Pension and Postretirement Benefit Obligations - Components of Net Periodic Pension Cost (Detail) - Pension Plans - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 28, 2020	Jun. 30, 2019	Jun. 28, 2020	Jun. 30, 2019
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 1,658	$ 1,206	$ 3,317	$ 2,413
Interest cost	2,760	3,062	5,520	6,125
Expected return on plan assets	(3,383)	(2,574)	(6,766)	(5,148)
Recognized net actuarial loss	1,190	900	2,379	1,801
Amortization of prior service cost	4	7	9	12
Net periodic pension/postretirement benefit cost	$ 2,229	$ 2,601	$ 4,459	$ 5,203