Accumulated Other Comprehensive Income (Loss) (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2018 USD ($)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	$ (4,710)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	(564)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	84
Ending Balance	(5,190)
Accumulated Currency Translation [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(838)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	(564)
Ending Balance	(1,402)
Accumulated Postretirement Transactions [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(3,872)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	84
Ending Balance	$ (3,788)