Retirement Plans - Components of Net Periodic Pension Expense (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Retirement Benefits [Abstract]
Interest cost	$ 454	$ 392	$ 378
Expected return on plan assets	$ (605)	$ (732)	(574)
Net amortization and deferral			$ 240
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) Excluding Service Cost, Statement of Income or Comprehensive Income [Extensible Enumeration]	Other Noninterest Expense	Other Noninterest Expense	Other Noninterest Expense
Net periodic pension cost (benefit)	$ (151)	$ (340)	$ 44
Total pension cost (benefit)	(151)	(340)	44
Net loss (gain) recognized in other comprehensive income	(972)	(736)	(854)
Total recognized in net periodic benefit cost and other comprehensive loss (before tax)	$ (1,123)	$ (1,076)	$ (810)