Pension and Postretirement Benefit Obligations - Components of Net Periodic Postretirement Benefit Cost (Detail) - Postretirement Benefits - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 02, 2021	Jun. 28, 2020	Jul. 02, 2021	Jun. 28, 2020
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 403	$ 376	$ 806	$ 752
Interest cost	448	504	895	1,007
Recognized net actuarial loss	185	87	371	175
Net periodic pension/postretirement benefit cost	$ 1,036	$ 967	$ 2,072	$ 1,934