Restructuring - Restructuring Reserve by Type of Cost (Details) - Restructuring Plan 2016 - USD ($)	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Restructuring Cost and Reserve [Line Items]
Pre-tax charges (reversals) related to restructuring	$ 0	$ 9,742,000
Cost of revenues
Restructuring Cost and Reserve [Line Items]
Pre-tax charges (reversals) related to restructuring		49,000
Operating expenses
Restructuring Cost and Reserve [Line Items]
Pre-tax charges (reversals) related to restructuring		2,963,000
Restructuring charges
Restructuring Cost and Reserve [Line Items]
Pre-tax charges (reversals) related to restructuring		6,730,000
Infrastructure Solutions | Operating expenses
Restructuring Cost and Reserve [Line Items]
Pre-tax charges (reversals) related to restructuring		200,000
Infrastructure Solutions | Restructuring charges
Restructuring Cost and Reserve [Line Items]
Pre-tax charges (reversals) related to restructuring		1,900,000
Corrosion Protection | Operating expenses
Restructuring Cost and Reserve [Line Items]
Pre-tax charges (reversals) related to restructuring		300,000
Corrosion Protection | Restructuring charges
Restructuring Cost and Reserve [Line Items]
Pre-tax charges (reversals) related to restructuring		2,400,000
Energy Services | Operating expenses
Restructuring Cost and Reserve [Line Items]
Pre-tax charges (reversals) related to restructuring		2,500,000
Energy Services | Restructuring charges
Restructuring Cost and Reserve [Line Items]
Pre-tax charges (reversals) related to restructuring		$ 2,400,000