Goodwill and Other Intangible Assets (Schedule of Intangible Assets) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
Mar. 31, 2015	Dec. 31, 2014
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	109,407	95,771
Finite-Lived Intangible Assets, Accumulated Amortization	15,761	13,637
Intangible Assets, Net (Excluding Goodwill)	93,646us-gaap_FiniteLivedIntangibleAssetsNet	82,134us-gaap_FiniteLivedIntangibleAssetsNet
Non-compete agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	4,786	4,143
Finite-Lived Intangible Assets, Accumulated Amortization	941	705
Intangible Assets, Net (Excluding Goodwill)	3,845	3,438
Patents [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	523	564
Finite-Lived Intangible Assets, Accumulated Amortization	163	189
Intangible Assets, Net (Excluding Goodwill)	360	375
Customer relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	54,247	44,450
Finite-Lived Intangible Assets, Accumulated Amortization	5,579	4,679
Intangible Assets, Net (Excluding Goodwill)	48,668	39,771
Supplier relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	350	350
Finite-Lived Intangible Assets, Accumulated Amortization	285	268
Intangible Assets, Net (Excluding Goodwill)	65	82
Trademarks and trade names [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	11,616	10,765
Finite-Lived Intangible Assets, Accumulated Amortization	2,093	1,855
Intangible Assets, Net (Excluding Goodwill)	9,523	8,910
Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	37,885	35,499
Finite-Lived Intangible Assets, Accumulated Amortization	6,700	5,941
Intangible Assets, Net (Excluding Goodwill)	31,185	29,558
Rail Products and Services Segment [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	58,417	44,781
Construction Products Segment [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	3,178	3,178
Tubular and Energy Services Segments [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	47,812	47,812
Weighted Average [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	15 years
Weighted Average [Member] \| Non-compete agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	5 years	5 years
Weighted Average [Member] \| Patents [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	10 years	10 years
Weighted Average [Member] \| Customer relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	17 years	19 years
Weighted Average [Member] \| Supplier relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	5 years	5 years
Weighted Average [Member] \| Trademarks and trade names [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	14 years	14 years
Weighted Average [Member] \| Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	14 years	14 years

Accumulated amount of 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=26713463&loc=d3e16323-109275

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