Fair Value Measurements (Details 1) (Level 3 [Member], Income approach Valuation Technique [Member], USD $) In Millions, unless otherwise specified	9 Months Ended
	Sep. 30, 2012
International program hedging instruments [Member] | Equity options [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input [Abstract]
Assets accounted for at Fair Value on a recurring basis	$ (121)
Fair value measurements valuation techniques	Option model
Fair value measurements significant assumptions	Equity volatility
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Value Relationships of Change	Increase	[1]
Maximum [Member] | International program hedging instruments [Member] | Equity options [Member]
Fair Value Inputs [Abstract]
Fair Value Inputs Equity Volatility	27.00%
Minimum [Member] | International program hedging instruments [Member] | Equity options [Member]
Fair Value Inputs [Abstract]
Fair Value Inputs Equity Volatility	19.00%
CMBS [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input [Abstract]
Assets accounted for at Fair Value on a recurring basis	542
Fair value measurements valuation techniques	Discounted cash flows
Fair value measurements significant assumptions	Spread (encompasses prepayment, default risk and loss severity)
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Value Relationships of Change	Decrease	[2]
CMBS [Member] | Maximum [Member]
Fair Value Inputs [Abstract]
Fair Value Inputs Counterparty Credit Risk	31.36%
CMBS [Member] | Minimum [Member]
Fair Value Inputs [Abstract]
Fair Value Inputs Counterparty Credit Risk	3.00%
CMBS [Member] | Weighted Average [Member]
Fair Value Inputs [Abstract]
Fair Value Inputs Counterparty Credit Risk	10.73%	[3]
Corporate [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input [Abstract]
Assets accounted for at Fair Value on a recurring basis	354	[4]
Fair value measurements valuation techniques	Discounted cash flows	[4]
Fair value measurements significant assumptions	Spread	[4]
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Value Relationships of Change	Decrease	[2]
Corporate [Member] | Maximum [Member]
Fair Value Inputs [Abstract]
Fair Value Inputs Counterparty Credit Risk	7.90%	[4]
Corporate [Member] | Minimum [Member]
Fair Value Inputs [Abstract]
Fair Value Inputs Counterparty Credit Risk	0.90%	[4]
Corporate [Member] | Weighted Average [Member]
Fair Value Inputs [Abstract]
Fair Value Inputs Counterparty Credit Risk	3.52%	[3]
Equity Derivatives [Member] | Equity options [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input [Abstract]
Assets accounted for at Fair Value on a recurring basis	55
Fair value measurements valuation techniques	Option model
Fair value measurements significant assumptions	Equity volatility
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Value Relationships of Change	Increase	[1]
Equity Derivatives [Member] | Maximum [Member] | Equity options [Member]
Fair Value Inputs [Abstract]
Fair Value Inputs Equity Volatility	29.00%
Equity Derivatives [Member] | Minimum [Member] | Equity options [Member]
Fair Value Inputs [Abstract]
Fair Value Inputs Equity Volatility	14.00%
Interest Rate Derivative [Member] | Interest Rate Swap [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input [Abstract]
Assets accounted for at Fair Value on a recurring basis	(58)
Fair value measurements valuation techniques	Discounted cash flows
Fair value measurements significant assumptions	Swap curve  beyond 30 years
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Value Relationships of Change	Increase	[1]
Interest Rate Derivative [Member] | Maximum [Member] | Interest Rate Swap [Member]
Fair Value Inputs [Abstract]
Fair Value Inputs Interest Rate Volatility	2.60%
Interest Rate Derivative [Member] | Minimum [Member] | Interest Rate Swap [Member]
Fair Value Inputs [Abstract]
Fair Value Inputs Interest Rate Volatility	2.60%
U.S. GMWB Hedging Instruments [Member] | Equity options [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input [Abstract]
Assets accounted for at Fair Value on a recurring basis	347
Fair value measurements valuation techniques	Option model
Fair value measurements significant assumptions	Equity volatility
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Value Relationships of Change	Increase	[1]
U.S. GMWB Hedging Instruments [Member] | Customized swaps [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input [Abstract]
Assets accounted for at Fair Value on a recurring basis	269
Fair value measurements valuation techniques	Discounted cash flows
Fair value measurements significant assumptions	Equity volatility
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Value Relationships of Change	Increase	[1]
U.S. GMWB Hedging Instruments [Member] | Maximum [Member] | Equity options [Member]
Fair Value Inputs [Abstract]
Fair Value Inputs Equity Volatility	36.00%
U.S. GMWB Hedging Instruments [Member] | Maximum [Member] | Customized swaps [Member]
Fair Value Inputs [Abstract]
Fair Value Inputs Equity Volatility	50.00%
