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 ($)	Dec. 31, 2025	Dec. 31, 2024
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale, Amortized Cost	$ 317,116,000	$ 318,975,000
Available-for-sale, Gross Unrealized Gains	2,861,000	1,396,000
Available-for-sale, Gross Unrealized Losses	(6,939,000)	(12,621,000)
Fixed maturity securities-available-for-sale, at fair value	313,038,000	307,750,000
Available-for-sale securities, credit allowance	0	0
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	163,042,000	156,488,000
Available-for-sale, Gross Unrealized Gains	630,000	148,000
Available-for-sale, Gross Unrealized Losses	(5,482,000)	(8,430,000)
Fixed maturity securities-available-for-sale, at fair value	158,190,000	148,206,000
Corporate Bonds [Member]
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale, Amortized Cost	137,198,000	143,070,000
Available-for-sale, Gross Unrealized Gains	2,231,000	1,248,000
Available-for-sale, Gross Unrealized Losses	(725,000)	(2,783,000)
Fixed maturity securities-available-for-sale, at fair value	138,704,000	141,535,000
U.S. Agency-Based Mortgage-Backed Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale, Amortized Cost	3,946,000	4,545,000
Available-for-sale, Gross Unrealized Losses	(305,000)	(486,000)
Fixed maturity securities-available-for-sale, at fair value	3,641,000	4,059,000
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	12,930,000	14,872,000
Available-for-sale, Gross Unrealized Losses	(427,000)	(922,000)
Fixed maturity securities-available-for-sale, at fair value	$ 12,503,000	$ 13,950,000