Investments (Fair Value And Gross Unrealized Losses In A Continuous Unrealized Loss Position) (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2013 security	Dec. 31, 2012 security
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value
Less Than or Equal to Twelve Months	$ 16,209	$ 3,343
Greater Than Twelve Months	1,279	1,616
Continuous Unrealized Loss Position, Total	17,488	4,959
Available-for-sale Securities, Continuous Unrealized Loss Position, Gross Unrealized Losses and OTTI
Less Than or Equal to Twelve Months	944	214
Greater Than Twelve Months	251	301
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	1,195	515
Available For Sale Securities In Unrealized Loss Position Qualitative Disclosure Number Of Positions	1,331	626
Fixed Maturity Securities [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value
Less Than or Equal to Twelve Months	16,180	3,336
Greater Than Twelve Months	1,279	1,616
Continuous Unrealized Loss Position, Total	17,459	4,952
Available-for-sale Securities, Continuous Unrealized Loss Position, Gross Unrealized Losses and OTTI
Less Than or Equal to Twelve Months	943	212
Greater Than Twelve Months	251	301
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	1,194	513
Equity AFS Securities [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value
Less Than or Equal to Twelve Months	29	7
Continuous Unrealized Loss Position, Total	29	7
Available-for-sale Securities, Continuous Unrealized Loss Position, Gross Unrealized Losses and OTTI
Less Than or Equal to Twelve Months	1	2
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	1	2
Corporate Bonds [Member] | Fixed Maturity Securities [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value
Less Than or Equal to Twelve Months	14,856	2,853
Greater Than Twelve Months	786	934
Continuous Unrealized Loss Position, Total	15,642	3,787
Available-for-sale Securities, Continuous Unrealized Loss Position, Gross Unrealized Losses and OTTI
Less Than or Equal to Twelve Months	858	145
Greater Than Twelve Months	162	182
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	1,020	327
U.S. Government Bonds [Member] | Fixed Maturity Securities [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value
Less Than or Equal to Twelve Months	149
Continuous Unrealized Loss Position, Total	149
Available-for-sale Securities, Continuous Unrealized Loss Position, Gross Unrealized Losses and OTTI
Less Than or Equal to Twelve Months	6
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	6
RMBS [Member] | Fixed Maturity Securities [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value
Less Than or Equal to Twelve Months	653	272
Greater Than Twelve Months	139	199
Continuous Unrealized Loss Position, Total	792	471
Available-for-sale Securities, Continuous Unrealized Loss Position, Gross Unrealized Losses and OTTI
Less Than or Equal to Twelve Months	35	39
Greater Than Twelve Months	15	24
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	50	63
CMBS [Member] | Fixed Maturity Securities [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value
Less Than or Equal to Twelve Months	141	66
Greater Than Twelve Months	56	113
Continuous Unrealized Loss Position, Total	197	179
Available-for-sale Securities, Continuous Unrealized Loss Position, Gross Unrealized Losses and OTTI
Less Than or Equal to Twelve Months	18	16
Greater Than Twelve Months	2	19
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	20	35
CDOs [Member] | Fixed Maturity Securities [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value
Less Than or Equal to Twelve Months	53	10
Greater Than Twelve Months	48	53
Continuous Unrealized Loss Position, Total	101	63
Available-for-sale Securities, Continuous Unrealized Loss Position, Gross Unrealized Losses and OTTI
Less Than or Equal to Twelve Months	8	8
Greater Than Twelve Months	1	3
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	9	11
State And Municipal Bonds [Member] | Fixed Maturity Securities [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value
Less Than or Equal to Twelve Months	229	64
Greater Than Twelve Months	24	24
Continuous Unrealized Loss Position, Total	253	88
Available-for-sale Securities, Continuous Unrealized Loss Position, Gross Unrealized Losses and OTTI
Less Than or Equal to Twelve Months	12	1
Greater Than Twelve Months	4	6
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	16	7
Hybrid And Redeemable Preferred Securities [Member] | Fixed Maturity Securities [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value
Less Than or Equal to Twelve Months	99	71
Greater Than Twelve Months	226	293
Continuous Unrealized Loss Position, Total	325	364
Available-for-sale Securities, Continuous Unrealized Loss Position, Gross Unrealized Losses and OTTI
Less Than or Equal to Twelve Months	6	3
Greater Than Twelve Months	67	67
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	$ 73	$ 70