Goodwill and Identified Intangible Assets - Goodwill (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2016 USD ($)
Goodwill [Roll Forward]
Goodwill, gross	$ 344,116
Accumulated impairment losses	(94,996)
Goodwill, beginning balance	249,120
Additions to goodwill through acquisitions	46,978
Foreign currency translation	1,125
Goodwill, gross	392,219
Accumulated impairment losses	(94,996)
Goodwill, ending balance	297,223
Infrastructure Solutions
Goodwill [Roll Forward]
Goodwill, gross	190,525
Accumulated impairment losses	(16,069)
Goodwill, beginning balance	174,456
Additions to goodwill through acquisitions	46,978
Foreign currency translation	347
Goodwill, gross	237,850
Accumulated impairment losses	(16,069)
Goodwill, ending balance	221,781
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	778
Goodwill, gross	74,123
Accumulated impairment losses	(45,400)
Goodwill, ending balance	28,723
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	43,800
Goodwill, ending balance	43,799
Fyfe Europe
Goodwill [Roll Forward]
Additions to goodwill through acquisitions	2,400
Goodwill, ending balance	2,437
LMJ
Goodwill [Roll Forward]
Additions to goodwill through acquisitions	700
Goodwill, ending balance	$ 742