Benefit Plans - Components of Net Periodic Postretirement Benefit Cost (Detail) - Postretirement Benefits [Member] - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 02, 2016	Sep. 27, 2015	Oct. 02, 2016	Sep. 27, 2015
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 350	$ 325	$ 1,050	$ 975
Interest cost	778	708	2,333	2,123
Recognized net actuarial loss	587	717	1,762	2,152
Amortization of prior service cost	(840)	(840)	(2,520)	(2,520)
Net periodic pension cost	$ 875	$ 910	$ 2,625	$ 2,730