Benefit Plans - Components of Net Periodic Postretirement Benefit Cost (Detail) - Net Postretirement Benefits Activity [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 29, 2019	Dec. 30, 2018	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 1,496	$ 1,854	$ 2,232
Interest cost	2,750	2,694	3,636
Recognized net actuarial loss	730	1,889	2,942
Amortization of prior service cost	(1,293)	(1,847)	(2,982)
Net periodic pension cost	$ 3,683	$ 4,590	$ 5,828