Description of Business - Contributions to Revenues and Profits Since Acquisitions (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Business Acquisition [Line Items]
Restructuring and related charges	$ 12,814	$ 9,168	$ 968
Goodwill impairment	45,390	0	43,484
Energy Services
Business Acquisition [Line Items]
Goodwill impairment	0		33,500
Schultz
Business Acquisition [Line Items]
Revenues	71,252	24,702	13,771
Net income (loss)	(891)	(1,068)	(1,470)
Restructuring and related charges		200
Schultz | Energy Services
Business Acquisition [Line Items]
Goodwill impairment			1,700
Underground Solutions
Business Acquisition [Line Items]
Revenues	32,063	29,425
Net income (loss)	(3,778)	(2,694)
Inventory step up expense		3,600
Fyfe Europe
Business Acquisition [Line Items]
Revenues	583	23
Net income (loss)	(190)	(764)
LMJ
Business Acquisition [Line Items]
Revenues	3,070	4,865
Net income (loss)	(2,186)	(1,153)
Restructuring and related charges	100
Concrete Solutions
Business Acquisition [Line Items]
Revenues	5,922	2,700
Net income (loss)	(1,940)	106
Goodwill impairment	2,200
Environmental Techniques
Business Acquisition [Line Items]
Revenues	5,270
Net income (loss)	(909)
Corporate, Non-Segment | Schultz
Business Acquisition [Line Items]
Net income (loss)	(6,800)	(2,900)	$ (1,000)
Corporate, Non-Segment | Underground Solutions
Business Acquisition [Line Items]
Net income (loss)	$ (4,500)	$ (3,200)