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	Mar. 31, 2026	Dec. 31, 2025
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale, Amortized Cost	$ 321,312	$ 317,116
Available-for-sale, Gross Unrealized Gains	1,616	2,861
Available-for-sale, Gross Unrealized Losses	(8,717)	(6,939)
Fixed maturity securities-available-for-sale, at fair value	314,211	313,038
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	168,422	163,042
Available-for-sale, Gross Unrealized Gains	334	630
Available-for-sale, Gross Unrealized Losses	(6,887)	(5,482)
Fixed maturity securities-available-for-sale, at fair value	161,869	158,190
Corporate Bonds [Member]
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale, Amortized Cost	142,138	137,198
Available-for-sale, Gross Unrealized Gains	1,282	2,231
Available-for-sale, Gross Unrealized Losses	(1,088)	(725)
Fixed maturity securities-available-for-sale, at fair value	142,332	138,704
U.S. Agency-Based Mortgage-Backed Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale, Amortized Cost	3,811	3,946
Available-for-sale, Gross Unrealized Losses	(317)	(305)
Fixed maturity securities-available-for-sale, at fair value	3,494	3,641
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	6,941	12,930
Available-for-sale, Gross Unrealized Losses	(425)	(427)
Fixed maturity securities-available-for-sale, at fair value	$ 6,516	$ 12,503

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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