Schedule Of Percentages Of Investments By Major Components At Fair Value (Detail)	Dec. 31, 2012
Commitments And Contingencies [Abstract]
Investment-grade corporate securities	78.00%
Securities of state and municipal governments	10.00%
Below-investment-grade securities	4.00%
Policy loans, which are secured by the underlying insurance policy values	3.00%
Government-sponsored enterprises	3.00%
Other fixed maturities, equity securities, mortgages, real estate, other long-term investments, and short-term investments	2.00%
Proportion Of Total Securities At Fair Value In Investment Portfolio, Total	100.00%

Proportion Of Below Investment Grade Securities At Fair Value In Investment Portfolio

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Proportion Of Government Sponsored Enterprises At Fair Value In Investment Portfolio

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Proportion Of Investment Grade Corporate Securities At Fair Value In Investment Portfolio

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Proportion Of Long Term Investments At Fair Value In Investment Portfolio

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Proportion Of Policy Loans

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Proportion Of State And Municipal Governments Securities At Fair Value In Investment Portfolio

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Proportion Of Total Securities At Fair Value In Investment Portfolio

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