Segment and Geographic Information - Financial Information by Segment (Details) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018 USD ($)	Sep. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Sep. 30, 2017 USD ($)	Jun. 30, 2017 USD ($)	Mar. 31, 2017 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($) lawsuit
Segment Reporting Information [Line Items]
Revenues	$ 333,998	$ 339,679	$ 335,030	$ 324,861	$ 337,499	$ 341,872	$ 354,473	$ 325,175	$ 1,333,568	$ 1,359,019	$ 1,221,920
Gross profit	61,696	72,673	71,053	61,504	64,190	73,442	79,768	67,412	266,926	284,812	253,927
Operating income (loss)	(1,002)	$ 13,009	$ 14,459	$ 3,181	(3,956)	(75,271)	$ 21,495	$ 14,212	29,647	(43,520)	50,791
Interest expense									(17,327)	(16,001)	(15,029)
Interest income									516	145	166
Other									(9,881)	(2,201)	(694)
Total other expense									(26,692)	(18,057)	(15,557)
Income (loss) before taxes on income									2,955	(61,577)	35,234
Total assets	992,417				1,107,099				992,417	1,107,099	1,193,582
Capital expenditures									30,514	30,830	38,760
Depreciation and amortization									37,855	44,419	46,719
Goodwill impairment									1,389	45,390	0
Restructuring and related charges									(6,894)	(12,814)	(9,168)
Gain on litigation settlement									0	0	6,625
Acquisition and divestiture expenses									(7,004)	(2,923)	(2,696)
Infrastructure Solutions
Segment Reporting Information [Line Items]
Revenues									604,121	612,154	571,551
Gross profit									132,411	140,823	142,444
Operating income (loss)									23,683	(62,244)	53,899
Restructuring charges, net									16,900	18,100
Acquisition-related expenses									800
Goodwill impairment						45,400			1,389	45,390
Impairment of intangible assets						$ 41,000				41,000
Restructuring and related charges											(2,900)
Inventory step up expense											3,600
Gain on litigation settlement											$ 6,600
Number of lawsuits settled | lawsuit											2
Corrosion Protection
Segment Reporting Information [Line Items]
Revenues									393,740	456,139	$ 401,469
Gross profit									92,968	108,240	83,269
Operating income (loss)									(1,867)	12,446	1,458
Restructuring charges, net									8,300	5,900
Goodwill impairment									0	0
Energy Services
Segment Reporting Information [Line Items]
Revenues									335,707	290,726	248,900
Gross profit									41,547	35,749	28,214
Operating income (loss)									7,831	6,278	(4,566)
Restructuring charges, net									400
Goodwill impairment									0	0
Operating Segments | Infrastructure Solutions
Segment Reporting Information [Line Items]
Total assets	500,977				531,746				500,977	531,746	584,425
Capital expenditures									12,730	16,680	19,834
Depreciation and amortization									16,758	18,731	17,547
Operating Segments | Corrosion Protection
Segment Reporting Information [Line Items]
Total assets	279,106				329,848				279,106	329,848	424,007
Capital expenditures									9,754	8,603	14,393
Depreciation and amortization									11,874	15,598	18,792
Operating Segments | Energy Services
Segment Reporting Information [Line Items]
Total assets	163,109				152,416				163,109	152,416	147,171
Capital expenditures									3,053	2,713	2,514
Depreciation and amortization									7,111	6,726	7,067
Corporate, Non-Segment
Segment Reporting Information [Line Items]
Total assets	41,432				22,775				41,432	22,775	37,979
Capital expenditures									4,977	2,834	2,019
Depreciation and amortization									2,112	3,364	3,313
Reconciling Items | Held-for-sale assets
Segment Reporting Information [Line Items]
Total assets	$ 7,793				$ 70,314				7,793	70,314	0
Restructuring Plan 2016
Segment Reporting Information [Line Items]
Restructuring and related charges										0	(16,100)
Restructuring Plan 2016 | Infrastructure Solutions
Segment Reporting Information [Line Items]
Restructuring and related charges											(3,364)
Restructuring Plan 2016 | Corrosion Protection
Segment Reporting Information [Line Items]
Goodwill impairment											4,600
Restructuring and related charges											(4,565)
Restructuring Plan 2016 | Energy Services
Segment Reporting Information [Line Items]
Restructuring charges, net											8,200
Restructuring and related charges											(8,171)
Restructuring Plan 2016 | Corporate, Non-Segment
Segment Reporting Information [Line Items]
Restructuring and related charges											(1,400)
Bayou | Corrosion Protection | Held-for-sale assets
Segment Reporting Information [Line Items]
Acquisition and divestiture expenses									$ (6,200)
Bayou | Corrosion Protection | Discontinued Operations, Held-for-sale or Disposed of by Sale
Segment Reporting Information [Line Items]
Acquisition and divestiture expenses										(2,300)
Environmental Techniques | Infrastructure Solutions
Segment Reporting Information [Line Items]
Restructuring and related charges										$ (700)	$ (2,700)