Other Income (Expense) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Other Income and Expenses [Abstract]
Income from Third Party License Fees	$ 861	$ 978	$ 875
Foreign Exchange Gains (Losses), Net	891	172	(1,184)
(Loss) Gain on Fixed Asset Disposals, Net	(79)	50	6
Non-Income Tax Refunds and Other Related Credits	1,015	398	141
Pension And Post Retirement Benefit Costs Nonservice Components	4,234	2,302	3,308
Insurance Solvency Recovery	600	0	0
Other Nonoperating Income	380	338	261
Other Nonoperating Expense	(152)	(126)	(168)
Other Income (Expense), Net	$ (718)	$ (492)	$ (3,377)