Schedule of Net Periodic Pension and Postretirement benefit Cost (Income) (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 01, 2018	Jul. 02, 2017	Jul. 01, 2018	Jul. 02, 2017
Defined Benefit Plan Disclosure
Net actuarial loss (gain)			$ (71)	$ (2,504)
Settlement loss	$ 100		100
UNITED STATES
Defined Benefit Plan Disclosure
Service cost	545	$ 560	1,116	1,120
Interest cost	2,430	3,264	5,427	6,576
Expected return on plan assets	(2,550)	(3,004)	(5,919)	(6,004)
Amortization of prior service cost	14	18	29	35
Net actuarial loss (gain)	(189)	(2,732)	(189)	(2,732)
Settlement loss	78		78
Total	328	(1,894)	542	(1,005)
Foreign Pension Plans, Defined Benefit
Defined Benefit Plan Disclosure
Service cost	200	206	426	392
Interest cost	175	179	372	342
Expected return on plan assets	(5)	(6)	(10)	(12)
Amortization of prior service cost		243
Net actuarial loss (gain)				243
Total	370	622	788	965
Postretirement Benefit Plans
Defined Benefit Plan Disclosure
Service cost	10	7	19	17
Interest cost	48	50	98	100
Amortization of prior service credit	(93)	(124)	(187)	(248)
Net actuarial loss (gain)	40	(15)	40	(15)
Special termination benefits	1,192		2,818
Total	$ 1,197	$ (82)	$ 2,788	$ (146)