Benefit Plans - Components of Net Periodic Postretirement Benefit Cost (Detail) - Postretirement Benefits [Member] - USD ($) $ in Thousands	12 Months Ended
	Jan. 01, 2017	Jan. 03, 2016	Dec. 28, 2014
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 1,567	$ 1,118	$ 1,445
Interest cost	3,094	2,878	3,255
Recognized net actuarial loss	2,186	3,164	2,293
Amortization of prior service cost	(3,360)	(3,360)	(1,513)
Net periodic pension cost (benefit)	$ 3,487	$ 3,800	$ 5,480