Schedule of Net Periodic Pension and Postretirement benefit Cost (Income) (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Oct. 01, 2017	Sep. 30, 2018	Oct. 01, 2017
Defined Benefit Plan Disclosure
Net actuarial loss (gain)			$ 196	$ (2,504)
Settlement loss	$ 300		300
UNITED STATES
Defined Benefit Plan Disclosure
Service cost	538	$ 560	1,657	1,679
Interest cost	1,750	3,288	7,188	9,863
Expected return on plan assets	(1,551)	(3,002)	(7,484)	(9,006)
Amortization of prior service cost	14	18	43	53
Net actuarial loss (gain)			(189)	(2,732)
Settlement loss	267		345
Total	1,018	864	1,560	(143)
Foreign Pension Plans, Defined Benefit
Defined Benefit Plan Disclosure
Service cost	203	215	609	606
Interest cost	177	186	532	527
Expected return on plan assets	(5)	(6)	(15)	(19)
Net actuarial loss (gain)				243
Total	375	395	1,126	1,357
Postretirement Benefit Plans
Defined Benefit Plan Disclosure
Service cost	10	8	29	25
Interest cost	49	50	147	151
Amortization of prior service credit	(93)	(124)	(280)	(372)
Net actuarial loss (gain)			40	(15)
Special termination benefits	601		3,419
Total	$ 567	$ (66)	$ 3,355	$ (211)