Goodwill and Other Intangible Assets (Goodwill Gross) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Goodwill
Goodwill, gross carrying value	$ 88,181	$ 87,003
Rail Products and Services
Goodwill
Goodwill, gross carrying value	57,654	56,476
Construction Products
Goodwill
Goodwill, gross carrying value	1,348	1,348
Tubular and Energy Services
Goodwill
Goodwill, gross carrying value	$ 29,179	$ 29,179

Amount before amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275

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