Segment Reporting - Financial Information by Segment (Details) - USD ($)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Segment Reporting Information [Line Items]
Revenues	$ 354,473,000	$ 297,686,000	$ 679,648,000	$ 591,594,000
Gross profit	79,768,000	61,190,000	147,180,000	115,604,000
Operating income	21,659,000	8,145,000	35,792,000	4,006,000
Interest expense	(4,005,000)	(3,641,000)	(8,052,000)	(7,256,000)
Interest income	35,000	128,000	84,000	160,000
Other	(408,000)	(498,000)	(795,000)	(1,471,000)
Total other expense	(4,378,000)	(4,011,000)	(8,763,000)	(8,567,000)
Income (loss) before taxes on income	17,281,000	4,134,000	27,029,000	(4,561,000)
Restructuring charges	0	1,535,000	0	8,332,000
Acquisition-related expenses	0	(704,000)	(533,000)	(1,735,000)
Restructuring Plan 2016
Segment Reporting Information [Line Items]
Other		300,000		300,000
Restructuring charges		3,763,000	0	13,505,000	$ 16,100,000
Restructuring charges, net				13,300,000
Underground Solutions
Segment Reporting Information [Line Items]
Inventory step up expense		2,400,000		3,600,000
Infrastructure Solutions | Restructuring Plan 2016
Segment Reporting Information [Line Items]
Restructuring charges		1,219,000		3,372,000
Restructuring charges, net		1,000,000		3,100,000
Infrastructure Solutions | Environmental Techniques
Segment Reporting Information [Line Items]
Acquisition-related expenses			(500,000)
Infrastructure Solutions | Underground Solutions
Segment Reporting Information [Line Items]
Acquisition-related expenses		(700,000)		(1,700,000)
Inventory step up expense		2,400,000
Corrosion Protection | Restructuring Plan 2016
Segment Reporting Information [Line Items]
Restructuring charges		957,000		3,694,000
Energy Services | Restructuring Plan 2016
Segment Reporting Information [Line Items]
Restructuring charges		1,587,000		6,439,000
Operating Segments | Infrastructure Solutions
Segment Reporting Information [Line Items]
Revenues	148,311,000	150,199,000	277,179,000	275,961,000
Gross profit	34,364,000	39,175,000	65,615,000	68,919,000
Operating income	8,391,000	13,067,000	14,001,000	18,875,000
Operating Segments | Corrosion Protection
Segment Reporting Information [Line Items]
Revenues	127,715,000	94,410,000	251,105,000	186,856,000
Gross profit	35,636,000	17,103,000	63,599,000	34,302,000
Operating income	11,239,000	(2,469,000)	18,451,000	(8,139,000)
Operating Segments | Energy Services
Segment Reporting Information [Line Items]
Revenues	78,447,000	53,077,000	151,364,000	128,777,000
Gross profit	9,768,000	4,912,000	17,966,000	12,383,000
Operating income	$ 2,029,000	$ (2,453,000)	$ 3,340,000	$ (6,730,000)