Benefit Plans - Components of Net Periodic Plan Cost for Retirement Plan (Detail) - Director's Retirement Plan - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 0	$ 0	$ 22
Interest cost	0	0	16
Net periodic postretirement cost	$ 0	$ 0	$ 38