Goodwill and Identified Intangible Assets - Goodwill (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2016 USD ($)
Goodwill [Roll Forward]
Goodwill, gross	$ 344,116
Accumulated impairment losses	(94,996)
Goodwill, beginning balance	249,120
Additions to goodwill through acquisitions	43,621
Foreign currency translation	1,738
Goodwill, gross	389,475
Accumulated impairment losses	(94,996)
Goodwill, ending balance	294,479
Infrastructure Solutions
Goodwill [Roll Forward]
Goodwill, gross	190,525
Accumulated impairment losses	(16,069)
Goodwill, beginning balance	174,456
Additions to goodwill through acquisitions	43,621
Foreign currency translation	1,138
Goodwill, gross	235,284
Accumulated impairment losses	(16,069)
Goodwill, ending balance	219,215
Corrosion Protection
Goodwill [Roll Forward]
Goodwill, gross	73,345
Accumulated impairment losses	(45,400)
Goodwill, beginning balance	27,945
Additions to goodwill through acquisitions	0
Foreign currency translation	600
Goodwill, gross	73,945
Accumulated impairment losses	(45,400)
Goodwill, ending balance	28,545
Energy Services
Goodwill [Roll Forward]
Goodwill, gross	80,246
Accumulated impairment losses	(33,527)
Goodwill, beginning balance	46,719
Additions to goodwill through acquisitions	0
Foreign currency translation	0
Goodwill, gross	80,246
Accumulated impairment losses	(33,527)
Goodwill, ending balance	46,719
Underground Solutions
Goodwill [Roll Forward]
Additions to goodwill through acquisitions	43,600
Goodwill, ending balance	$ 43,621