Restructuring - Recognized Cost Restructuring Activities (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2016
Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	$ 6,737
Restructuring charges, cash	6,600
Restructuring charges, non-cash	77
Restructuring 2017 | Cost of revenues
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	45
Restructuring 2017 | Operating expenses
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	1,253
Restructuring 2017 | Restructuring and related charges
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	5,439
Restructuring 2016
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost		$ 1,287	$ 14,791
Restructuring charges, cash		1,030	14,026
Restructuring charges, non-cash		257	765
Restructuring 2016 | Cost of revenues
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost		130	189
Restructuring 2016 | Operating expenses
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost		945	5,876
Restructuring 2016 | Restructuring and related charges
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost		212	8,477
Restructuring 2016 | Other expense
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost		0	249
Infrastructure Solutions | Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	4,573
Infrastructure Solutions | Restructuring 2017 | Cost of revenues
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	30
Infrastructure Solutions | Restructuring 2017 | Operating expenses
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	1,153
Infrastructure Solutions | Restructuring 2017 | Restructuring and related charges
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	3,390
Infrastructure Solutions | Restructuring 2016
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost		(31)	3,340
Infrastructure Solutions | Restructuring 2016 | Cost of revenues
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost		0	0
Infrastructure Solutions | Restructuring 2016 | Operating expenses
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost		(31)	528
Infrastructure Solutions | Restructuring 2016 | Restructuring and related charges
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost			2,563
Infrastructure Solutions | Restructuring 2016 | Other expense
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost		0	249
Corrosion Protection | Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	2,164
Corrosion Protection | Restructuring 2017 | Cost of revenues
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	15
Corrosion Protection | Restructuring 2017 | Operating expenses
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	100
Corrosion Protection | Restructuring 2017 | Restructuring and related charges
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	$ 2,049
Corrosion Protection | Restructuring 2016
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost		178	3,872
Corrosion Protection | Restructuring 2016 | Cost of revenues
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost		130	189
Corrosion Protection | Restructuring 2016 | Operating expenses
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost		0	439
Corrosion Protection | Restructuring 2016 | Restructuring and related charges
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost		48	3,244
Corrosion Protection | Restructuring 2016 | Other expense
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost		0	0
Energy Services | Restructuring 2016
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost		1,140	7,579
Energy Services | Restructuring 2016 | Cost of revenues
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost		0	0
Energy Services | Restructuring 2016 | Operating expenses
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost		976	4,909
Energy Services | Restructuring 2016 | Restructuring and related charges
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost		164	2,670
Energy Services | Restructuring 2016 | Other expense
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost		$ 0	$ 0