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%
Credit contracts \| Minimum \| Income Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Credit spreads	0.99%	0.99%
Credit contracts \| Maximum \| Income Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Credit spreads	0.99%	0.99%
Equity market contracts \| Minimum \| Income Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Volatility	15.00%	15.00%
Correlation	70.00%	70.00%
Equity market contracts \| Maximum \| Income Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Volatility	28.00%	27.00%
Correlation	70.00%	70.00%
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	0.09%	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	0.00%	20.00%
Withdrawal rates	0.08%	0.07%
Long-term equity volatilities	17.40%	17.40%
Nonperformance risk spread	0.04%	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	30.00%	50.00%
Withdrawal rates	10.00%	10.00%
Long-term equity volatilities	25.00%	25.00%
Nonperformance risk spread	0.48%	1.39%
U.S. corporate and foreign corporate securities \| Minimum \| Market Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Delta spread adjustments	(0.35%)	(0.35%)
Offered quotes	68	78
Quoted prices	13	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	103
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	0.47%	0.51%
Offered quotes	487	86
Quoted prices	105	418
RMBS \| Minimum \| Market Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Offered quotes	30	1
RMBS \| Maximum \| Market Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Offered quotes	114	117
RMBS \| Weighted Average \| Market Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Offered quotes	94	93
ABS \| Minimum \| Market Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Offered quotes	64	62
Quoted prices	91	97
ABS \| Maximum \| Market Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Offered quotes	106	106
Quoted prices	109	108
ABS \| Weighted Average \| Market Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Offered quotes	100	99
Quoted prices	100	101

Correlation.

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Fair value inputs long-term equity volatilities.

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- Definition

Swap Yield

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- Definition

Fair value inputs utilization rates.

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- Definition

Fair value inputs withdrawal rates.

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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

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-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

-Section 50

-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

-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.

+ References

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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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