Derivatives (Gains Losses Recognized in Income Not Designated or Qualifying) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain (Loss) on Derivative, Net	$ 501	$ (64)
Derivatives Not Designated or Not Qualifying as Hedging Instruments | Net derivative gains (losses)
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain (Loss) on Derivative, Net	2,437	751
Derivatives Not Designated or Not Qualifying as Hedging Instruments | Net derivative gains (losses) | Interest rate derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain (Loss) on Derivative, Net	1,972	552
Derivatives Not Designated or Not Qualifying as Hedging Instruments | Net derivative gains (losses) | Foreign currency exchange rate derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain (Loss) on Derivative, Net	523	669
Derivatives Not Designated or Not Qualifying as Hedging Instruments | Net derivative gains (losses) | Credit derivatives — purchased
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain (Loss) on Derivative, Net	(5)	(11)
Derivatives Not Designated or Not Qualifying as Hedging Instruments | Net derivative gains (losses) | Credit derivatives — written
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain (Loss) on Derivative, Net	(6)	3
Derivatives Not Designated or Not Qualifying as Hedging Instruments | Net derivative gains (losses) | Equity derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain (Loss) on Derivative, Net	(47)	(462)
Derivatives Not Designated or Not Qualifying as Hedging Instruments | Net investment income
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain (Loss) on Derivative, Net	(10)	(4)
Derivatives Not Designated or Not Qualifying as Hedging Instruments | Net investment income | Interest rate derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain (Loss) on Derivative, Net	0	0
Derivatives Not Designated or Not Qualifying as Hedging Instruments | Net investment income | Foreign currency exchange rate derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain (Loss) on Derivative, Net	0	0
Derivatives Not Designated or Not Qualifying as Hedging Instruments | Net investment income | Credit derivatives — purchased
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain (Loss) on Derivative, Net	10	(1)
Derivatives Not Designated or Not Qualifying as Hedging Instruments | Net investment income | Credit derivatives — written
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain (Loss) on Derivative, Net	(9)	1
Derivatives Not Designated or Not Qualifying as Hedging Instruments | Net investment income | Equity derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain (Loss) on Derivative, Net	(11)	(4)
Derivatives Not Designated or Not Qualifying as Hedging Instruments | Policyholder benefits and claims
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain (Loss) on Derivative, Net	73	(88)
Derivatives Not Designated or Not Qualifying as Hedging Instruments | Policyholder benefits and claims | Interest rate derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain (Loss) on Derivative, Net	42	11
Derivatives Not Designated or Not Qualifying as Hedging Instruments | Policyholder benefits and claims | Foreign currency exchange rate derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain (Loss) on Derivative, Net	(1)	0
Derivatives Not Designated or Not Qualifying as Hedging Instruments | Policyholder benefits and claims | Credit derivatives — purchased
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain (Loss) on Derivative, Net	0	0
Derivatives Not Designated or Not Qualifying as Hedging Instruments | Policyholder benefits and claims | Credit derivatives — written
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain (Loss) on Derivative, Net	0	0
Derivatives Not Designated or Not Qualifying as Hedging Instruments | Policyholder benefits and claims | Equity derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain (Loss) on Derivative, Net	$ 32	$ (99)