Goodwill and Identified Intangible Assets - Goodwill (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2015 USD ($)
Goodwill [Roll Forward]
Goodwill, beginning balance	$ 293,023
Additions to goodwill through acquisitions	3,998
Foreign currency translation	(3,872)
Goodwill, ending balance	293,149
Infrastructure Solutions [Member]
Goodwill [Roll Forward]
Goodwill, beginning balance	177,275
Additions to goodwill through acquisitions	0
Foreign currency translation	(2,579)
Goodwill, ending balance	174,696
Corrosion Protection [Member]
Goodwill [Roll Forward]
Goodwill, beginning balance	39,500
Additions to goodwill through acquisitions	0
Foreign currency translation	(1,293)
Goodwill, ending balance	38,207
Energy Services [Member]
Goodwill [Roll Forward]
Goodwill, beginning balance	76,248
Additions to goodwill through acquisitions	3,998
Foreign currency translation	0
Goodwill, ending balance	$ 80,246