Note 4 - Goodwill and Intangible Assets (Details) - Reconciliation Goodwill (USD $)	6 Months Ended
	Jun. 30, 2014
Goodwill [Line Items]
Goodwill, Acquired During Period	$ 1,100,000
Goodwill [Roll Forward]
Goodwill	348,680,000
Foreign currency translation	98,000
Goodwill	349,912,000
Energy And Mining [Member]
Goodwill [Line Items]
Goodwill, Acquired During Period	0
Goodwill [Roll Forward]
Goodwill	153,110,000
Foreign currency translation	(149,000)
Goodwill	152,961,000
Water and Wastewater [Member]
Goodwill [Line Items]
Goodwill, Acquired During Period	0
Goodwill [Roll Forward]
Goodwill	130,078,000
Foreign currency translation	182,000
Goodwill	130,260,000
Commercial And Structural [Member]
Goodwill [Line Items]
Goodwill, Acquired During Period	1,100,000
Goodwill [Roll Forward]
Goodwill	65,492,000
Foreign currency translation	65,000
Goodwill	$ 66,691,000