Schedule of Net Periodic Pension and Postretirement Cost (Benefit) (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 30, 2014	Mar. 31, 2013
Defined Benefit Pension Plans
Defined Benefit Plan Disclosure
Service cost	$ 796	$ 834
Interest cost	3,720	3,370
Expected return on plan assets	(3,342)	(3,630)
Amortization of unrecognized prior service benefit	34	41
Total net periodic pension/ postretirement cost (benefit)	1,208	615
Postretirement Benefit Plans
Defined Benefit Plan Disclosure
Service cost	13	16
Interest cost	86	87
Amortization of unrecognized prior service benefit	(150)	(150)
Total net periodic pension/ postretirement cost (benefit)	$ (51)	$ (47)