Retirement Benefit Plans (Narrative) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2016 USD ($) employee plan subsidiary	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Feb. 03, 2006 plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Number of non-contributory defined benefit pension plans | plan				2
Estimate of amount of unrecognized actuarial expense	$ 433
Number of defined contribution plans | plan	2
United States
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Annual contribution amount	$ 1,900	$ 1,871	$ 1,466
Non-US
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Annual contribution amount	$ 735	864	$ 806
Number of international subsidiaries that participate in defined contribution and savings plan | subsidiary	3
IAM Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Annual contribution amount	$ 435	414
Minimum | Non-US
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Employer contribution percentage	3.00%
Maximum | Non-US
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Employer contribution percentage	10.00%
Pension Plans, Defined Benefit
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Amount expenses of accumulated pension actuarial losses	$ 2,889
Underfunded status	(2,929)	(4,499)
Supplemental Employee Retirement Plans, Defined Benefit
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Estimate of amount of unrecognized actuarial expense	$ 406
SERP credited service period	10 years
Percentage of final 3 year average salary in which retirement benefit is based (percentage)	20.00%
Number of final years in which the Retirement Benefit is based	3 years
Retirement age	65 years
Period of time that vested retirement benefit will be paid after death or change in control	90 days
Years of monthly installments associated with SERP disability	15 years
Supplemental Employee Retirement Plans, Defined Benefit | Minimum
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Current retirement benefit percentage	10.00%
Supplemental Employee Retirement Plans, Defined Benefit | Maximum
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Current retirement benefit percentage	20.00%
Hourly Employees’ Pension Plan | Pension Plans, Defined Benefit
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Amount of final contribution	$ 622
Amount expenses of accumulated pension actuarial losses	2,889
Underfunded status	$ 0	(630)
Employees’ Retirement Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Former employees | employee	245
Current employees | employee	78
Employees’ Retirement Plan | Pension Plans, Defined Benefit
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Amount expenses of accumulated pension actuarial losses	$ 0
Underfunded status	$ (2,929)	$ (3,869)