Fair Value (Quantitative Information) (Details) (USD $)	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013
Interest rate contracts \| Minimum \| Income Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Swap yield	2.90%	4.01%
Interest rate contracts \| Maximum \| Income Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Swap yield	2.90%	4.50%
Foreign currency exchange rate contracts \| Minimum \| Income Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Swap yield	0.00%	5.80%
Correlation	40.00%	38.00%
Foreign currency exchange rate contracts \| Maximum \| Income Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Swap yield	0.00%	7.67%
Correlation	55.00%	47.00%
Credit contracts \| Minimum \| Income Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Credit spreads	0.98%	0.98%
Credit contracts \| Maximum \| Income Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Credit spreads	1.00%	1.01%
Equity market contracts \| Minimum \| Income Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Correlation	70.00%	0.00%
Volatility	15.00%	0.00%
Equity market contracts \| Maximum \| Income Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Correlation	70.00%	0.00%
Volatility	27.00%	0.00%
Embedded derivatives direct and ceded guaranteed minimum benefits \| Income Approach Valuation Technique \| Durations 1 - 10
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Lapse Rate, Low End	0.50%	0.50%
Lapse Rate, High End	100.00%	100.00%
Embedded derivatives direct and ceded guaranteed minimum benefits \| Income Approach Valuation Technique \| Durations 11 - 20
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Lapse Rate, Low End	3.00%	3.00%
Lapse Rate, High End	100.00%	100.00%
Embedded derivatives direct and ceded guaranteed minimum benefits \| Income Approach Valuation Technique \| Durations 21 - 116
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Lapse Rate, Low End	3.00%	3.00%
Lapse Rate, High End	100.00%	100.00%
Embedded derivatives direct and ceded guaranteed minimum benefits \| Income Approach Valuation Technique \| Ages 0 - 40
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Mortality Rate, Low End	0.00%	0.00%
Mortality Rate, High End	0.10%	0.10%
Embedded derivatives direct and ceded guaranteed minimum benefits \| Income Approach Valuation Technique \| Ages 41 - 60
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Mortality Rate, Low End	0.04%	0.04%
Mortality Rate, High End	0.65%	0.65%
Embedded derivatives direct and ceded guaranteed minimum benefits \| Income Approach Valuation Technique \| Ages 61 – 115
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Mortality Rate, Low End	0.26%	0.26%
Mortality Rate, High End	100.00%	100.00%
Embedded derivatives direct and ceded guaranteed minimum benefits \| Minimum \| Income Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Utilization rates	20.00%	20.00%
Withdrawal rates	0.07%	0.07%
Long-term equity volatilities	17.40%	17.40%
Nonperformance risk spread	0.03%	0.03%
Embedded derivatives direct and ceded guaranteed minimum benefits \| Maximum \| Income Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Utilization rates	50.00%	50.00%
Withdrawal rates	10.00%	10.00%
Long-term equity volatilities	25.00%	25.00%
Nonperformance risk spread	0.46%	0.44%
U.S. corporate and foreign corporate \| Minimum \| Market Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Delta spread adjustments	(0.40%)	(0.10%)
Matrix Pricing - Offered quotes	64	4
Offered quotes	98	33
Quoted prices	0	0
U.S. corporate and foreign corporate \| Maximum \| Market Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Delta spread adjustments	2.40%	2.40%
Matrix Pricing - Offered quotes	130	104
Offered quotes	126	140
Quoted prices	590	277
U.S. corporate and foreign corporate \| Weighted Average \| Market Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Delta spread adjustments	0.39%	0.38%
Matrix Pricing - Offered quotes	96	100
Offered quotes	101	98
Quoted prices	126	122
RMBS \| Minimum \| Market Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Offered quotes	1	69
Quoted prices	22	22
RMBS \| Maximum \| Market Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Offered quotes	118	101
Quoted prices	120	100
RMBS \| Weighted Average \| Market Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Offered quotes	93	93
Quoted prices	97	98
ABS \| Minimum \| Market Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Offered quotes	56	56
Quoted prices	15	0
ABS \| Maximum \| Market Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Offered quotes	106	106
Quoted prices	110	106
ABS \| Weighted Average \| Market Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Offered quotes	98	98
Quoted prices	100	101

Correlation.

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- Definition

Fair value inputs long-term equity volatilities.

+ References

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- Definition

Matrix Pricing - Price at which a dealer is willing to buy an instrument, used as an input to measure fair value.

+ References

No definition available.

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- Definition

Quoted prices

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No definition available.

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- Definition

Swap Yield

+ References

No definition available.

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- Definition

Fair value inputs utilization rates.

+ References

No definition available.

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- Definition

Fair value inputs withdrawal rates.

+ References

No definition available.

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- Definition

Measure of dispersion, in percentage terms (for instance, the standard deviation or variance), for a given stock price.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (e)

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- Definition

Percentage of adjustment to the observed price for a similar asset or liability when an identical transaction does not exist, used as an input to measure fair value.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (bbb)

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- Definition

Risk that one party to the contract will default expressed as a percentage, used as an input to measure fair value.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (bbb)

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- Definition

Risk associated with risk of default, credit spread risk and downgrade risk, expressed as a percentage, used as an input to measure fair value.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (bbb)

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Price at which a dealer is willing to buy an instrument, used as an input to measure fair value.

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-Publisher FASB

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-Section 50

-Paragraph 2

-Subparagraph (bbb)

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Anticipated rate of future terminations of contracts in force as of the balance sheet date at the high end of the range of reasonable estimates, which is included in determining the amount of the specified guaranteed benefit obligation as of the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 40

-Section 50

-Paragraph 6

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-Topic 944

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Anticipated rate of future terminations of contracts in force as of the balance sheet date at the low end of the range of reasonable estimates, which is included in determining the amount of the specified guaranteed benefit obligation as of the balance sheet date.

+ References

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Actuarially determined death rate of policyholders at the high end of the range of reasonable estimates, which is included in determining the amount of the specified guaranteed benefit obligation as of the balance sheet date.

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Actuarially determined death rate of policyholders at the low end of the range of reasonable estimates, which is included in determining the amount of the specified guaranteed benefit obligation as of the balance sheet date.

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