Fair Value of Financial Instruments (Fair Value Inputs Quantitative Information) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012
Indexed Annuity Contracts [Member] | Discounted Cash Flow Valuation Technique [Member]
Assets, Fair Value Disclosure [Abstract]
Assets, Fair Value Disclosure	(732)
Indexed Annuity Contracts [Member] | Maximum [Member] | Discounted Cash Flow Valuation Technique [Member]
Fair Value Inputs [Abstract]
Fair Value Inputs Lapse Rate	15.00%
Indexed Annuity Contracts [Member] | Minimum [Member] | Discounted Cash Flow Valuation Technique [Member]
Fair Value Inputs [Abstract]
Fair Value Inputs Lapse Rate	1.00%
Guaranteed Living Benefits Embedded Derivative Reserves [Member] | Monte Carlo Simulation [Member]
Liabilities, Fair Value Disclosure [Abstract]
Liabilities Fair Value Disclosure	909
Guaranteed Living Benefits Embedded Derivative Reserves [Member] | Maximum [Member] | Monte Carlo Simulation [Member]
Fair Value Inputs [Abstract]
Fair Value Inputs Lapse Rate	27.00%
Fair Value Inputs Entity Credit Risk	0.54%
Fair Value Assumptions Expected Volatility Rate	35.00%
Fair Value Inputs Utilization of Guaranteed Withdrawal	100.00%
Guaranteed Living Benefits Embedded Derivative Reserves [Member] | Minimum [Member] | Monte Carlo Simulation [Member]
Fair Value Inputs [Abstract]
Fair Value Inputs Lapse Rate	1.00%
Fair Value Inputs Entity Credit Risk	0.03%
Fair Value Assumptions Expected Volatility Rate	1.00%
Fair Value Inputs Utilization of Guaranteed Withdrawal	90.00%
Equity securities [Member] | Discounted Cash Flow Valuation Technique [Member]
Assets, Fair Value Disclosure [Abstract]
Assets, Fair Value Disclosure	25
Equity securities [Member] | Maximum [Member] | Discounted Cash Flow Valuation Technique [Member]
Assets, Fair Value Disclosure [Abstract]
Fair Value Inputs Liquidity Duration Adjustment	4.50%
Equity securities [Member] | Minimum [Member] | Discounted Cash Flow Valuation Technique [Member]
Assets, Fair Value Disclosure [Abstract]
Fair Value Inputs Liquidity Duration Adjustment	4.30%
Corporate bonds [Member] | Discounted Cash Flow Valuation Technique [Member]
Assets, Fair Value Disclosure [Abstract]
Assets, Fair Value Disclosure	922
Corporate bonds [Member] | Maximum [Member] | Discounted Cash Flow Valuation Technique [Member]
Assets, Fair Value Disclosure [Abstract]
Fair Value Inputs Liquidity Duration Adjustment	1.70%
Corporate bonds [Member] | Minimum [Member] | Discounted Cash Flow Valuation Technique [Member]
Assets, Fair Value Disclosure [Abstract]
Fair Value Inputs Liquidity Duration Adjustment	13.50%
Bonds: Foreign governments [Member] | Discounted Cash Flow Valuation Technique [Member]
Assets, Fair Value Disclosure [Abstract]
Assets, Fair Value Disclosure	46
Bonds: Foreign governments [Member] | Maximum [Member] | Discounted Cash Flow Valuation Technique [Member]
Assets, Fair Value Disclosure [Abstract]
Fair Value Inputs Liquidity Duration Adjustment	5.30%
Bonds: Foreign governments [Member] | Minimum [Member] | Discounted Cash Flow Valuation Technique [Member]
Assets, Fair Value Disclosure [Abstract]
Fair Value Inputs Liquidity Duration Adjustment	2.30%
Hybrid and redeemable preferred securities [Member] | Discounted Cash Flow Valuation Technique [Member]
Assets, Fair Value Disclosure [Abstract]
Assets, Fair Value Disclosure	21
Hybrid and redeemable preferred securities [Member] | Maximum [Member] | Discounted Cash Flow Valuation Technique [Member]
Assets, Fair Value Disclosure [Abstract]
Fair Value Inputs Liquidity Duration Adjustment	2.90%
Hybrid and redeemable preferred securities [Member] | Minimum [Member] | Discounted Cash Flow Valuation Technique [Member]
Assets, Fair Value Disclosure [Abstract]
Fair Value Inputs Liquidity Duration Adjustment	2.70%