Note 1 - Description of Business (Detail) (USD $)	6 Months Ended	12 Months Ended									6 Months Ended		5 Months Ended						4 Months Ended	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Oct. 30, 2009 BPPC [Member]	Feb. 28, 2010 Bayou Delta [Member]	Dec. 31, 2009 Bayou Delta [Member]	Apr. 30, 2011 Bayou Wasco [Member]	Apr. 30, 2011 WCU [Member]	Jun. 30, 2011 Corrpower [Member]	Dec. 31, 2011 CRTS [Member]	Jun. 30, 2011 CRTS [Member]	Dec. 31, 2011 Hockway [Member]	Aug. 31, 2011 Hockway [Member]	Oct. 30, 2011 UPS-Aptec Limited [Member]	Oct. 21, 2011 UPS-Aptec Limited [Member]	Dec. 31, 2011 USTS [Member]	Dec. 03, 2009 Insituform Linings [Member]	Dec. 31, 2011 Fyfe NA [Member]	Dec. 31, 2011 Fyfe NA [Member]	Aug. 31, 2011 Fyfe NA [Member]	Jan. 04, 2012 Fyfe LA [Member]
Noncontrolling Interest, Ownership Percentage by Parent					51.00%	59.00%		51.00%		70.00%					51.00%		51.00%
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners						41.00%				30.00%					49.00%		49.00%	25.00%
Equity Method Investment, Ownership Percentage							49.00%		49.00%
Business Acquisition, Cost of Acquired Entity, Purchase Price												$ 24,000,000		$ 4,600,000							$ 115,800,000	$ 2,300,000
Business Acquisition, Contingent Consideration, Potential Cash Payment												15,000,000		1,500,000
Joint Venture Contract Value																67.3
Joint Venture Contract, Miles of Pipeline																135
Business Acquisition, Purchase Price Allocation, Goodwill, Expected Tax Deductible Amount													400,000
Business Combination, Acquisition Related Costs	6,400,000	6,372,000		8,494,000
Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, Low	0	0
Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, High	16.5	16.5
Business Acquisition, Contingent Consideration, at Fair Value	16,214,000	16,214,000									14,800,000	14,760,000	1,500,000	1,454,000
Business Combination, Pro Forma Information, Revenue of Acquiree since Acquisition Date, Actual											6,400,000		2,100,000						17,100,000
Business Combination, Pro Forma Information, Earnings or Loss of Acquiree since Acquisition Date, Actual											200,000		100,000						700,000
Estimated Payments for Previous Acquisition																			2,500,000	2,500,000
Payments for Previous Acquisition																				1,800,000
Business Combination, Contingent Consideration Arrangements, Change in Amount of Contingent Consideration, Liability		$ 1,700,000	$ 1,700,000	$ 1,600,000							$ 900,000		$ 100,000