Derivatives (Earned Income On Derivatives) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Derivative Instruments, Gain (Loss) [Line Items]
Total earned income	$ 794	$ 785	$ 965
Derivatives Designated as Hedging Instruments [Member] | Net investment income
Derivative Instruments, Gain (Loss) [Line Items]
Total earned income	360	299	267
Derivatives Designated as Hedging Instruments [Member] | Interest credited to policyholder account balances
Derivative Instruments, Gain (Loss) [Line Items]
Total earned income	(113)	(64)	(1)
Derivatives Designated as Hedging Instruments [Member] | Other expenses
Derivative Instruments, Gain (Loss) [Line Items]
Total earned income	(11)	(10)	(12)
Derivatives Not Designated or Not Qualifying as Hedging Instruments [Member] | Net investment income
Derivative Instruments, Gain (Loss) [Line Items]
Total earned income	0	0	(1)
Derivatives Not Designated or Not Qualifying as Hedging Instruments [Member] | Net derivative gains (losses)
Derivative Instruments, Gain (Loss) [Line Items]
Total earned income	547	551	705
Derivatives Not Designated or Not Qualifying as Hedging Instruments [Member] | Policyholder benefits and claims
Derivative Instruments, Gain (Loss) [Line Items]
Total earned income	$ 11	$ 9	$ 7