Goodwill and Other Intangible Assets (Schedule of Goodwill) (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2018 USD ($)
Goodwill
Goodwill, beginning balance	$ 19,785
Foreign currency translation impact	(219)
Goodwill, ending balance	19,566
Rail Products and Services
Goodwill
Goodwill, beginning balance	14,638
Foreign currency translation impact	(219)
Goodwill, ending balance	14,419
Construction Products
Goodwill
Goodwill, beginning balance	5,147
Foreign currency translation impact	0
Goodwill, ending balance	5,147
Tubular and Energy Services
Goodwill
Goodwill, beginning balance	0
Foreign currency translation impact	0
Goodwill, ending balance	$ 0