Restructuring - Recognized Cost Restructuring Activities (Details) - Restructuring 2017 - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	$ 2,866	$ 5,244
Restructuring charges, cash	3,100	2,800
Restructuring charges, non-cash	(200)	2,400
Cost of revenues
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	74
Operating expenses
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	1,530	3,455
Restructuring and related charges
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	1,086	1,789
Other expense
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	176
Operating Segments | Infrastructure Solutions
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	2,502	3,216
Operating Segments | Infrastructure Solutions | Cost of revenues
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	(25)
Operating Segments | Infrastructure Solutions | Operating expenses
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	1,346	1,868
Operating Segments | Infrastructure Solutions | Restructuring and related charges
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	758	1,348
Operating Segments | Infrastructure Solutions | Other expense
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	423
Operating Segments | Corrosion Protection
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	(24)	1,465
Operating Segments | Corrosion Protection | Cost of revenues
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	99
Operating Segments | Corrosion Protection | Operating expenses
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	(63)	1,344
Operating Segments | Corrosion Protection | Restructuring and related charges
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	187	121
Operating Segments | Corrosion Protection | Other expense
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	(247)
Operating Segments | Energy Services
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	34	0
Operating Segments | Energy Services | Cost of revenues
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	0
Operating Segments | Energy Services | Operating expenses
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	0	0
Operating Segments | Energy Services | Restructuring and related charges
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	34	0
Operating Segments | Energy Services | Other expense
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	0
Corporate
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	354	563
Corporate | Cost of revenues
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	0
Corporate | Operating expenses
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	247	243
Corporate | Restructuring and related charges
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	107	$ 320
Corporate | Other expense
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	$ 0