Note 4 - Goodwill and Intangible Assets (Detail) - Reconciliation Goodwill (USD $)	3 Months Ended
	Mar. 31, 2013
Goodwill	$ 273,661,000
Additions to goodwill through acquisitions (1)	200,000	[1]
Foreign currency translation	(1,200,000)
Goodwill	272,728,000	[2]
Energy And Mining [Member]
Goodwill	78,100,000
Additions to goodwill through acquisitions (1)		[1]
Foreign currency translation	(200,000)
Goodwill	77,900,000	[2]
North American Water and Wastewater [Member]
Goodwill	101,900,000
Additions to goodwill through acquisitions (1)		[1]
Foreign currency translation	(100,000)
Goodwill	101,800,000	[2]
International Water and Wastewater [Member]
Goodwill	28,100,000
Additions to goodwill through acquisitions (1)		[1]
Foreign currency translation	(800,000)
Goodwill	27,300,000	[2]
Commercial And Structural [Member]
Goodwill	65,600,000
Additions to goodwill through acquisitions (1)	200,000	[1]
Foreign currency translation	(100,000)
Goodwill	$ 65,700,000	[2]

[1] During 2013, the Company recorded an increase of goodwill of $0.2 million related to the Fyfe Asia acquisition.

[2] The Company does not have any accumulated impairment charges.