Derivative Financial Instruments (Details 5) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Derivative Instruments, Gain (Loss) [Line Items]
Net Derivatives Gains (Losses) Recognized for Derivatives	$ (4)	$ (33)	$ (36)	$ 0
Net Derivatives Gains (Losses) Recognized for Hedged Items	3	23	25	(19)
Ineffectiveness Recognized in Net Derivatives Gains (Losses)	(1)	(10)	(11)	(19)
Interest rate swaps [Member] | Fixed maturity securities [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net Derivatives Gains (Losses) Recognized for Derivatives	(3)	(4)	(5)	(7)
Net Derivatives Gains (Losses) Recognized for Hedged Items	2	4	3	6
Ineffectiveness Recognized in Net Derivatives Gains (Losses)	(1)	0	(2)	(1)
Interest rate swaps [Member] | Policyholder account balances [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net Derivatives Gains (Losses) Recognized for Derivatives	(4)	34	(2)	34
Net Derivatives Gains (Losses) Recognized for Hedged Items	4	(35)	1	(36)
Ineffectiveness Recognized in Net Derivatives Gains (Losses)	0	(1)	(1)	(2)
Foreign currency swaps [Member] | Foreign-denominated policyholder account balances [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net Derivatives Gains (Losses) Recognized for Derivatives	3	(63)	(29)	(27)
Net Derivatives Gains (Losses) Recognized for Hedged Items	(3)	54	21	11
Ineffectiveness Recognized in Net Derivatives Gains (Losses)	$ 0	$ (9)	$ (8)	$ (16)