Goodwill and Other Intangible Assets (Schedule of Gross Other Intangible Assets) (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Gross intangible assets balance by reportable segment	$ 88,683	$ 88,181
Rail Products and Services
Gross intangible assets balance by reportable segment	58,156	57,654
Construction Products
Gross intangible assets balance by reportable segment	1,348	1,348
Tubular and Energy Services
Gross intangible assets balance by reportable segment	$ 29,179	$ 29,179