Investments - Major Categories of the Company's Net Investment Income (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Schedule Of Investment Income Reported Amounts By Category [Line Items]
Total gross investment income	$ 29,421	$ 31,293	$ 32,269
Investment expenses	(2,428)	(2,081)	(930)
Net investment income	26,993	29,212	31,339
Fixed Maturity Securities Available for Sale [Member]
Schedule Of Investment Income Reported Amounts By Category [Line Items]
Total gross investment income	25,980	26,341	26,357
Equity Securities [Member]
Schedule Of Investment Income Reported Amounts By Category [Line Items]
Total gross investment income	743	1,003	1,456
Short-term Investments [Member]
Schedule Of Investment Income Reported Amounts By Category [Line Items]
Total gross investment income	$ 2,698	$ 3,949	$ 4,456