Derivatives (Earned Income On Derivatives) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Derivative Instruments, Gain (Loss) [Line Items]
Interest Income (Expense), Nonoperating, Net	$ 391	$ 318	$ 1,063	$ 941
Derivatives Designated as Hedging Instruments: | Net investment income
Derivative Instruments, Gain (Loss) [Line Items]
Interest Income (Expense), Nonoperating, Net	76	55	206	158
Derivatives Designated as Hedging Instruments: | Interest credited to policyholder account balances
Derivative Instruments, Gain (Loss) [Line Items]
Interest Income (Expense), Nonoperating, Net	0	6	7	21
Derivatives Designated as Hedging Instruments: | Other expenses
Derivative Instruments, Gain (Loss) [Line Items]
Interest Income (Expense), Nonoperating, Net	(3)	(2)	(9)	(4)
Derivatives Not Designated or Not Qualifying as Hedging Instruments: | Net investment income
Derivative Instruments, Gain (Loss) [Line Items]
Interest Income (Expense), Nonoperating, Net	0	(1)	(1)	(3)
Derivatives Not Designated or Not Qualifying as Hedging Instruments: | Net derivative gains (losses)
Derivative Instruments, Gain (Loss) [Line Items]
Interest Income (Expense), Nonoperating, Net	312	256	843	757
Derivatives Not Designated or Not Qualifying as Hedging Instruments: | Policyholder benefits and claims
Derivative Instruments, Gain (Loss) [Line Items]
Interest Income (Expense), Nonoperating, Net	$ 6	$ 4	$ 17	$ 12