Comprehensive Income (Loss) - Schedule of Components of Other Comprehensive Income or Loss and Related Tax Effects Allocated to Each Component (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Before Tax
Net unrealized (losses) gains arising during the period	$ 4,818	$ (11,355)	$ (692)
Call and repayment gains charged to investment income	0	0	(36)
Reclassification adjustment for net realized losses (gains)	1,029	429	(687)
Total other comprehensive loss	5,847	(10,926)	(1,415)
Income Tax Effect
Net unrealized (losses) gains	(1,372)	(263)	(170)
Call and repayment gains charged to investment income			9
Reclassification adjustment for net realized losses (gains)	258	109	(168)
Total other comprehensive loss	(1,114)	(154)	(347)
Net of Tax
Net unrealized (losses) gains	6,190	(11,092)	(522)
Call and repayment gains charged to investment income			27
Reclassification adjustment for net realized gains	771	320	(519)
Total other comprehensive (loss) income, net of income taxes	$ 6,961	$ (10,772)	$ (1,068)