Pension Information - Components of Net Periodic Pension Cost (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Compensation And Retirement Disclosure [Abstract]
Service cost	$ 0	$ 0	$ 0	$ 0
Interest cost	95	121	285	363
Expected return on plan assets	(160)	(187)	(480)	(561)
Other components	81	72	244	217
Net periodic pension cost	$ 16	$ 6	$ 49	$ 19