Pension and Other Postretirement Obligations - Components of Net Periodic Benefit Costs (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 01, 2017	Oct. 02, 2016	Oct. 01, 2017	Oct. 02, 2016
Pension Obligations
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 1,206	$ 1,282	$ 3,549	$ 4,118
Interest cost	1,822	2,202	5,391	7,020
Expected return on plan assets	(2,487)	(2,931)	(7,415)	(9,339)
Amortization of prior service credit	(10)	(11)	(30)	(29)
Actuarial losses	633	659	1,866	2,067
Settlement loss	0	7,385	0	7,385
Net periodic benefit cost	1,164	8,586	3,361	11,222
Other Postretirement Obligations
Defined Benefit Plan Disclosure [Line Items]
Service cost	14	11	41	40
Interest cost	344	305	1,000	1,152
Expected return on plan assets	0	0	0	0
Amortization of prior service credit	0	(11)	0	(33)
Actuarial losses	23	29	68	260
Settlement loss	0	0	0	0
Net periodic benefit cost	$ 381	$ 334	$ 1,109	$ 1,419