Pension and Postretirement Benefits (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Oct. 01, 2017	Sep. 30, 2018	Oct. 01, 2017	Dec. 31, 2017
Defined Benefit Plan Plan Amendment [Abstract]
Defined benefit plan accumulated benefit obligation increase for plan amendment			$ 35,192
Date of resolution approval plan termination			February 2018
U.S. pension plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Weighted average discount rate	3.20%		3.20%		3.70%
Unrecognized losses, U.S. pension plan, remaining in accumulated other comprehensive loss	$ (142,997)		$ (142,997)
Pension [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	678	$ 925	2,030	$ 2,798
Interest cost	3,997	4,443	11,993	13,598
Expected return on assets	(5,190)	(5,896)	(15,569)	(18,057)
Net amortization and deferrals	2,971	2,525	8,913	7,738
Net periodic benefit cost	2,456	1,997	7,367	6,077
Contributions to defined benefit pension plans			770
Expected fiscal year defined benefit pension plan contributions			1,300
Postretirement [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	189	172	566	517
Interest cost	292	295	877	885
Expected return on assets	0	0	0	0
Net amortization and deferrals	42	0	127	0
Net periodic benefit cost	$ 523	$ 467	$ 1,570	$ 1,402