Investments (Fixed Maturities and Equity Securities Excluding Investments Classified as Trading) (Details) (USD $) In Millions	Sep. 30, 2011		Dec. 31, 2010
Summary Of Investments Other Than Investments In Related Parties Reportable Data [Line Items]
Fixed maturities, available for sale, amortized cost	$ 238,534		$ 187,754
Available For Sale Securities Equity Securities Cost	7,082		6,469
Fair Value, Fixed maturities, available for sale	252,112	[1]	194,983	[1]
Equity Securities, available for sale, at fair value (cost: 2011 $7,082; 2010 $6,469)	7,462		7,741
Fixed maturities, held to maturity, at amortized cost	5,195	[1]	5,226	[1]
Fair Value	5,484		5,477
Net unrealized gains on impaired securities relating to changes in value of securities subsequent to the impairment measurement date	232		606
Fixed Maturities [Member]
Summary Of Investments Other Than Investments In Related Parties Reportable Data [Line Items]
Fixed maturities, available for sale, amortized cost	238,534		187,754
Gross Unrealized Gains	18,832		11,497
Gross Unrealized Losses	5,254		4,268
Fair Value, Fixed maturities, available for sale	252,112		194,983
Other-than-temporary impairments in AOCI	(1,259)	[2]	(1,455)	[3]
Fixed maturities, held to maturity, at amortized cost	5,195	[4]	5,226
Gross Unrealized Gains	361		319
Gross Unrealized Losses	72		68
Fair Value	5,484	[4]	5,477
Other-than- temporary impairments in AOCI	0	[5]	0	[5]
Fixed Maturities [Member] | US Treasury And Government [Member]
Summary Of Investments Other Than Investments In Related Parties Reportable Data [Line Items]
Fixed maturities, available for sale, amortized cost	12,328		10,930
Gross Unrealized Gains	2,641		663
Gross Unrealized Losses	37		295
Fair Value, Fixed maturities, available for sale	14,932		11,298
Other-than-temporary impairments in AOCI	0		0
Fixed Maturities [Member] | Obligations of U.S. states and their political subdivisions [Member]
Summary Of Investments Other Than Investments In Related Parties Reportable Data [Line Items]
Fixed maturities, available for sale, amortized cost	2,621		2,254
Gross Unrealized Gains	378		43
Gross Unrealized Losses	18		66
Fair Value, Fixed maturities, available for sale	2,981		2,231
Other-than-temporary impairments in AOCI	0		0
Fixed Maturities [Member] | Foreign Government Debt Securities [Member]
Summary Of Investments Other Than Investments In Related Parties Reportable Data [Line Items]
Fixed maturities, available for sale, amortized cost	70,352		47,414
Gross Unrealized Gains	4,584		2,920
Gross Unrealized Losses	119		95
Fair Value, Fixed maturities, available for sale	74,817		50,239
Other-than-temporary impairments in AOCI	0		0
Fixed maturities, held to maturity, at amortized cost	1,257		1,199
Gross Unrealized Gains	122		84
Gross Unrealized Losses	0		0
Fair Value	1,379		1,283
Other-than- temporary impairments in AOCI	0	[5]	0	[5]
Fixed Maturities [Member] | Corporate Securities [Member]
Summary Of Investments Other Than Investments In Related Parties Reportable Data [Line Items]
Fixed maturities, available for sale, amortized cost	118,895		93,703
Gross Unrealized Gains	9,863		6,503
Gross Unrealized Losses	3,007		1,989
Fair Value, Fixed maturities, available for sale	125,751		98,217
Other-than-temporary impairments in AOCI	(26)		(30)
Fixed maturities, held to maturity, at amortized cost	1,122	[4]	1,059
Gross Unrealized Gains	25		12
Gross Unrealized Losses	72		67
Fair Value	1,075	[4]	1,004
Other-than- temporary impairments in AOCI	0	[5]	0	[5]
Fixed Maturities [Member] | Asset-backed Securities [Member]
Summary Of Investments Other Than Investments In Related Parties Reportable Data [Line Items]
Fixed maturities, available for sale, amortized cost	12,561	[6]	12,459	[6]
Gross Unrealized Gains	196	[6]	214	[6]
Gross Unrealized Losses	1,828	[6]	1,682	[6]
Fair Value, Fixed maturities, available for sale	10,929	[6]	10,991	[6]
Other-than-temporary impairments in AOCI	(1,226)	[6]	(1,413)	[6]
Fixed maturities, held to maturity, at amortized cost	1,250	[7]	1,179	[7]
Gross Unrealized Gains	65	[7]	48	[7]
Gross Unrealized Losses	0	[7]	1	[7]
Fair Value	1,315	[7]	1,226	[7]
Other-than- temporary impairments in AOCI	0	[5],[7]	0	[5],[7]
Fixed Maturities [Member] | Commercial Mortgage Backed Securities [Member]
Summary Of Investments Other Than Investments In Related Parties Reportable Data [Line Items]
Fixed maturities, available for sale, amortized cost	12,002		11,443
Gross Unrealized Gains	614		663
Gross Unrealized Losses	151		69
Fair Value, Fixed maturities, available for sale	12,465		12,037
Other-than-temporary impairments in AOCI	6		1
Fixed maturities, held to maturity, at amortized cost	446		475
Gross Unrealized Gains	79		106
Gross Unrealized Losses	0		0
Fair Value	525		581
Other-than- temporary impairments in AOCI	0	[5]	0	[5]
Fixed Maturities [Member] | Residential Mortgage Backed Securities [Member]
Summary Of Investments Other Than Investments In Related Parties Reportable Data [Line Items]
Fixed maturities, available for sale, amortized cost	9,775	[8]	9,551	[8]
Gross Unrealized Gains	556	[8]	491	[8]
Gross Unrealized Losses	94	[8]	72	[8]
Fair Value, Fixed maturities, available for sale	10,237	[8]	9,970	[8]
Other-than-temporary impairments in AOCI	(13)	[8]	(13)	[8]
Fixed maturities, held to maturity, at amortized cost	1,120	[8]	1,314	[8]
Gross Unrealized Gains	70	[8]	69	[8]
Gross Unrealized Losses	0	[8]	0	[8]
Fair Value	1,190	[8]	1,383	[8]
Other-than- temporary impairments in AOCI	0	[5],[8]	0	[5],[8]
Equity Securities Available For Sale [Member]
Summary Of Investments Other Than Investments In Related Parties Reportable Data [Line Items]
Available For Sale Securities Equity Securities Cost	7,082	[9]	6,469
Gross Unrealized Gains	861		1,393
Gross Unrealized Losses	481		121
Equity Securities, available for sale, at fair value (cost: 2011 $7,082; 2010 $6,469)	$ 7,462	[9]	$ 7,741

