Derivative Financial Instruments (Details 4) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Settlement Payments By Hedge Classification And Income Statement Location
Settlement Payments	$ 131	$ 469	$ 516	$ 662
Derivatives Designated as Hedging Instruments [Member] | Net Investment Income [Member]
Settlement Payments By Hedge Classification And Income Statement Location
Settlement Payments	27	28	82	70
Derivatives Designated as Hedging Instruments [Member] | Interest Credited to Policyholder Account Balance [Member]
Settlement Payments By Hedge Classification And Income Statement Location
Settlement Payments	39	51	122	169
Derivatives Designated as Hedging Instruments [Member] | Other Expenses [Member]
Settlement Payments By Hedge Classification And Income Statement Location
Settlement Payments	(2)	(1)	(4)	(2)
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	(1)	(2)	(4)	(6)
Derivatives Not Designated or Not Qualifying as Hedging Instruments [Member] | Other Revenues [Member]
Settlement Payments By Hedge Classification And Income Statement Location
Settlement Payments	11	22	44	55
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	109	352	338	357
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)	$ 19	$ (62)	$ 19