Derivative Financial Instruments (Details 3) (USD $) In Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Interest rate contracts
Derivative Instruments Change in Fair Value of Fair Value Hedges
Gain (loss) on derivatives	$ 2	$ (32)	$ 8	$ (46)
Interest rate contracts | Net investment income.
Derivative Instruments Change in Fair Value of Fair Value Hedges
Gain (loss) on derivatives	2	(43)	23	(56)
Interest rate contracts | Realized capital gains and losses
Derivative Instruments Change in Fair Value of Fair Value Hedges
Gain (loss) on derivatives		2	(8)	2
Interest rate contracts | Interest credited to contractholder funds
Derivative Instruments Change in Fair Value of Fair Value Hedges
Gain (loss) on derivatives		9	(7)	8
Foreign currency and interest rate contracts
Derivative Instruments Change in Fair Value of Fair Value Hedges
Gain (loss) on derivatives		(25)	(34)	(58)
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)		(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		(24)	(34)	(57)
Interest credited to contractholder funds | Contractholder funds
Derivative Instruments Change in Fair Value of Fair Value Hedges
Gain (loss) on hedged risk		15	41	49
Contractholder funds
Derivative Instruments Change in Fair Value of Fair Value Hedges
Gain (loss) on hedged risk		15	41	49
Net investment income. | Investments;
Derivative Instruments Change in Fair Value of Fair Value Hedges
Gain (loss) on hedged risk	(2)	43	(23)	56
Investments;
Derivative Instruments Change in Fair Value of Fair Value Hedges
Gain (loss) on hedged risk	$ (2)	$ 43	$ (23)	$ 56