U.S. GMWB Hedging Instruments [Member] | Minimum [Member] | Equity options [Member]
Fair Value Inputs [Abstract]
Fair Value Inputs Equity Volatility	23.00%
U.S. GMWB Hedging Instruments [Member] | Minimum [Member] | Customized swaps [Member]
Fair Value Inputs [Abstract]
Fair Value Inputs Equity Volatility	10.00%
U.S. Macro Hedge Program [Member] | Equity options [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input [Abstract]
Assets accounted for at Fair Value on a recurring basis	82
Fair value measurements valuation techniques	Option model
Fair value measurements significant assumptions	Equity volatility
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Value Relationships of Change	Increase	[1]
U.S. Macro Hedge Program [Member] | Maximum [Member] | Equity options [Member]
Fair Value Inputs [Abstract]
Fair Value Inputs Equity Volatility	33.00%
U.S. Macro Hedge Program [Member] | Minimum [Member] | Equity options [Member]
Fair Value Inputs [Abstract]
Fair Value Inputs Equity Volatility	22.00%
Municipal [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input [Abstract]
Assets accounted for at Fair Value on a recurring basis	190
Fair value measurements valuation techniques	Discounted cash flows
Fair value measurements significant assumptions	Spread
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Value Relationships of Change	Decrease	[2]
Municipal [Member] | Maximum [Member]
Fair Value Inputs [Abstract]
Fair Value Inputs Treasury Yield	4.96%
Municipal [Member] | Minimum [Member]
Fair Value Inputs [Abstract]
Fair Value Inputs Treasury Yield	0.88%
Municipal [Member] | Weighted Average [Member]
Fair Value Inputs [Abstract]
Fair Value Inputs Treasury Yield	2.46%	[3]
RMBS [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input [Abstract]
Assets accounted for at Fair Value on a recurring basis	$ 1,097
Fair value measurements valuation techniques	Discounted cash flows
RMBS Type 1 [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input [Abstract]
Fair value measurements significant assumptions	Spread
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Value Relationships of Change	Decrease	[2]
RMBS Type 1 [Member] | Maximum [Member]
Fair Value Inputs [Abstract]
Fair Value Inputs Counterparty Credit Risk	19.00%
RMBS Type 1 [Member] | Minimum [Member]
Fair Value Inputs [Abstract]
Fair Value Inputs Counterparty Credit Risk	0.54%
RMBS Type 1 [Member] | Weighted Average [Member]
Fair Value Inputs [Abstract]
Fair Value Inputs Counterparty Credit Risk	6.48%	[3]
RMBS Type 2 [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input [Abstract]
Fair value measurements significant assumptions	Constant prepayment rate
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Value Relationships of Change	Decrease [4]	[2],[5]
RMBS Type 2 [Member] | Maximum [Member]
Fair Value Inputs [Abstract]
Fair Value Inputs, Prepayment Rate	12.00%
RMBS Type 2 [Member] | Minimum [Member]
Fair Value Inputs [Abstract]
Fair Value Inputs, Prepayment Rate	0.00%
RMBS Type 2 [Member] | Weighted Average [Member]
Fair Value Inputs [Abstract]
Fair Value Inputs, Prepayment Rate	2.00%	[3]
RMBS Type 3 [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input [Abstract]
Fair value measurements significant assumptions	Constant default rate
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Value Relationships of Change	Decrease	[2]
RMBS Type 3 [Member] | Maximum [Member]
Fair Value Inputs [Abstract]
Fair Value Inputs, Probability of Default	28.00%
RMBS Type 3 [Member] | Minimum [Member]
Fair Value Inputs [Abstract]
Fair Value Inputs, Probability of Default	1.00%
RMBS Type 3 [Member] | Weighted Average [Member]
Fair Value Inputs [Abstract]
Fair Value Inputs, Probability of Default	8.00%	[3]
RMBS Type 4 [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input [Abstract]
Fair value measurements significant assumptions	Loss severity
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Value Relationships of Change	Decrease	[2]
RMBS Type 4 [Member] | Maximum [Member]
Fair Value Inputs [Abstract]
Fair Value Inputs, Loss Severity	100.00%
RMBS Type 4 [Member] | Minimum [Member]
Fair Value Inputs [Abstract]
Fair Value Inputs, Loss Severity	45.00%
RMBS Type 4 [Member] | Weighted Average [Member]
Fair Value Inputs [Abstract]
Fair Value Inputs, Loss Severity	79.00%	[3]

[1] Conversely, the impact of a decrease in input would have the opposite impact to the fair value as that presented in the table. Changes are based on long positions, unless otherwise noted. Changes in fair value will be inversely impacted for short positions.

[2] Conversely, the impact of a decrease in input would have the opposite impact to the fair value as that presented in the table above.

[3] The weighted average is determined based on the fair value of the securities.

[4] Level 3 corporate securities excludes those for which the Company bases fair value on broker quotations as discussed below.

[5] Decrease for above market rate coupons and increase for below market rate coupons.