Note 1 - Description of Business (Detail) - Business Acquisitions - Continued Purchase Price Allocation (USD $) In Thousands, unless otherwise specified	12 Months Ended		12 Months Ended		12 Months Ended
	Dec. 31, 2011 CRTS [Member]	Jun. 30, 2011 CRTS [Member]	Dec. 31, 2011 Hockway [Member]	Aug. 31, 2011 Hockway [Member]	Dec. 31, 2011 Fyfe NA [Member]	Aug. 31, 2011 Fyfe NA [Member]
Total identifiable net assets at acquisition date	$ 19,883	$ 20,267	$ 4,551	$ 4,078	$ 69,704	$ 75,074
Receivables and cost and estimated earnings in excess of billings			(409)
Inventories			(64)
Property, plant and equipment	4,033				(85)
Identifiable intangible assets	(3,105)				5,633
Accounts payable, accrued expenses and billings in excess of cost and estimated earnings	(300)				(916)
Deferred tax liabilities	(244)
Other adjustments					738
Total identifiable net assets at December 31, 2011	20,267	20,267	4,078	4,078	75,074	75,074
Goodwill at acquisition dates	18,017	18,493	1,524	1,982	46,082	43,239
Increase (decrease) in goodwill related to acquisitions	476		458		(2,843)
Goodwill at December 31, 2011	$ 18,493	$ 18,493	$ 1,982	$ 1,982	$ 43,239	$ 43,239