otherwise specified in the income statement.

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Amount, after premiums ceded to other entities and premiums assumed by the entity, of premiums earned.

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Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

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