[1]          (1) See Note 5 for details of balances associated with variable interest entities.

[2] Represents the amount of other-than-temporary impairment losses in “Accumulated other comprehensive income (loss),” or “AOCI,” which were not included in earnings. Amount excludes $232 million of net unrealized gains on impaired securities relating to changes in the value of such securities subsequent to the impairment measurement date.

[3] Represents the amount of other-than-temporary impairment losses in “Accumulated other comprehensive income (loss),” or “AOCI,” which were not included in earnings. Amount excludes $606 million of net unrealized gains on impaired securities relating to changes in the value of such securities subsequent to the impairment measurement date.

[4] Excludes notes with amortized cost of $250 million (fair value, $292 million) which have been offset with the associated payables under a netting agreement.

[5] Represents the amount of other-than-temporary impairment losses in “Accumulated other comprehensive income (loss),” or “AOCI,” which were not included in earnings.

[6] Includes credit tranched securities collateralized by sub-prime mortgages, auto loans, credit cards, education loans and other asset types.

[7] Includes credit tranched securities collateralized by auto loans, credit cards, education loans, and other asset types.

[8] Includes publicly traded agency pass-through securities and collateralized mortgage obligations.

[9] As of September 30, 2011, perpetual preferred stocks of $1.3 billion were reclassified to “Other Trading Account Assets.” Prior periods were not restated.