Net Investment Income (Detail) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018
Net Investment Income [Line Items]
Investment Income	$ 28,968	$ 24,390
Investment Expenses	(749)	(688)
Net Investment Income	28,219	23,702
Fixed Maturities
Net Investment Income [Line Items]
Investment Income	25,015	21,052
Equity Securities
Net Investment Income [Line Items]
Investment Income	3,155	2,925
Short-Term Investments, Cash & Cash Equivalents
Net Investment Income [Line Items]
Investment Income	570	227
Other Invested Assets
Net Investment Income [Line Items]
Investment Income	$ 228	$ 186

Amount, before investment expense, of income earned from investments in securities and real estate. Includes, but is not limited to, real estate investment, policy loans, dividends, and interest. Excludes realized gain (loss) on investments.

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Amount of expenses related to the generation of investment income.

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Amount, after investment expense, of income earned from investments in securities and real estate. Includes, but is not limited to, real estate investment, policy loans, dividends, and interest. Excludes realized gain (loss) on investments.

+ References

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