Employee Benefit Plans - Components of Net Periodic Pension Cost for Defined Benefit Pension Plan and Retirement Plan (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 27, 2020	Jun. 29, 2019	Jun. 27, 2020	Jun. 29, 2019
Retirement Benefits [Abstract]
Service cost	$ 156	$ 126	$ 311	$ 251
Interest cost	303	347	605	694
Expected return on plan assets	(441)	(411)	(881)	(822)
Amortization of actuarial losses	247	221	496	443
Net periodic pension cost	$ 265	$ 283	$ 531	$ 566