Derivative Financial Instruments (Details 4) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Settlement Payments By Hedge Classification And Income Statement Location
Settlement Payments	$ 373	$ 122	$ 385	$ 193
Derivatives Designated as Hedging Instruments [Member] | Net Investment Income [Member]
Settlement Payments By Hedge Classification And Income Statement Location
Settlement Payments	31	20	55	42
Derivatives Designated as Hedging Instruments [Member] | Interest Credited to Policyholder Account Balance [Member]
Settlement Payments By Hedge Classification And Income Statement Location
Settlement Payments	38	57	83	118
Derivatives Designated as Hedging Instruments [Member] | Other Expenses [Member]
Settlement Payments By Hedge Classification And Income Statement Location
Settlement Payments	(1)	0	(2)	(1)
Derivatives Not Designated or Not Qualifying as Hedging Instruments [Member] | Net Investment Income [Member]
Settlement Payments By Hedge Classification And Income Statement Location
Settlement Payments	(2)	(3)	(3)	(4)
Derivatives Not Designated or Not Qualifying as Hedging Instruments [Member] | Other Revenues [Member]
Settlement Payments By Hedge Classification And Income Statement Location
Settlement Payments	15	18	33	33
Derivatives Not Designated or Not Qualifying as Hedging Instruments [Member] | Net Derivative Gain (Losses) [Member]
Settlement Payments By Hedge Classification And Income Statement Location
Settlement Payments	240	32	229	5
Derivatives Not Designated or Not Qualifying as Hedging Instruments [Member] | Policyholder Benefit and Claim [Member]
Settlement Payments By Hedge Classification And Income Statement Location
Settlement Payments	$ 52	$ (2)	$ (10)	$ 0