Schedule VI. Supplemental Information Concerning Property-Casualty Insurance Operations (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
SEC Schedule, 12-18, Supplemental Information, Property-Casualty Insurance Underwriters [Abstract]
Deferred Policy Acquisition Costs	$ 17,401	$ 17,059	$ 17,810
Reserves for Unpaid Loss and Loss Adjustment Expense	696,037	745,278	760,561
Unearned Premium	114,976	121,092	129,260
Net Premiums Earned	271,698	275,993	304,427
Net Investment Income	27,223	25,435	29,364
Loss and LAE Related to Current Period	192,907	222,715	220,710
Loss and LAE Related to Prior Periods	(40,591)	(61,917)	(63,484)
Amortization of Deferred Policy Acquisition Costs	(39,852)	(38,481)	(41,583)
Paid Claims and Claim Adjustment Expenses	194,846	189,640	179,916
Net Premiums Written	$ 265,583	$ 267,825	$ 292,814