Segment Reporting - Financial Information by Segment (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Segment Reporting Information [Line Items]
Revenues	$ 356,595	$ 350,138	$ 1,002,857	$ 979,240
Gross profit	77,121	63,939	208,364	196,920
Operating income	24,938	(13,934)	48,586	15,819
Restructuring Plan 2014 [Member]
Segment Reporting Information [Line Items]
Charges related to restructuring		39,953		39,953
Infrastructure Solutions [Member] \| Restructuring Plan 2014 [Member]
Segment Reporting Information [Line Items]
Charges related to restructuring	1,498		10,730	17,800
Infrastructure Solutions [Member] \| Restructuring Plan 2014 [Member] \| Gross Profit [Member]
Segment Reporting Information [Line Items]
Charges related to restructuring	1,700	3,600	2,600	3,600
Infrastructure Solutions [Member] \| Restructuring Plan 2014 [Member] \| Operating Income [Member]
Segment Reporting Information [Line Items]
Charges related to restructuring	1,400	17,700	7,900	17,700
Corrosion Protection [Member] \| Restructuring Plan 2014 [Member]
Segment Reporting Information [Line Items]
Charges related to restructuring				22,200
Corrosion Protection [Member] \| Restructuring Plan 2014 [Member] \| Gross Profit [Member]
Segment Reporting Information [Line Items]
Charges related to restructuring	11,300
Corrosion Protection [Member] \| Restructuring Plan 2014 [Member] \| Operating Income [Member]
Segment Reporting Information [Line Items]
Charges related to restructuring	22,200
Operating Segments [Member] \| Infrastructure Solutions [Member]
Segment Reporting Information [Line Items]
Revenues	149,606	152,628	421,170	422,212
Gross profit	38,428	34,559	106,074	96,064
Operating income	16,255	(3,729)	35,701	10,605
Operating Segments [Member] \| Corrosion Protection [Member]
Segment Reporting Information [Line Items]
Revenues	121,392	120,157	329,157	331,088
Gross profit	27,595	17,842	70,311	67,017
Operating income	6,886	(14,082)	8,323	(5,114)
Operating Segments [Member] \| Energy Services [Member]
Segment Reporting Information [Line Items]
Revenues	85,597	77,353	252,530	225,940
Gross profit	11,098	11,538	31,979	33,839
Operating income	$ 1,797	$ 3,877	$ 4,562	$ 10,328

Aggregate revenue less cost of goods and services sold or operating expenses directly attributable to the revenue generation activity.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.1,2)

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+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 420

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SAB TOPIC 5.P.4(b))

-URI http://asc.fasb.org/extlink&oid=27011515&loc=d3e140904-122747

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 420

-SubTopic 10

-Section 50

-Paragraph 1

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 5

-Section P

-Subsection 3, 4

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Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

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