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	2.78%	2.48%
Interest rate contracts \| Maximum \| Income Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Swap yield	2.97%	4.50%
Foreign currency exchange rate contracts \| Minimum \| Income Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Swap yield	0.62%	0.97%
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	24.30%	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%	60.00%
Volatility	15.00%	13.00%
Equity market contracts \| Maximum \| Income Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Correlation	70.00%	60.00%
Volatility	27.00%	28.00%
Embedded derivatives direct and assumed 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 assumed guaranteed minimum benefits \| Income Approach Valuation Technique \| Durations 11 - 20
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Lapse Rate, Low End	2.00%	2.00%
Lapse Rate, High End	100.00%	100.00%
Embedded derivatives direct and assumed guaranteed minimum benefits \| Income Approach Valuation Technique \| Durations 21 - 116
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Lapse Rate, Low End	2.00%	2.00%
Lapse Rate, High End	100.00%	100.00%
Embedded derivatives direct and assumed 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	0.28%	0.14%
Embedded derivatives direct and assumed 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	0.88%	0.88%
Embedded derivatives direct and assumed 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 assumed guaranteed minimum benefits \| Minimum \| Income Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Utilization rates	20.00%	20.00%
Withdrawal rates	0.00%	0.00%
Long-term equity volatilities	7.30%	9.14%
Nonperformance risk spread	(0.35%)	(1.08%)
Embedded derivatives direct and assumed guaranteed minimum benefits \| Maximum \| Income Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Utilization rates	50.00%	50.00%
Withdrawal rates	20.00%	40.00%
Long-term equity volatilities	33.00%	40.00%
Nonperformance risk spread	0.81%	0.83%
U.S. corporate and foreign corporate securities \| Minimum \| Market Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Delta spread adjustments	(0.40%)	(0.10%)
Offered quotes	31	33
Quoted prices	0	0
U.S. corporate and foreign corporate securities \| Maximum \| Market Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Delta spread adjustments	2.40%	2.40%
Offered quotes	126	145
Quoted prices	750	277
U.S. corporate and foreign corporate securities \| Weighted Average \| Market Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Delta spread adjustments	0.46%	0.46%
Offered quotes	99	95
Quoted prices	151	119
Foreign government \| Minimum \| Market Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Quoted prices	92	64
Foreign government \| Maximum \| Market Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Quoted prices	189	156
Foreign government \| Weighted Average \| Market Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Quoted prices	106	100
RMBS \| Minimum \| Market Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Offered quotes	1	69
Quoted prices	22	10
RMBS \| Maximum \| Market Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Offered quotes	118	101
Quoted prices	120	109
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	110
ABS \| Weighted Average \| Market Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Offered quotes	102	98
Quoted prices	100	101

Correlation.

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Fair value inputs long-term equity volatilities.

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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

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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

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

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-Paragraph 2

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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

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

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-Paragraph 2

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- Definition

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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-Topic 820

-SubTopic 10

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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.

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 40

-Section 50

-Paragraph 6

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-Topic 944

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-Topic 944

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-Paragraph 15

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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.

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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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