Retirement Plans - Components of Net Periodic Benefit (Credits) Costs for Pension and Other Postretirement Benefits (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Apr. 01, 2017
Pension Benefits [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Service cost	$ 573	$ 506
Interest cost	8,781	10,138
Expected return on plan assets	(12,780)	(11,964)
Amortization of prior service cost	1	35
Amortization of net loss (gain)	846	1,051
Net periodic benefit (credits) costs	(2,579)	(234)
Other Postretirement Plans [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Service cost	9	10
Interest cost	59	72
Amortization of prior service cost	2	1
Amortization of net loss (gain)	(39)	(13)
Net periodic benefit (credits) costs	$ 31	$ 70