Retirement Plans - Information Pertaining to Activity in Supplemental Retirement Plans (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Change in benefit obligation:
Benefit obligation at beginning of year	$ (43,834)	$ (46,197)
Acquisition of obligations	(3,310)	0
Service cost	(1,624)	(1,103)	$ (2,830)
Interest cost	(1,731)	(1,518)	(1,224)
Actuarial (loss)/gain	10,266	3,580
Plan amendments	(2,141)	0
Benefits paid	2,033	1,404
Benefit obligation at end of year	(40,341)	(43,834)	$ (46,197)
Change in plan assets:
Fair value of plan assets at beginning of year	0
Fair value of plan assets at end of year	0	0
Funded status	(40,341)	(43,834)
Unrecognized net obligation existing at January 1, 1986	0	0
Unrecognized net actuarial (loss)/gain	(13,901)	(2,453)
Unrecognized prior service cost	0	(28)
Accumulated other comprehensive loss	13,901	2,481
Accrued benefit cost	(40,341)	(43,834)
Accumulated benefit obligation	$ (40,340)	$ (42,590)