Derivative Financial Instruments (Details 3) (USD $) In Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Interest rate contracts
Derivative Instruments Change in Fair Value of Fair Value Hedges
Gain (loss) on derivatives	$ (1)	$ (24)	$ 9	$ (70)
Interest rate contracts | Net investment income.
Derivative Instruments Change in Fair Value of Fair Value Hedges
Gain (loss) on derivatives	(1)	(32)	24	(88)
Interest rate contracts | Realized capital gains and losses
Derivative Instruments Change in Fair Value of Fair Value Hedges
Gain (loss) on derivatives		2	(8)	4
Interest rate contracts | Interest credited to contractholder funds
Derivative Instruments Change in Fair Value of Fair Value Hedges
Gain (loss) on derivatives		6	(7)	14
Foreign currency and interest rate contracts
Derivative Instruments Change in Fair Value of Fair Value Hedges
Gain (loss) on derivatives		18	(34)	(40)
Foreign currency and interest rate contracts | Realized capital gains and losses
Derivative Instruments Change in Fair Value of Fair Value Hedges
Gain (loss) on derivatives				(1)
Foreign currency and interest rate contracts | Interest credited to contractholder funds
Derivative Instruments Change in Fair Value of Fair Value Hedges
Gain (loss) on derivatives		18	(34)	(39)
Contractholder funds
Derivative Instruments Change in Fair Value of Fair Value Hedges
Gain (loss) on hedged risk		(24)	41	25
Contractholder funds | Interest credited to contractholder funds
Derivative Instruments Change in Fair Value of Fair Value Hedges
Gain (loss) on hedged risk		(24)	41	25
Investments;
Derivative Instruments Change in Fair Value of Fair Value Hedges
Gain (loss) on hedged risk	(1)	32	(24)	88
Investments; | Net investment income.
Derivative Instruments Change in Fair Value of Fair Value Hedges
Gain (loss) on hedged risk	$ (1)	$ 32	$ (24)	$ 88