Derivatives (Earned Income On Derivatives) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Derivative Instruments, Gain (Loss) [Line Items]
Interest Income (Expense), Nonoperating, Net	$ 349	$ 321
Derivatives Designated as Hedging Instruments | Net investment income
Derivative Instruments, Gain (Loss) [Line Items]
Interest Income (Expense), Nonoperating, Net	57	58
Derivatives Designated as Hedging Instruments | Interest credited to policyholder account balances
Derivative Instruments, Gain (Loss) [Line Items]
Interest Income (Expense), Nonoperating, Net	6	2
Derivatives Designated as Hedging Instruments | Other expenses
Derivative Instruments, Gain (Loss) [Line Items]
Interest Income (Expense), Nonoperating, Net	(2)	(3)
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)
Derivatives Not Designated or Not Qualifying as Hedging Instruments | Net derivative gains (losses)
Derivative Instruments, Gain (Loss) [Line Items]
Interest Income (Expense), Nonoperating, Net	283	261
Derivatives Not Designated or Not Qualifying as Hedging Instruments | Policyholder benefits and claims
Derivative Instruments, Gain (Loss) [Line Items]
Interest Income (Expense), Nonoperating, Net	$ 5	$ 4