General - Contributions to Revenues and Profits Since Acquisitions (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Environmental Techniques
Business Acquisition [Line Items]
Revenues	$ 451
Net income (loss)	(102)
Underground Solutions
Business Acquisition [Line Items]
Revenues	6,525	$ 4,666
Net income (loss)	(1,319)	(124)
Inventory step up expense		$ 1,200
Fyfe Europe
Business Acquisition [Line Items]
Revenues	259
Net income (loss)	(58)
LMJ
Business Acquisition [Line Items]
Revenues	1,337
Net income (loss)	(597)
Concrete Solutions
Business Acquisition [Line Items]
Revenues	1,383
Net income (loss)	50
Corporate, Non-Segment | Underground Solutions
Business Acquisition [Line Items]
Net income (loss)	$ (400)