Significant Accounting Policies - Accumulated Other Comprehensive Income (Loss) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning balance	$ 37,397	$ 60,787	$ 59,237
Total other comprehensive income (loss)	6,665	(30,614)	(5,311)
Ending balance	49,441	37,397	60,787
Unrealized Holding Gains on Available-for-Sale Securities (Net) [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning balance	(31,765)	(1,151)	4,160
Accumulated other comprehensive income (loss) before reclassification, net of ($1,993), $9,161 and $1,373 tax effect, respectively	6,631	(30,689)	(4,533)
Amounts reclassified from accumulated other comprehensive income, net of ($8), ($16), and $213 tax effects, respectively	34	75	(778)
Total other comprehensive income (loss)	6,665	(30,614)	(5,311)
Ending balance	$ (25,100)	$ (31,765)	$ (1,151)