Investments (Schedule of Details Of The Amount Of Credit Losses Of OTTI Recognized In Net Income (Loss)) (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Amortized Cost	$ 911		$ 976
Gross Unrealized Gains	32		27
Gross Unrealized Losses and OTTI	105		154
Fair Value	838		849
OTTI in Credit Losses	413	437	424	415	410	390
Corporate Bonds [Member]
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Amortized Cost	280		299
Gross Unrealized Gains	10		4
Gross Unrealized Losses and OTTI	66		98
Fair Value	224		205
OTTI in Credit Losses	112		104
RMBS [Member]
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Amortized Cost	593		636
Gross Unrealized Gains	19		22
Gross Unrealized Losses and OTTI	26		40
Fair Value	586		618
OTTI in Credit Losses	194		227
CMBS [Member]
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Amortized Cost	38		41
Gross Unrealized Gains	3		1
Gross Unrealized Losses and OTTI	13		16
Fair Value	28		26
OTTI in Credit Losses	$ 107		$ 93