Note 2 - Accounting Policies (Details) - Financial Data for Investments in Affiliated Companies (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013		Sep. 30, 2012
Financial Data for Investments in Affiliated Companies [Abstract]
Revenue			$ 75,986	[1]	$ 102,407
Gross profit			21,753	[1]	28,620
Net income			13,624	[1]	15,382
Equity in earnings of affiliated companies	$ 1,691	$ 2,001	$ 3,903	[1]	$ 4,389

[1] Includes the financial data of Insituform-Germany through the date of its sale in June 2013.