Derivatives (Earned Income On Derivatives) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Settlement Payments By Hedge Classification And Income Statement Location
Total earned income	$ 17	$ 12
Derivatives Designated as Hedging Instruments [Member] | Net Investment Income [Member]
Settlement Payments By Hedge Classification And Income Statement Location
Total earned income	36	24
Derivatives Designated as Hedging Instruments [Member] | Interest Credited to Policyholder Account Balance [Member]
Settlement Payments By Hedge Classification And Income Statement Location
Total earned income	35	45
Derivatives Designated as Hedging Instruments [Member] | Other Expenses [Member]
Settlement Payments By Hedge Classification And Income Statement Location
Total earned income	(3)	(1)
Derivatives Not Designated or Not Qualifying as Hedging Instruments [Member] | Net Investment Income [Member]
Settlement Payments By Hedge Classification And Income Statement Location
Total earned income	(1)	(1)
Derivatives Not Designated or Not Qualifying as Hedging Instruments [Member] | Other Revenues [Member]
Settlement Payments By Hedge Classification And Income Statement Location
Total earned income	0	18
Derivatives Not Designated or Not Qualifying as Hedging Instruments [Member] | Net Derivative Gains (Losses) [Member]
Settlement Payments By Hedge Classification And Income Statement Location
Total earned income	15	(11)
Derivatives Not Designated or Not Qualifying as Hedging Instruments [Member] | Policyholder Benefits and Claims [Member]
Settlement Payments By Hedge Classification And Income Statement Location
Total earned income	$ (65)	$ (62)