Investments (Fair Value And Gross Unrealized Losses In A Continuous Unrealized Loss Position) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2015 USD ($) security	Dec. 31, 2014 USD ($) security
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value
Less Than or Equal to Twelve Months	$ 21,873	$ 5,642
Greater Than Twelve Months	3,263	5,320
Continuous Unrealized Loss Position, Total	25,136	10,962
Available-for-sale Securities, Continuous Unrealized Loss Position, Gross Unrealized Losses and OTTI
Less Than or Equal to Twelve Months	1,411	219
Greater Than Twelve Months	724	354
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	$ 2,135	$ 573
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions | security	2,007	1,019
Available-for-sale equity securities [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value
Less Than or Equal to Twelve Months	$ 47	$ 37
Continuous Unrealized Loss Position, Total	47	37
Available-for-sale Securities, Continuous Unrealized Loss Position, Gross Unrealized Losses and OTTI
Less Than or Equal to Twelve Months	6	1
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	6	1
Fixed Maturity AFS Securities [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value
Less Than or Equal to Twelve Months	21,826	5,605
Greater Than Twelve Months	3,263	5,320
Continuous Unrealized Loss Position, Total	25,089	10,925
Available-for-sale Securities, Continuous Unrealized Loss Position, Gross Unrealized Losses and OTTI
Less Than or Equal to Twelve Months	1,405	218
Greater Than Twelve Months	724	354
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	2,129	572
Corporate bonds [Member] | Fixed Maturity AFS Securities [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value
Less Than or Equal to Twelve Months	20,380	4,799
Greater Than Twelve Months	2,383	4,465
Continuous Unrealized Loss Position, Total	22,763	9,264
Available-for-sale Securities, Continuous Unrealized Loss Position, Gross Unrealized Losses and OTTI
Less Than or Equal to Twelve Months	1,364	207
Greater Than Twelve Months	623	244
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	1,987	451
ABS [Member] | Fixed Maturity AFS Securities [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value
Less Than or Equal to Twelve Months	213	91
Greater Than Twelve Months	274	323
Continuous Unrealized Loss Position, Total	487	414
Available-for-sale Securities, Continuous Unrealized Loss Position, Gross Unrealized Losses and OTTI
Less Than or Equal to Twelve Months	4	2
Greater Than Twelve Months	29	41
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	33	43
U.S. government bonds [Member] | Fixed Maturity AFS 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 AFS 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 AFS Securities [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value
Less Than or Equal to Twelve Months	627	447
Greater Than Twelve Months	371	241
Continuous Unrealized Loss Position, Total	998	688
Available-for-sale Securities, Continuous Unrealized Loss Position, Gross Unrealized Losses and OTTI
Less Than or Equal to Twelve Months	21	7
Greater Than Twelve Months	22	14
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	43	21
CMBS [Member] | Fixed Maturity AFS Securities [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value
Less Than or Equal to Twelve Months	116	121
Greater Than Twelve Months	11	19
Continuous Unrealized Loss Position, Total	127	140
Available-for-sale Securities, Continuous Unrealized Loss Position, Gross Unrealized Losses and OTTI
Less Than or Equal to Twelve Months	2	1
Greater Than Twelve Months	2	10
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	4	11
CLOs [Member] | Fixed Maturity AFS Securities [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value
Less Than or Equal to Twelve Months	271	110
Greater Than Twelve Months	49	70
Continuous Unrealized Loss Position, Total	320	180
Available-for-sale Securities, Continuous Unrealized Loss Position, Gross Unrealized Losses and OTTI
Less Than or Equal to Twelve Months	2	1
Greater Than Twelve Months	1	1
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	3	2
State and municipal bonds [Member] | Fixed Maturity AFS Securities [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value
Less Than or Equal to Twelve Months	129	6
Greater Than Twelve Months	27	26
Continuous Unrealized Loss Position, Total	156	32
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	4	4
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	12	4
Hybrid and redeemable preferred securities [Member] | Fixed Maturity AFS Securities [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value
Less Than or Equal to Twelve Months	38	31
Greater Than Twelve Months	148	176
Continuous Unrealized Loss Position, Total	186	207
Available-for-sale Securities, Continuous Unrealized Loss Position, Gross Unrealized Losses and OTTI
Less Than or Equal to Twelve Months	1
Greater Than Twelve Months	43	40
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	$ 44	$ 40