Fair Value (Quantitative Information) (Details) (USD $)	3 Months Ended	12 Months Ended
Mar. 31, 2015	Dec. 31, 2014
Interest rate contracts \| Minimum \| Income Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Swap yield	2.56%	2.78%
Interest rate contracts \| Maximum \| Income Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Swap yield	2.71%	2.97%
Foreign currency exchange rate contracts \| Minimum \| Income Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Swap yield	(0.50%)	0.62%
Correlation	40.00%	40.00%
Foreign currency exchange rate contracts \| Maximum \| Income Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Swap yield	15.97%	24.30%
Correlation	54.00%	55.00%
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%	1.00%
Equity market contracts \| Minimum \| Income Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Correlation	70.00%	70.00%
Volatility	11.00%	15.00%
Equity market contracts \| Maximum \| Income Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Correlation	70.00%	70.00%
Volatility	28.00%	27.00%
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%	0.28%
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	0.00%	20.00%
Withdrawal rates	0.00%	0.00%
Long-term equity volatilities	8.88%	7.30%
Nonperformance risk spread	(0.15%)	(0.35%)
Embedded derivatives direct and assumed guaranteed minimum benefits \| Maximum \| Income Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Utilization rates	30.00%	50.00%
Withdrawal rates	20.00%	20.00%
Long-term equity volatilities	33.00%	33.00%
Nonperformance risk spread	1.00%	0.81%
U.S. corporate and foreign corporate securities \| Minimum \| Market Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Delta spread adjustments	(0.45%)	(0.40%)
Offered quotes	31	31
Quoted prices	6	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	780	126
Quoted prices	531	750
U.S. corporate and foreign corporate securities \| Weighted Average \| Market Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Delta spread adjustments	0.43%	0.46%
Offered quotes	242	99
Quoted prices	122	151
Foreign government \| Minimum \| Market Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Quoted prices	72	92
Foreign government \| Maximum \| Market Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Quoted prices	195	189
Foreign government \| Weighted Average \| Market Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Quoted prices	106	106
RMBS \| Minimum \| Market Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Offered quotes	30	1
Quoted prices	22	22
RMBS \| Maximum \| Market Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Offered quotes	114	118
Quoted prices	120	120
RMBS \| Weighted Average \| Market Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Offered quotes	94	93
Quoted prices	96	97
ABS \| Minimum \| Market Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Offered quotes	56	56
Quoted prices	15	15
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	99	102
Quoted prices	100	100

Correlation.

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Fair value inputs long-term equity volatilities.

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Quoted prices

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- Definition

Swap Yield

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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

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-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

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (bbb)

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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

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-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.

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 40

-Section 50

-Paragraph 6

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-Name Accounting Standards Codification

-Topic 944

-SubTopic 80

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-Paragraph 1

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-Name Accounting Standards Codification

-Topic 944

-SubTopic 20

-Section 55

-Paragraph 15

-Subparagraph (e)

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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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