Fair Value (Assets And Liabilities Measured At Fair Value On A Recurring Basis) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Corporate And Other Bonds [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	$ 20,878	$ 21,036
States, Municipalities And Political Subdivisions [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	9,782	7,889
Residential Mortgage-Backed [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	5,775	6,091
Commercial Mortgage-Backed [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	1,354	993
Other Asset-Backed [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	955	763
Asset-Backed Securities [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	8,084	7,847
U.S. Treasury And Obligations Of Government-Sponsored Enterprises [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	493	137
Foreign Government [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	636	620
Redeemable Preferred Stock [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	58	54
Fixed Maturities Available For Sale [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	39,931	37,583
Fixed Maturities Trading [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	109	231
Fixed Maturities [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	40,040	37,814
Equity Securities Available For Sale [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	304	440
Equity Securities Trading [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	623	646
Equity Securities [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	927	1,086
Short Term Investments [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	5,105	7,080
Other Invested Assets [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	11	26
Receivables [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	87	76
Life Settlement Contracts [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	117	129
Separate Account Business [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	417	450
Payable To Brokers [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Liabilities, Fair Value Disclosure	(75)	(430)
Discontinued Operations Investments, Included In Other Liabilities [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Liabilities, Fair Value Disclosure		(71)
Level 1 [Member] | U.S. Treasury And Obligations Of Government-Sponsored Enterprises [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	451	76
Level 1 [Member] | Foreign Government [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	92	115
Level 1 [Member] | Redeemable Preferred Stock [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	5	3
Level 1 [Member] | Fixed Maturities Available For Sale [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	548	194
Level 1 [Member] | Fixed Maturities [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	548	194
Level 1 [Member] | Equity Securities Available For Sale [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	124	288
Level 1 [Member] | Equity Securities Trading [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	609	640
Level 1 [Member] | Equity Securities [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	733	928
Level 1 [Member] | Short Term Investments [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	4,570	6,079
Level 1 [Member] | Separate Account Business [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	21	28
Level 1 [Member] | Payable To Brokers [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Liabilities, Fair Value Disclosure	(32)	(328)
Level 1 [Member] | Discontinued Operations Investments, Included In Other Liabilities [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Liabilities, Fair Value Disclosure		(11)
Level 2 [Member] | Corporate And Other Bonds [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	20,396	20,412
Level 2 [Member] | States, Municipalities And Political Subdivisions [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	9,611	7,623
Level 2 [Member] | Residential Mortgage-Backed [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	5,323	5,324
Level 2 [Member] | Commercial Mortgage-Backed [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	1,295	920
Level 2 [Member] | Other Asset-Backed [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	612	404
Level 2 [Member] | Asset-Backed Securities [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	7,230	6,648
Level 2 [Member] | U.S. Treasury And Obligations Of Government-Sponsored Enterprises [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	42	61
Level 2 [Member] | Foreign Government [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	544	505
Level 2 [Member] | Redeemable Preferred Stock [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	53	48
Level 2 [Member] | Fixed Maturities Available For Sale [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	37,876	35,297
Level 2 [Member] | Fixed Maturities Trading [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	8	47
Level 2 [Member] | Fixed Maturities [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	37,884	35,344
Level 2 [Member] | Equity Securities Available For Sale [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	113	126
Level 2 [Member] | Equity Securities [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	113	126
Level 2 [Member] | Short Term Investments [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	508	974
Level 2 [Member] | Receivables [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	79	74
Level 2 [Member] | Separate Account Business [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	373	381
Level 2 [Member] | Payable To Brokers [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Liabilities, Fair Value Disclosure	(20)	(79)
Level 2 [Member] | Discontinued Operations Investments, Included In Other Liabilities [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Liabilities, Fair Value Disclosure		(60)
Level 3 [Member] | Corporate And Other Bonds [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	482	624
Level 3 [Member] | States, Municipalities And Political Subdivisions [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	171	266
Level 3 [Member] | Residential Mortgage-Backed [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	452	767
Level 3 [Member] | Commercial Mortgage-Backed [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	59	73
Level 3 [Member] | Other Asset-Backed [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	343	359
Level 3 [Member] | Asset-Backed Securities [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	854	1,199
Level 3 [Member] | Redeemable Preferred Stock [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis		3
Level 3 [Member] | Fixed Maturities Available For Sale [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	1,507	2,092
Level 3 [Member] | Fixed Maturities Trading [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	101	184
Level 3 [Member] | Fixed Maturities [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	1,608	2,276
Level 3 [Member] | Equity Securities Available For Sale [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	67	26
Level 3 [Member] | Equity Securities Trading [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	14	6
Level 3 [Member] | Equity Securities [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	81	32
Level 3 [Member] | Short Term Investments [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	27	27
Level 3 [Member] | Other Invested Assets [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	11	26
Level 3 [Member] | Receivables [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	8	2
Level 3 [Member] | Life Settlement Contracts [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	117	129
Level 3 [Member] | Separate Account Business [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	23	41
Level 3 [Member] | Payable To Brokers [Member]
Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Liabilities, Fair Value Disclosure	$ (23)	$ (23)