Fair Value (Details 1) (USD $)	9 Months Ended
	Sep. 30, 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	(1.00%)
Illiquidity premium	0.30%
Spreads from below investment grade curves	(1.79%)
Offered quotes	$ 0
Quoted prices	$ (1,411)
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	5.12%
Illiquidity premium	0.30%
Spreads from below investment grade curves	8.79%
Offered quotes	$ 600
Quoted prices	$ 826
Matrix Pricing - Offered quotes	$ 255
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	0.91%
Spreads from below investment grade curves	2.31%
Quoted prices	$ 141
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	(0.69%)
Offered quotes	$ 82
Quoted prices	$ 0
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	$ 189
Quoted prices	$ 143
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	0.64%
Quoted prices	$ 100
RMBS [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	$ 45
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	45.37%
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	4.70%
Quoted prices	$ 104
CMBS [Member] | Minimum [Member] | Market Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Spreads from below investment grade curves	0.00%
Quoted prices	$ 11
CMBS [Member] | Maximum [Member] | Market Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Spreads from below investment grade curves	90.69%
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	3.66%
Quoted prices	$ 98
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	18.30%
Offered quotes	$ 111
Quoted prices	$ 102
ABS [Member] | Weighted Average [Member] | Market Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Spreads from below investment grade curves	1.31%
Quoted prices	$ 100
Interest rate contracts [Member] | Minimum [Member] | Income Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Swap yield	2.27%
Interest rate contracts [Member] | Maximum [Member] | Income Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Swap yield	3.52%
Foreign currency contracts [Member] | Minimum [Member] | Income Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Swap yield	1.94%
Currency Correlation	41.00%
Foreign currency contracts [Member] | Maximum [Member] | Income Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Swap yield	2.31%
Currency Correlation	57.00%
Credit contracts [Member] | Minimum [Member] | Income Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Credit spreads	0.00%
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]
Volatility	13.00%
Correlation	65.00%
Equity market contracts [Member] | Maximum [Member] | Present Value techniques or option pricing model [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Volatility	34.00%
Correlation	65.00%
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	0.15%
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	1.25%
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	2.05%
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	0.13%
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%