Segment and Geographic Information - Financial Information by Segment (Details) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017 USD ($)	Sep. 30, 2017 USD ($)	Jun. 30, 2017 USD ($)	Mar. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Sep. 30, 2016 USD ($)	Jun. 30, 2016 USD ($)	Mar. 31, 2016 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($) lawsuit	Dec. 31, 2015 USD ($)
Segment Reporting Information [Line Items]
Revenues	$ 337,499	$ 341,872	$ 354,473	$ 325,175	$ 321,802	$ 308,524	$ 297,686	$ 293,908	$ 1,359,019	$ 1,221,920	$ 1,333,570
Operating income (loss)	(3,956)	(75,009)	$ 21,659	$ 14,133	26,315	$ 20,505	$ 8,145	$ (4,139)	(43,173)	50,826	19,946
Interest expense									(16,001)	(15,029)	(16,044)
Interest income									145	166	218
Other									(2,201)	(694)	(2,905)
Total other expense									(18,057)	(15,557)	(18,731)
Income (loss) before taxes on income									(61,230)	35,269	1,215
Total assets	1,107,099				1,193,582				1,107,099	1,193,582	1,254,013
Capital expenditures									30,830	38,760	29,454
Depreciation and amortization									45,374	46,719	43,791
Acquisition and divestiture expenses									(2,923)	(2,696)	(1,912)
Gain on litigation settlement									0	6,625	0
Goodwill impairment									45,390	0	43,484
Restructuring and related charges									12,814	9,168	968
Infrastructure Solutions
Segment Reporting Information [Line Items]
Revenues									612,154	571,551	556,234
Operating income (loss)									(61,807)	53,503	46,867
Restructuring charges, net									(18,100)	(2,900)
Inventory step up expense										3,600
Gain on litigation settlement										$ 6,600
Number of lawsuits settled | lawsuit										2
Goodwill impairment		$ 45,400							45,390
Impairment of intangible assets									41,000
Acquisition-related expenses									700		1,100
Corrosion Protection
Segment Reporting Information [Line Items]
Revenues									456,139	$ 401,469	437,921
Operating income (loss)									12,437	1,809	(1,771)
Restructuring charges, net									(5,900)
Goodwill impairment									0		10,000
Acquisition-related expenses											500
Energy Services
Segment Reporting Information [Line Items]
Revenues									290,726	248,900	339,415
Operating income (loss)									6,197	(4,486)	(25,150)
Restructuring charges, net										(8,200)
Goodwill impairment									0		33,500
Acquisition-related expenses											300
Operating Segments | Infrastructure Solutions
Segment Reporting Information [Line Items]
Total assets	531,746				584,425				531,746	584,425	508,817
Capital expenditures									16,680	19,834	7,657
Depreciation and amortization									18,731	17,547	14,836
Operating Segments | Corrosion Protection
Segment Reporting Information [Line Items]
Total assets	329,848				424,007				329,848	424,007	489,519
Capital expenditures									8,603	14,393	17,226
Depreciation and amortization									15,598	18,792	18,834
Operating Segments | Energy Services
Segment Reporting Information [Line Items]
Total assets	152,416				147,171				152,416	147,171	183,763
Capital expenditures									2,713	2,514	2,202
Depreciation and amortization									6,726	7,067	7,641
Corporate, Non-Segment
Segment Reporting Information [Line Items]
Total assets	22,775				37,979				22,775	37,979	50,854
Capital expenditures									2,834	2,019	2,369
Depreciation and amortization									4,319	3,313	2,480
Reconciling Items | Held-for-sale assets
Segment Reporting Information [Line Items]
Total assets	$ 70,314				$ 0				70,314	0	21,060
Restructuring Plan 2016
Segment Reporting Information [Line Items]
Restructuring and related charges										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]
Restructuring charges, net										(4,600)
Restructuring and related charges										4,565
Restructuring Plan 2016 | Energy Services
Segment Reporting Information [Line Items]
Restructuring and related charges										8,171
Restructuring Plan 2016 | Corporate, Non-Segment
Segment Reporting Information [Line Items]
Restructuring and related charges										$ 1,400
Restructuring Plan 2014 | Infrastructure Solutions
Segment Reporting Information [Line Items]
Restructuring and related charges											$ 8,100
Bayou | Corrosion Protection | Held-for-sale assets
Segment Reporting Information [Line Items]
Acquisition and divestiture expenses									$ (2,300)