Benefit Plans - Components of Net Periodic Plan Cost for Retirement Plan (Detail) - Director's Retirement Plan - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 0	$ 22	$ 18
Interest cost	0	16	17
Net periodic postretirement cost	$ 0	$ 38	$ 35