Derivative Financial Instruments (Details 3) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Contractholder funds
Derivative Instruments Change in Fair Value of Fair Value Hedges
Gain (loss) on hedged risk				$ 41
Contractholder funds | Interest credited to contractholder funds
Derivative Instruments Change in Fair Value of Fair Value Hedges
Gain (loss) on hedged risk				41
Investments
Derivative Instruments Change in Fair Value of Fair Value Hedges
Gain (loss) on hedged risk	(1)	(2)	(2)	(23)
Investments | Net investment income
Derivative Instruments Change in Fair Value of Fair Value Hedges
Gain (loss) on hedged risk	(1)	(2)	(2)	(23)
Interest rate contracts
Derivative Instruments Change in Fair Value of Fair Value Hedges
Gain (loss) on derivatives	1	2	2	8
Interest rate contracts | Interest credited to contractholder funds
Derivative Instruments Change in Fair Value of Fair Value Hedges
Gain (loss) on derivatives				(7)
Interest rate contracts | Net investment income
Derivative Instruments Change in Fair Value of Fair Value Hedges
Gain (loss) on derivatives	1	2	2	23
Interest rate contracts | Realized capital gains and losses
Derivative Instruments Change in Fair Value of Fair Value Hedges
Gain (loss) on derivatives				(8)
Foreign currency and interest rate contracts
Derivative Instruments Change in Fair Value of Fair Value Hedges
Gain (loss) on derivatives				(34)
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				$ (34)