Fair Value of Assets and Liabilities (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2011	Dec. 31, 2010	Jun. 30, 2010
Fixed income securities:
Total fixed income securities	$ 78,414	$ 79,612
Equity securities	4,954	4,811
Short-term Investments	2,536	3,279
Other investments:
Free-standing derivatives, assets	22	439	27
Separate account assets	8,175	8,676
Other assets	3	1
Total recurring basis assets	94,430	96,818
Non-recurring basis	62	120
Total assets at fair value	94,492	96,938
Assets as a percent of assets measured at fair value (as a percent)	100.00%	100.00%
Contractholder funds:
Derivatives embedded in life and annuity contracts	(629)	(653)
Other liabilities:
Free-standing derivatives, liabilities	(78)	(363)	(126)
Total liabilities at fair value	(829)	(1,016)
Liabilities as a percent of liabilities measured at fair value (as a percent)	100.00%	100.00%
U.S. government and agencies | Quoted prices in active markets for identical assets (Level 1)
Fixed income securities:
Total fixed income securities	4,298	4,976
Quoted prices in active markets for identical assets (Level 1)
Fixed income securities:
Total fixed income securities	4,298	4,976
Equity securities	4,248	4,316
Short-term Investments	271	174
Other investments:
Separate account assets	8,175	8,676
Other assets	2
Total recurring basis assets	16,994	18,142
Total assets at fair value	16,994	18,142
Assets as a percent of assets measured at fair value (as a percent)	18.00%	18.70%
Other liabilities:
Free-standing derivatives, liabilities		(2)
Total liabilities at fair value		(2)
Liabilities as a percent of liabilities measured at fair value (as a percent)		0.20%
U.S. government and agencies | Significant other observable inputs (Level 2)
Fixed income securities:
Total fixed income securities	1,889	3,620
Municipal | Significant other observable inputs (Level 2)
Fixed income securities:
Total fixed income securities	13,119	13,918
Corporate | Significant other observable inputs (Level 2)
Fixed income securities:
Total fixed income securities	40,649	35,747
Foreign government | Significant other observable inputs (Level 2)
Fixed income securities:
Total fixed income securities	3,043	3,158
Residential mortgage-backed securities ("RMBS") | Significant other observable inputs (Level 2)
Fixed income securities:
Total fixed income securities	4,796	6,199
Commercial mortgage-backed securities ("CMBS") | Significant other observable inputs (Level 2)
Fixed income securities:
Total fixed income securities	1,048	1,071
Asset-backed securities ("ABS") | Significant other observable inputs (Level 2)
Fixed income securities:
Total fixed income securities	1,975	1,827
Redeemable preferred stock | Significant other observable inputs (Level 2)
Fixed income securities:
Total fixed income securities	23	37
Significant other observable inputs (Level 2)
Fixed income securities:
Total fixed income securities	66,542	65,577
Equity securities	664	432
Short-term Investments	2,265	3,105
Other investments:
Free-standing derivatives, assets	425	651
Total recurring basis assets	69,896	69,765
Total assets at fair value	69,896	69,765
Assets as a percent of assets measured at fair value (as a percent)	74.00%	72.00%
Other liabilities:
Free-standing derivatives, liabilities	(217)	(529)
Total liabilities at fair value	(217)	(529)
Liabilities as a percent of liabilities measured at fair value (as a percent)	26.20%	52.10%
Municipal | Significant unobservable inputs (Level 3)
Fixed income securities:
Total fixed income securities	1,554	2,016
Corporate | Significant unobservable inputs (Level 3)
Fixed income securities:
Total fixed income securities	1,720	1,908
Residential mortgage-backed securities ("RMBS") | Significant unobservable inputs (Level 3)
Fixed income securities:
Total fixed income securities	1,194	1,794
Commercial mortgage-backed securities ("CMBS") | Significant unobservable inputs (Level 3)
Fixed income securities:
Total fixed income securities	938	923
Asset-backed securities ("ABS") | Significant unobservable inputs (Level 3)
Fixed income securities:
Total fixed income securities	2,167	2,417
Redeemable preferred stock | Significant unobservable inputs (Level 3)
Fixed income securities:
Total fixed income securities	1	1
Significant unobservable inputs (Level 3)
Fixed income securities:
Total fixed income securities	7,574	9,059
Equity securities	42	63
Other investments:
Free-standing derivatives, assets	22	74
Other assets	1	1
Total recurring basis assets	7,639	9,197
Non-recurring basis	62	120
Total assets at fair value	7,701	9,317
Assets as a percent of assets measured at fair value (as a percent)	8.10%	9.60%
Mortgage loans, measured on non-recurring basis	50	111
Limited partnership interests, measured on non-recurring basis	1	9
Other investments, measured on non-recurring basis	11
Contractholder funds:
Derivatives embedded in life and annuity contracts	(629)	(653)
Other liabilities:
Free-standing derivatives, liabilities	(78)	(95)
Total liabilities at fair value	(707)	(748)
Liabilities as a percent of liabilities measured at fair value (as a percent)	85.30%	73.60%
Counterparty and cash collateral netting
Other investments:
Free-standing derivatives, assets	(99)	(286)
Total recurring basis assets	(99)	(286)
Total assets at fair value	(99)	(286)
Assets as a percent of assets measured at fair value (as a percent)	(0.10%)	(0.30%)
Other liabilities:
Free-standing derivatives, liabilities	95	263
Total liabilities at fair value	95	263
Liabilities as a percent of liabilities measured at fair value (as a percent)	(11.50%)	(25.90%)
U.S. government and agencies
Fixed income securities:
Total fixed income securities	6,187	8,596
Municipal
Fixed income securities:
Total fixed income securities	14,673	15,934
Corporate
Fixed income securities:
Total fixed income securities	42,369	37,655
Foreign government
Fixed income securities:
Total fixed income securities	3,043	3,158
Residential mortgage-backed securities ("RMBS")
Fixed income securities:
Total fixed income securities	5,990	7,993
Commercial mortgage-backed securities ("CMBS")
Fixed income securities:
Total fixed income securities	1,986	1,994
Asset-backed securities ("ABS")
Fixed income securities:
Total fixed income securities	4,142	4,244
Redeemable preferred stock
Fixed income securities:
Total fixed income securities	$ 24	$ 38