Investments (Fair Value And Gross Unrealized Losses In A Continuous Unrealized Loss Position) (Details) $ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2016 USD ($) security	Dec. 31, 2015 USD ($) security
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value
Less Than or Equal to Twelve Months	$ 2,376	$ 21,873
Greater Than Twelve Months	6,001	3,263
Continuous Unrealized Loss Position, Total	8,377	25,136
Available-for-sale Securities, Continuous Unrealized Loss Position, Gross Unrealized Losses and OTTI
Less Than or Equal to Twelve Months	89	1,411
Greater Than Twelve Months	679	724
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	$ 768	$ 2,135
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions | security	918	2,007
Equity AFS securities [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value
Less Than or Equal to Twelve Months	$ 23	$ 47
Greater Than Twelve Months	28
Continuous Unrealized Loss Position, Total	51	47
Available-for-sale Securities, Continuous Unrealized Loss Position, Gross Unrealized Losses and OTTI
Less Than or Equal to Twelve Months	3	6
Greater Than Twelve Months	2
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	5	6
Fixed maturity securities [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value
Less Than or Equal to Twelve Months	2,353	21,826
Greater Than Twelve Months	5,973	3,263
Continuous Unrealized Loss Position, Total	8,326	25,089
Available-for-sale Securities, Continuous Unrealized Loss Position, Gross Unrealized Losses and OTTI
Less Than or Equal to Twelve Months	86	1,405
Greater Than Twelve Months	677	724
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	763	2,129
Corporate bonds [Member] | Fixed maturity securities [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value
Less Than or Equal to Twelve Months	1,605	20,380
Greater Than Twelve Months	4,922	2,383
Continuous Unrealized Loss Position, Total	6,527	22,763
Available-for-sale Securities, Continuous Unrealized Loss Position, Gross Unrealized Losses and OTTI
Less Than or Equal to Twelve Months	67	1,364
Greater Than Twelve Months	548	623
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	615	1,987
ABS [Member] | Fixed maturity securities [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value
Less Than or Equal to Twelve Months	144	213
Greater Than Twelve Months	295	274
Continuous Unrealized Loss Position, Total	439	487
Available-for-sale Securities, Continuous Unrealized Loss Position, Gross Unrealized Losses and OTTI
Less Than or Equal to Twelve Months	3	4
Greater Than Twelve Months	34	29
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	37	33
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		15
Continuous Unrealized Loss Position, Total		15
Available-for-sale Securities, Continuous Unrealized Loss Position, Gross Unrealized Losses and OTTI
Less Than or Equal to Twelve Months		2
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses		2
Foreign government bonds [Member] | Fixed maturity securities [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value
Less Than or Equal to Twelve Months		37
Continuous Unrealized Loss Position, Total		37
Available-for-sale Securities, Continuous Unrealized Loss Position, Gross Unrealized Losses and OTTI
Less Than or Equal to Twelve Months		1
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses		1
RMBS [Member] | Fixed maturity securities [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value
Less Than or Equal to Twelve Months	250	627
Greater Than Twelve Months	466	371
Continuous Unrealized Loss Position, Total	716	998
Available-for-sale Securities, Continuous Unrealized Loss Position, Gross Unrealized Losses and OTTI
Less Than or Equal to Twelve Months	10	21
Greater Than Twelve Months	35	22
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	45	43
CMBS [Member] | Fixed maturity securities [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value
Less Than or Equal to Twelve Months	11	116
Greater Than Twelve Months	10	11
Continuous Unrealized Loss Position, Total	21	127
Available-for-sale Securities, Continuous Unrealized Loss Position, Gross Unrealized Losses and OTTI
Less Than or Equal to Twelve Months	1	2
Greater Than Twelve Months	1	2
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	2	4
CLOs [Member] | Fixed maturity securities [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value
Less Than or Equal to Twelve Months	283	271
Greater Than Twelve Months	63	49
Continuous Unrealized Loss Position, Total	346	320
Available-for-sale Securities, Continuous Unrealized Loss Position, Gross Unrealized Losses and OTTI
Less Than or Equal to Twelve Months	1	2
Greater Than Twelve Months		1
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	1	3
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	1	129
Greater Than Twelve Months	50	27
Continuous Unrealized Loss Position, Total	51	156
Available-for-sale Securities, Continuous Unrealized Loss Position, Gross Unrealized Losses and OTTI
Less Than or Equal to Twelve Months		8
Greater Than Twelve Months	6	4
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	6	12
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	59	38
Greater Than Twelve Months	167	148
Continuous Unrealized Loss Position, Total	226	186
Available-for-sale Securities, Continuous Unrealized Loss Position, Gross Unrealized Losses and OTTI
Less Than or Equal to Twelve Months	4	1
Greater Than Twelve Months	53	43
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	$ 57	$ 44