Income Taxes - Schedule of Company's Deferred Income Tax Assets and Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024
Deferred income tax assets:
Discounting of net unpaid loss and loss adjustment expenses	$ 13,744	$ 14,552
Unearned premiums	6,794	6,257
Accrued expenses and other	2,057	2,145
State income tax	2,373	2,501
Accrued policyholder dividends	1,294	1,408
Accrued insurance-related assessments	1,598	1,557
Total deferred tax assets	27,860	28,420
Deferred income tax liabilities:
Deferred policy acquisition costs	(5,167)	(4,737)
Net unrealized gain on securities available-for-sale	(4,674)	(2,389)
Property and equipment and other	(171)	(130)
Salvage and subrogation	(276)	(302)
Loss reserves adjustment	0	(1,414)
Total deferred income tax liabilities	(10,288)	(8,972)
Net deferred income taxes	$ 17,572	$ 19,448