Segment Information Level 4 (Details) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2016 USD ($)	Sep. 30, 2015 USD ($)	Sep. 30, 2016 USD ($)	Sep. 30, 2015 USD ($)
Segment Reporting Information [Line Items]
Number of company reporting segments			6
Segment Reporting Information, Operating Income (Loss) [Abstract]
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	$ 438	$ 381	$ 977	$ 1,261
Net Income (Loss) Attributable to Parent	438	381	977	1,261
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Earned premiums and fee income	3,916	3,852	11,612	11,493
Insurance Commissions and Fees	432	448	1,280	1,376
Net Investment Income (Loss)	772	730	2,203	2,335
Total Realized Investment Gains (Losses)	(17)	(44)	(119)	(30)
Other Income	24	24	67	66
Revenues	4,695	4,562	13,763	13,864
Property and Casualty, Commercial Insurance Product Line [Member]
Segment Reporting Information, Operating Income (Loss) [Abstract]
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	272	211	740	710
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Earned premiums and fee income	1,677	1,647	4,950	4,853
Property and Casualty, Personal Insurance Product Line [Member]
Segment Reporting Information, Operating Income (Loss) [Abstract]
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	29	19	(4)	136
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Earned premiums and fee income	980	977	2,931	2,895
Affinity Earned Premiums	825	797	2,400	2,300
Property & Casualty Other Operations [Member]
Segment Reporting Information, Operating Income (Loss) [Abstract]
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	31	16	(106)	(72)
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Earned premiums and fee income	0	1	0	1
Group Insurance Policies [Member]
Segment Reporting Information, Operating Income (Loss) [Abstract]
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	62	42	167	150
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Earned premiums and fee income	812	769	2,415	2,345
Mutual Funds [Member]
Segment Reporting Information, Operating Income (Loss) [Abstract]
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	21	22	61	66
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Earned premiums and fee income	178	182	517	545
Talcott Resolution [Member]
Segment Reporting Information, Operating Income (Loss) [Abstract]
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	78	74	199	402
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Earned premiums and fee income	268	275	796	848
Corporate Segment [Member]
Segment Reporting Information, Operating Income (Loss) [Abstract]
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	(55)	(3)	(80)	(131)
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Insurance Commissions and Fees	1	1	3	6
Non Proprietary [Member] \| Mutual Funds [Member]
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Earned premiums and fee income	153	154	442	457
Accident and Health Insurance Product Line [Member] \| Property and Casualty, Commercial Insurance Product Line [Member]
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Earned premiums and fee income	772	769	2,299	2,273
Accident and Health Insurance Product Line [Member] \| Group Insurance Policies [Member]
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Earned premiums and fee income	378	361	1,128	1,106
Package Business [Member] \| Property and Casualty, Commercial Insurance Product Line [Member]
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Earned premiums and fee income	313	305	925	896
Automobiles Commercial [Member] \| Property and Casualty, Commercial Insurance Product Line [Member]
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Earned premiums and fee income	162	156	472	456
Professional Liability [Member] \| Property and Casualty, Commercial Insurance Product Line [Member]
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Earned premiums and fee income	57	58	165	168
Liability [Member] \| Property and Casualty, Commercial Insurance Product Line [Member]
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Earned premiums and fee income	156	146	447	423
Surety Product Line [Member] \| Property and Casualty, Commercial Insurance Product Line [Member]
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Earned premiums and fee income	56	55	163	163
Property Insurance Product Line [Member] \| Property and Casualty, Commercial Insurance Product Line [Member]
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Earned premiums and fee income	161	158	479	474
Automobiles Consumer [Member] \| Property and Casualty, Personal Insurance Product Line [Member]
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Earned premiums and fee income	686	674	2,044	1,994
Homeowners [Member] \| Property and Casualty, Personal Insurance Product Line [Member]
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Earned premiums and fee income	294	303	887	901
Life Insurance Product Line [Member] \| Group Insurance Policies [Member]
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Earned premiums and fee income	383	365	1,134	1,106
Property & Casualty Other Operations [Member] \| Group Insurance Policies [Member]
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Earned premiums and fee income	51	43	153	133
Proprietary [Member] \| Mutual Funds [Member]
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Earned premiums and fee income	$ 25	$ 28	$ 75	$ 88

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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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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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