Pension Information - Components of Net Periodic Pension Cost (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Compensation And Retirement Disclosure [Abstract]
Service cost	$ 0	$ 0	$ 0	$ 0
Interest cost	121	128	363	384
Expected return on plan assets	(187)	(256)	(561)	(768)
Other components	72	147	217	441
Net periodic pension cost	$ 6	$ 19	$ 19	$ 57