Investments - Gross Unrealized Gains and Losses and Cost or Amortized Cost, Allowance for Credit Losses and Fair Value of Investments Classified as Available-for-Sale (Detail) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale, Amortized Cost	$ 351,118	$ 324,597
Available-for-sale, Gross Unrealized Gains	124	17,829
Available-for-sale, Gross Unrealized Losses	(25,351)	(657)
Fixed maturity securities-available-for-sale	325,891	341,769
Debt Securities Available For Sale Allowance For Credit Loss	0	0
States and Political Subdivisions [Member]
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale, Amortized Cost	180,244	202,008
Available-for-sale, Gross Unrealized Gains	118	14,538
Available-for-sale, Gross Unrealized Losses	(14,201)	(240)
Fixed maturity securities-available-for-sale	166,161	216,306
Corporate Bonds [Member]
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale, Amortized Cost	149,008	93,947
Available-for-sale, Gross Unrealized Gains		2,751
Available-for-sale, Gross Unrealized Losses	(8,960)	(272)
Fixed maturity securities-available-for-sale	140,048	96,426
U.S. Agency-Based Mortgage-Backed Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale, Amortized Cost	6,208	7,944
Available-for-sale, Gross Unrealized Gains		158
Available-for-sale, Gross Unrealized Losses	(629)	(13)
Fixed maturity securities-available-for-sale	5,579	8,089
U.S. Treasury Securities and Obligations of U.S. Government Agencies [Member]
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale, Amortized Cost	15,658	20,698
Available-for-sale, Gross Unrealized Gains	6	382
Available-for-sale, Gross Unrealized Losses	(1,561)	(132)
Fixed maturity securities-available-for-sale	$ 14,103	$ 20,948

Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount, before tax, of unrealized loss in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount of allowance for credit loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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