Investments (Schedule of Details Of The Amount Of Credit Losses Of OTTI Recognized In Net Income (Loss)) (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2013	Jun. 30, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Dec. 31, 2011
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Amortized Cost	$ 890		$ 976
Gross Unrealized Gains	38		27
Gross Unrealized Losses and OTTI	96		154
Fair Value	832		849
OTTI in Credit Losses	419	413	424	433	415	390
Corporate Bonds [Member]
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Amortized Cost	271		299
Gross Unrealized Gains	17		4
Gross Unrealized Losses and OTTI	60		98
Fair Value	228		205
OTTI in Credit Losses	122		104
RMBS [Member]
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Amortized Cost	582		636
Gross Unrealized Gains	18		22
Gross Unrealized Losses and OTTI	23		40
Fair Value	577		618
OTTI in Credit Losses	189		227
CMBS [Member]
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Amortized Cost	37		41
Gross Unrealized Gains	3		1
Gross Unrealized Losses and OTTI	13		16
Fair Value	27		26
OTTI in Credit Losses	$ 108		$ 93