Fair Value Measurements (Details 1) (USD $) In Millions	3 Months Ended	9 Months Ended
Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
States, municipalities and political subdivisions [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Financial assets, Beginning Balance	$ 84	$ 21	$ 20	$ 23
Total realized/unrealized gains (losses) included in Other comprehensive income loss	4		5	1
Purchases, sales, issuances and settlements				(3)
Purchases and issuances			53
Sales and settlements	(3)		(3)
Transfer into Level 3		0	10	17
Transfer out of Level 3	(13)		(13)	(17)
Financial assets, Ending Balance	72	21	72	21
Residential Mortgage Backed Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Financial assets, Beginning Balance	255	326	312	435
Total realized/unrealized gains (losses) included in Net income	1	4	2	6
Total realized/unrealized gains (losses) included in Other comprehensive income loss	(4)	11	(6)	22
Purchases, sales, issuances and settlements		5		11
Purchases and issuances	25		42
Sales and settlements	(9)		(29)
Transfer into Level 3	24	7	31	9
Transfer out of Level 3	(8)	(61)	(68)	(191)
Financial assets, Ending Balance	284	292	284	292
Commercial Mortgage Backed Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Financial assets, Beginning Balance	10	6	6
Total realized/unrealized gains (losses) included in Net income		(1)		(1)
Purchases, sales, issuances and settlements				6
Purchases and issuances	9		9
Transfer into Level 3	9		13
Financial assets, Ending Balance	28	5	28	5
Assets of Managed Investment Entities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Financial assets, Beginning Balance	53	46	48
Consolidate Managed Investment Entities				90
Total realized/unrealized gains (losses) included in Net income	(6)		(7)	5
Purchases, sales, issuances and settlements		(4)		(8)
Purchases and issuances	5		21
Sales and settlements	(7)		(13)
Transfer into Level 3			8	7
Transfer out of Level 3	(5)		(17)	(52)
Financial assets, Ending Balance	40	42	40	42
All other corporate [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Financial assets, Beginning Balance	382	426	436	311
Consolidate Managed Investment Entities				(6)
Total realized/unrealized gains (losses) included in Net income	2		1	(12)
Total realized/unrealized gains (losses) included in Other comprehensive income loss	11	7	17	15
Purchases, sales, issuances and settlements		14		101
Purchases and issuances	32		123
Sales and settlements	(14)		(51)
Transfer into Level 3	46	27	70	96
Transfer out of Level 3	(23)	(22)	(160)	(53)
Financial assets, Ending Balance	436	452	436	452
Equity Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Financial assets, Beginning Balance	21	24	21	25
Total realized/unrealized gains (losses) included in Other comprehensive income loss	(1)		1	(1)
Purchases and issuances	2		2
Sales and settlements			(2)
Transfer into Level 3	2		2
Transfer out of Level 3		(3)		(3)
Financial assets, Ending Balance	24	21	24	21
Trading fixed maturities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Financial assets, Beginning Balance	1	1	3	1
Purchases, sales, issuances and settlements				4
Transfer into Level 3	0	0
Transfer out of Level 3			(2)	(4)
Financial assets, Ending Balance	1	1	1	1
Liabilities of Managed Investment Entities [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Financial liabilities, Beginning Balance	(2,322)	(2,152)	(2,258)
Consolidate Managed Investment Entities				(2,100)
Total realized/unrealized Gains (losses) included in Net income	89	(51)	17	(141)
Purchases, sales, issuances and settlements		4		42
Sales and settlements	51		59
Financial liabilities, Ending Balance	(2,182)	(2,199)	(2,182)	(2,199)
Embedded derivatives [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Financial liabilities, Beginning Balance	(299)	(128)	(190)	(113)
Total realized/unrealized Gains (losses) included in Net income	31	(26)	2	(25)
Purchases, sales, issuances and settlements		(16)		(32)
Purchases and issuances	(71)		(161)
Sales and settlements	7		17
Financial liabilities, Ending Balance	$ (332)	$ (170)	$ (332)	$ (170)

Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Consolidate Managed Investment Entities.

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This element represents total gains or losses for the period (realized and unrealized), arising from assets measured at fair value on a recurring basis using unobservable inputs (Level 3), which are included in earnings or resulted in a change in net asset value.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 157

-Paragraph 32

-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.

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

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Purchases that have taken place during the period in relation to assets measured at fair value and categorized within Level 3 of the fair value hierarchy.

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-Publisher FASB

-Name Accounting Standards Codification

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-Section 50

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This element represents purchases, sales, issuances, and settlements (net) which have taken place during the period in relation to assets measured at fair value on a recurring basis using unobservable inputs (Level 3).

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Sales that have taken place during the period in relation to assets measured at fair value and categorized within Level 3 of the fair value hierarchy.

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Transfers into assets measured at fair value and categorized within Level 3 of the fair value hierarchy that have taken place during the period.

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

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Transfers out of assets measured at fair value and categorized within Level 3 of the fair value hierarchy that have taken place during the period.

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-Name Accounting Standards Codification

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This element represents an asset measured at fair value using significant unobservable inputs (Level 3) which is required for reconciliation purposes of beginning and ending balances.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 157

-Paragraph 32

-Subparagraph c

-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.

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This element represents total gains or losses for the period (realized and unrealized), arising from liabilities measured at fair value on a recurring basis using unobservable inputs (Level 3), which are included in earnings or resulted in a change in net asset value.

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Purchases that have taken place during the period in relation to liabilities measured at fair value and categorized within Level 3 of the fair value hierarchy.

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This element represents purchases, sales, issuances, and settlements (net) which have taken place during the period in relation to liabilities measured at fair value on a recurring basis using unobservable inputs (Level 3).

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Sales that have taken place during the period in relation to liabilities measured at fair value and categorized within Level 3 of the fair value hierarchy.

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Settlements that have taken place during the period in relation to liabilities measured at fair value and categorized within Level 3 of the fair value hierarchy.

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This element represents a liability measured at fair value using significant unobservable inputs (Level 3) which is required for reconciliation purposes of beginning and ending balances.

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