Investments (Fair Value And Gross Unrealized Losses In A Continuous Unrealized Loss Position) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014 security	Dec. 31, 2013 security
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value
Less Than or Equal to Twelve Months	$ 5,642	$ 18,322
Greater Than Twelve Months	5,320	1,839
Continuous Unrealized Loss Position, Total	10,962	20,161
Available-for-sale Securities, Continuous Unrealized Loss Position, Gross Unrealized Losses and OTTI
Less Than or Equal to Twelve Months	219	1,085
Greater Than Twelve Months	354	324
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	573	1,409
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions	1,019	1,484
Fixed maturity securities [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value
Less Than or Equal to Twelve Months	5,605	18,322
Greater Than Twelve Months	5,320	1,839
Continuous Unrealized Loss Position, Total	10,925	20,161
Available-for-sale Securities, Continuous Unrealized Loss Position, Gross Unrealized Losses and OTTI
Less Than or Equal to Twelve Months	218	1,085
Greater Than Twelve Months	354	324
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	572	1,409
Equity 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
Corporate bonds [Member] | Fixed maturity securities [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value
Less Than or Equal to Twelve Months	4,799	16,753
Greater Than Twelve Months	4,465	925
Continuous Unrealized Loss Position, Total	9,264	17,678
Available-for-sale Securities, Continuous Unrealized Loss Position, Gross Unrealized Losses and OTTI
Less Than or Equal to Twelve Months	207	1,011
Greater Than Twelve Months	244	156
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	451	1,167
Asset-backed Securities [Member] | Fixed maturity securities [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value
Less Than or Equal to Twelve Months	91	165
Greater Than Twelve Months	323	333
Continuous Unrealized Loss Position, Total	414	498
Available-for-sale Securities, Continuous Unrealized Loss Position, Gross Unrealized Losses and OTTI
Less Than or Equal to Twelve Months	2	7
Greater Than Twelve Months	41	73
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	43	80
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		163
Continuous Unrealized Loss Position, Total		163
Available-for-sale Securities, Continuous Unrealized Loss Position, Gross Unrealized Losses and OTTI
Less Than or Equal to Twelve Months		14
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses		14
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		69
Continuous Unrealized Loss Position, Total		69
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	447	488
Greater Than Twelve Months	241	267
Continuous Unrealized Loss Position, Total	688	755
Available-for-sale Securities, Continuous Unrealized Loss Position, Gross Unrealized Losses and OTTI
Less Than or Equal to Twelve Months	7	17
Greater Than Twelve Months	14	24
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	21	41
CMBS [Member] | Fixed maturity securities [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value
Less Than or Equal to Twelve Months	121	109
Greater Than Twelve Months	19	43
Continuous Unrealized Loss Position, Total	140	152
Available-for-sale Securities, Continuous Unrealized Loss Position, Gross Unrealized Losses and OTTI
Less Than or Equal to Twelve Months	1	7
Greater Than Twelve Months	10	14
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	11	21
CLOs [Member] | Fixed maturity securities [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value
Less Than or Equal to Twelve Months	110	136
Greater Than Twelve Months	70	50
Continuous Unrealized Loss Position, Total	180	186
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	5
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	2	7
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	6	377
Greater Than Twelve Months	26	24
Continuous Unrealized Loss Position, Total	32	401
Available-for-sale Securities, Continuous Unrealized Loss Position, Gross Unrealized Losses and OTTI
Less Than or Equal to Twelve Months		20
Greater Than Twelve Months	4	7
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	4	27
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	31	62
Greater Than Twelve Months	176	197
Continuous Unrealized Loss Position, Total	207	259
Available-for-sale Securities, Continuous Unrealized Loss Position, Gross Unrealized Losses and OTTI
Less Than or Equal to Twelve Months		6
Greater Than Twelve Months	40	45
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	$ 40	$ 51