Note 4 - Goodwill and Intangible Assets (Detail) - Schedule of Goodwill (USD $)	3 Months Ended		12 Months Ended
	Mar. 31, 2012		Dec. 31, 2011
Goodwill	$ 251,275,000	[1]	$ 249,888,000	[1]
Goodwill	249,888,000	[1]	190,100,000
Additions to goodwill through acquisitions(1)(2)	100,000	[2]	63,700,000	[3]
Foreign currency translation	1,300,000		(3,900,000)
Goodwill	251,275,000	[1]	249,888,000	[1]
Energy And Mining [Member]
Goodwill	76,400,000		77,400,000
Goodwill	76,400,000		77,400,000
North American Water and Wastewater [Member]
Goodwill	101,900,000		101,800,000
Goodwill	101,900,000		101,800,000
European Water and Wastewater [Member]
Goodwill	22,400,000		21,800,000
Goodwill	22,400,000		21,800,000
Asia-Pacific Water and Wastewater [Member]
Goodwill	5,800,000		5,700,000
Goodwill	5,800,000		5,700,000
Commercial And Structural [Member]
Goodwill	44,800,000		43,200,000
Goodwill	$ 44,800,000		$ 43,200,000

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

[2] During the first quarter of 2012, the Company recorded goodwill of $1.7 million related to the acquisition of Fyfe LA and decreases of $1.5 million and $0.2 million in goodwill related to the 2011 acquisitions of Hockway and Fyfe NA.

[3] During the year ended December 31, 2011, the Company recorded goodwill of $18.5 million related to the acquisition of CRTS, $2.0 million related to the acquisition of Hockway and $43.2 million related to the acquisition of Fyfe NA as discussed in Note 1.