Fair Value (Details 1) (USD $)	12 Months Ended
	Dec. 31, 2012
U.S. corporate and foreign corporate securities [Member] | Minimum [Member] | Market Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Delta spread adjustments	(0.50%)
Illiquidity premium	0.30%
Spreads from below investment grade curves	(1.57%)
Offered quotes	$ 0
Quoted prices	$ (1,416)
Matrix Pricing - Offered quotes	$ 0
U.S. corporate and foreign corporate securities [Member] | Maximum [Member] | Market Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Delta spread adjustments	5.00%
Illiquidity premium	0.30%
Spreads from below investment grade curves	8.76%
Offered quotes	$ 555
Quoted prices	$ 830
Matrix Pricing - Offered quotes	$ 348
U.S. corporate and foreign corporate securities [Member] | Weighted Average [Member] | Market Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Delta spread adjustments	0.90%
Spreads from below investment grade curves	2.05%
Quoted prices	$ 132
Foreign government debt securities [Member] | Minimum [Member] | Market Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Spreads from below investment grade curves	(0.58%)
Offered quotes	$ 82
Quoted prices	$ 77
Foreign government debt securities [Member] | Maximum [Member] | Market Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Spreads from below investment grade curves	1.50%
Offered quotes	$ 200
Quoted prices	$ 146
Foreign government debt securities [Member] | Weighted Average [Member] | Market Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Spreads from below investment grade curves	0.72%
Quoted prices	$ 99
RMBS [Member] | Minimum [Member] | Market Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Spreads from below investment grade curves	0.09%
Offered quotes	$ 28
Quoted prices	$ 13
RMBS [Member] | Maximum [Member] | Market Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Spreads from below investment grade curves	29.80%
Offered quotes	$ 100
Quoted prices	$ 109
RMBS [Member] | Weighted Average [Member] | Market Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Spreads from below investment grade curves	5.21%
Quoted prices	$ 100
CMBS [Member] | Minimum [Member] | Market Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Spreads from below investment grade curves	0.01%
Quoted prices	$ 1
CMBS [Member] | Maximum [Member] | Market Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Spreads from below investment grade curves	91.64%
Quoted prices	$ 106
CMBS [Member] | Weighted Average [Member] | Market Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Spreads from below investment grade curves	3.74%
Quoted prices	$ 99
ABS [Member] | Minimum [Member] | Market Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Spreads from below investment grade curves	0.00%
Offered quotes	$ 0
Quoted prices	$ 40
ABS [Member] | Maximum [Member] | Market Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Spreads from below investment grade curves	18.29%
Offered quotes	$ 111
Quoted prices	$ 105
ABS [Member] | Weighted Average [Member] | Market Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Spreads from below investment grade curves	1.09%
Quoted prices	$ 100
Interest rate contracts [Member] | Minimum [Member] | Income Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Swap yield	1.86%
Interest rate contracts [Member] | Maximum [Member] | Income Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Swap yield	3.53%
Foreign currency contracts [Member] | Minimum [Member] | Income Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Swap yield	2.28%
Currency Correlation	43.00%
Foreign currency contracts [Member] | Maximum [Member] | Income Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Swap yield	7.95%
Currency Correlation	57.00%
Credit contracts [Member] | Minimum [Member] | Income Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Credit spreads	1.00%
Credit contracts [Member] | Maximum [Member] | Income Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Credit spreads	1.00%
Equity market contracts [Member] | Minimum [Member] | Present Value techniques or option pricing model [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Correlation	65.00%
Volatility	13.00%
Equity market contracts [Member] | Maximum [Member] | Present Value techniques or option pricing model [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Correlation	65.00%
Volatility	32.00%
Embedded derivatives direct and assumed guaranteed benefits [Member] | Minimum [Member] | Income Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Utilization rates	20.00%
Withdrawal rates	0.07%
Long-term equity volatilities	15.18%
Nonperformance risk spread	0.10%
Embedded derivatives direct and assumed guaranteed benefits [Member] | Minimum [Member] | Income Approach Valuation Technique [Member] | Durations 1-10 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Lapse rates	0.50%
Embedded derivatives direct and assumed guaranteed benefits [Member] | Minimum [Member] | Income Approach Valuation Technique [Member] | Durations 11-20 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Lapse rates	2.00%
Embedded derivatives direct and assumed guaranteed benefits [Member] | Minimum [Member] | Income Approach Valuation Technique [Member] | Durations 21-116 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Lapse rates	2.00%
Embedded derivatives direct and assumed guaranteed benefits [Member] | Minimum [Member] | Income Approach Valuation Technique [Member] | Ages 0-40 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Mortality rates	0.00%
Embedded derivatives direct and assumed guaranteed benefits [Member] | Minimum [Member] | Income Approach Valuation Technique [Member] | Ages 41-60 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Mortality rates	0.05%
Embedded derivatives direct and assumed guaranteed benefits [Member] | Minimum [Member] | Income Approach Valuation Technique [Member] | Ages 61-115 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Mortality rates	0.26%
Embedded derivatives direct and assumed guaranteed benefits [Member] | Maximum [Member] | Income Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Utilization rates	50.00%
Withdrawal rates	20.00%
Long-term equity volatilities	40.00%
Nonperformance risk spread	1.72%
Embedded derivatives direct and assumed guaranteed benefits [Member] | Maximum [Member] | Income Approach Valuation Technique [Member] | Durations 1-10 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Lapse rates	100.00%
Embedded derivatives direct and assumed guaranteed benefits [Member] | Maximum [Member] | Income Approach Valuation Technique [Member] | Durations 11-20 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Lapse rates	100.00%
Embedded derivatives direct and assumed guaranteed benefits [Member] | Maximum [Member] | Income Approach Valuation Technique [Member] | Durations 21-116 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Lapse rates	100.00%
Embedded derivatives direct and assumed guaranteed benefits [Member] | Maximum [Member] | Income Approach Valuation Technique [Member] | Ages 0-40 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Mortality rates	0.14%
Embedded derivatives direct and assumed guaranteed benefits [Member] | Maximum [Member] | Income Approach Valuation Technique [Member] | Ages 41-60 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Mortality rates	0.88%
Embedded derivatives direct and assumed guaranteed benefits [Member] | Maximum [Member] | Income Approach Valuation Technique [Member] | Ages 61-115 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Mortality rates	100.00%