Investments (Components Of Other-Than-Temporary Impairment ("OTTI") Losses Recognized In Earnings By Asset Type) (Details) (USD $) In Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Gain (Loss) on Investments [Line Items]
Net OTTI losses recognized in earnings	$ 77	$ 44	$ 180	$ 161
Residential Mortgage-Backed [Member] | Fixed Maturity Securities [Member] | Asset-Backed Securities [Member]
Gain (Loss) on Investments [Line Items]
Net OTTI losses recognized in earnings	21	18	95	55
Commercial Mortgage-Backed [Member] | Fixed Maturity Securities [Member] | Asset-Backed Securities [Member]
Gain (Loss) on Investments [Line Items]
Net OTTI losses recognized in earnings				2
States, Municipalities And Political Subdivisions [Member] | Fixed Maturity Securities [Member]
Gain (Loss) on Investments [Line Items]
Net OTTI losses recognized in earnings				20
Corporate And Other Bonds [Member] | Fixed Maturity Securities [Member]
Gain (Loss) on Investments [Line Items]
Net OTTI losses recognized in earnings	49	17	73	59
Common Stock [Member] | Equity Securities [Member]
Gain (Loss) on Investments [Line Items]
Net OTTI losses recognized in earnings	3	5	7	10
Preferred Stock [Member] | Equity Securities [Member]
Gain (Loss) on Investments [Line Items]
Net OTTI losses recognized in earnings		4	1	13
Other Asset-Backed [Member] | Fixed Maturity Securities [Member] | Asset-Backed Securities [Member]
Gain (Loss) on Investments [Line Items]
Net OTTI losses recognized in earnings	4		4	2
Fixed Maturity Securities [Member] | Total Fixed Maturities Available-For-Sale [Member]
Gain (Loss) on Investments [Line Items]
Net OTTI losses recognized in earnings	74	35	172	138
Equity Securities [Member]
Gain (Loss) on Investments [Line Items]
Net OTTI losses recognized in earnings	$ 3	$ 9	$ 8	$ 23