Derivatives (Earned Income On Derivatives) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Derivative Instruments, Gain (Loss) [Line Items]
Total earned income	$ 756	$ 721	$ 562
Derivatives Designated as Hedging Instruments [Member] | Net Investment Income
Derivative Instruments, Gain (Loss) [Line Items]
Total earned income	162	129	108
Derivatives Designated as Hedging Instruments [Member] | Interest credited to policyholder account balances
Derivative Instruments, Gain (Loss) [Line Items]
Total earned income	106	148	146
Derivatives Not Designated or Not Qualifying as Hedging Instruments [Member] | Net Investment Income
Derivative Instruments, Gain (Loss) [Line Items]
Total earned income	(4)	(6)	(6)
Derivatives Not Designated or Not Qualifying as Hedging Instruments [Member] | Net derivative gains (losses)
Derivative Instruments, Gain (Loss) [Line Items]
Total earned income	484	450	314
Derivatives Not Designated or Not Qualifying as Hedging Instruments [Member] | Policyholder Benefit And Claim [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total earned income	$ 8	$ 0	$ 0