Goodwill and Other Intangible Assets (Schedule of Goodwill) (Details) $ in Thousands	3 Months Ended
Mar. 31, 2018 USD ($)
Goodwill
Goodwill, beginning balance	$ 19,785
Foreign currency translation impact	344
Goodwill, ending balance	20,129
Rail Products and Services
Goodwill
Goodwill, beginning balance	14,638
Foreign currency translation impact	344
Goodwill, ending balance	14,982
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

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6388280&loc=d3e13770-109266

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=77989000&loc=SL49117168-202975

Name:	us-gaap_Goodwill
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant