Other Income, Net (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Other Income and Expenses [Abstract]
Other Nonoperating Income	$ 2	$ 0
Other Nonoperating Expense	0	(2)
Defined Benefit Plan, Non-service Costs	(636)	(749)
Interest Income (Expense), Nonoperating, Net	(58)	45
Insurance policy expense	(12)	(12)
Other (expense), net	$ (704)	$ (718)