Note 9 - Segment Reporting (Detail) - Financial Information by Segment (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Revenues	$ 230,594	$ 210,587
Gross profit	52,684	41,174
Operating income (loss)	10,899	5,489
Energy And Mining [Member]
Revenues	115,038	95,457
Gross profit	26,899	23,091
Operating income (loss)	7,440	6,390
North American Water and Wastewater [Member]
Revenues	74,338	81,861
Gross profit	14,571	11,143
Operating income (loss)	4,190	(1,675)
European Water and Wastewater [Member]
Revenues	16,077	20,760
Gross profit	3,352	4,523
Operating income (loss)	(286)	601
Asia-Pacific Water and Wastewater [Member]
Revenues	10,594	12,509
Gross profit	254	2,417
Operating income (loss)	(1,792)	173
Commercial And Structural [Member]
Revenues	14,547
Gross profit	7,608
Operating income (loss)	$ 1,347