Restructuring - Pre Tax Restructuring Cost (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 1,086	$ 1,789
Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	2,866	5,244
Severance and benefit related costs | Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	495	1,071
Lease and contract termination costs | Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	540	678
Relocation and other moving costs | Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	51	40
Other restructuring | Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	1,780	3,455
Operating Segments | Infrastructure Solutions | Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	2,502	3,216
Operating Segments | Infrastructure Solutions | Severance and benefit related costs | Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	282	780
Operating Segments | Infrastructure Solutions | Lease and contract termination costs | Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	425	528
Operating Segments | Infrastructure Solutions | Relocation and other moving costs | Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	51	40
Operating Segments | Infrastructure Solutions | Other restructuring | Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	1,744	1,868
Operating Segments | Corrosion Protection | Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	(24)	1,465
Operating Segments | Corrosion Protection | Severance and benefit related costs | Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	170	121
Operating Segments | Corrosion Protection | Lease and contract termination costs | Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	17	0
Operating Segments | Corrosion Protection | Relocation and other moving costs | Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	0	0
Operating Segments | Corrosion Protection | Other restructuring | Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	(211)	1,344
Operating Segments | Energy Services | Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	34	0
Operating Segments | Energy Services | Severance and benefit related costs | Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	34	0
Operating Segments | Energy Services | Lease and contract termination costs | Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	0	0
Operating Segments | Energy Services | Relocation and other moving costs | Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	0	0
Operating Segments | Energy Services | Other restructuring | Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	0	0
Corporate | Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	354	563
Corporate | Severance and benefit related costs | Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	9	170
Corporate | Lease and contract termination costs | Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	98	150
Corporate | Relocation and other moving costs | Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	0	0
Corporate | Other restructuring | Restructuring 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 247	$ 243