Fair Value Measurements (details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Fair Value Measurements disclosure
Percent of fixed maturities for which a pricing service estimates fair value	98.00%	98.00%
Fair value of the fixed maturities for which the Company used an internal pricing matrix	$ 92	$ 92
Fair value of the fixed maturities for which the Company received a broker quote	$ 120	$ 140
Percent of short-term securities for which a pricing service estimates fair value	99.00%	98.00%
Percent of debt, including commercial paper, for which a pricing service estimates fair value	100.00%	100.00%

The fair value of the fixed maturities for which the Company received a broker quote for use in determining fair value.

No definition available.

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The fair value of the fixed maturities for which the Company used an internal pricing matrix in determining fair value.

No definition available.

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Percentage of debt (including commercial paper) for which a pricing service was used in determining fair value.

No definition available.

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Percentage of fixed maturities for which a pricing service was used in determining fair value.

No definition available.

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Percentage of short-term securities for which a pricing service was used in determining fair value.

No definition available.

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