Restructuring - Restructuring Costs by Segment (Details) - USD ($)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Restructuring Cost and Reserve [Line Items]
Pre-tax charges related to restructuring	$ 0	$ 1,535,000	$ 0	$ 8,332,000
Restructuring Plan 2016
Restructuring Cost and Reserve [Line Items]
Pre-tax charges related to restructuring		3,763,000	$ 0	13,505,000	$ 16,100,000
Restructuring Plan 2016 | Corporate, Non-Segment
Restructuring Cost and Reserve [Line Items]
Pre-tax charges related to restructuring		200,000		1,200,000
Restructuring Plan 2016 | Severance and benefit related costs
Restructuring Cost and Reserve [Line Items]
Pre-tax charges related to restructuring		1,152,000		6,793,000
Restructuring Plan 2016 | Lease termination costs
Restructuring Cost and Reserve [Line Items]
Pre-tax charges related to restructuring				969,000
Restructuring Plan 2016 | Relocation and other moving costs
Restructuring Cost and Reserve [Line Items]
Pre-tax charges related to restructuring		383,000		503,000
Restructuring Plan 2016 | Other restructuring costs
Restructuring Cost and Reserve [Line Items]
Pre-tax charges related to restructuring		2,228,000		5,240,000
Restructuring Plan 2016 | Infrastructure Solutions
Restructuring Cost and Reserve [Line Items]
Pre-tax charges related to restructuring		1,219,000		3,372,000
Restructuring Plan 2016 | Infrastructure Solutions | Severance and benefit related costs
Restructuring Cost and Reserve [Line Items]
Pre-tax charges related to restructuring		344,000		2,256,000
Restructuring Plan 2016 | Infrastructure Solutions | Lease termination costs
Restructuring Cost and Reserve [Line Items]
Pre-tax charges related to restructuring				0
Restructuring Plan 2016 | Infrastructure Solutions | Relocation and other moving costs
Restructuring Cost and Reserve [Line Items]
Pre-tax charges related to restructuring		307,000		307,000
Restructuring Plan 2016 | Infrastructure Solutions | Other restructuring costs
Restructuring Cost and Reserve [Line Items]
Pre-tax charges related to restructuring		568,000		809,000
Restructuring Plan 2016 | Corrosion Protection
Restructuring Cost and Reserve [Line Items]
Pre-tax charges related to restructuring		957,000		3,694,000
Restructuring Plan 2016 | Corrosion Protection | Severance and benefit related costs
Restructuring Cost and Reserve [Line Items]
Pre-tax charges related to restructuring		714,000		3,134,000
Restructuring Plan 2016 | Corrosion Protection | Lease termination costs
Restructuring Cost and Reserve [Line Items]
Pre-tax charges related to restructuring				0
Restructuring Plan 2016 | Corrosion Protection | Relocation and other moving costs
Restructuring Cost and Reserve [Line Items]
Pre-tax charges related to restructuring		62,000		62,000
Restructuring Plan 2016 | Corrosion Protection | Other restructuring costs
Restructuring Cost and Reserve [Line Items]
Pre-tax charges related to restructuring		181,000		498,000
Restructuring Plan 2016 | Energy Services
Restructuring Cost and Reserve [Line Items]
Pre-tax charges related to restructuring		1,587,000		6,439,000
Restructuring Plan 2016 | Energy Services | Severance and benefit related costs
Restructuring Cost and Reserve [Line Items]
Pre-tax charges related to restructuring		94,000		1,403,000
Restructuring Plan 2016 | Energy Services | Lease termination costs
Restructuring Cost and Reserve [Line Items]
Pre-tax charges related to restructuring				969,000
Restructuring Plan 2016 | Energy Services | Relocation and other moving costs
Restructuring Cost and Reserve [Line Items]
Pre-tax charges related to restructuring		14,000		134,000
Restructuring Plan 2016 | Energy Services | Other restructuring costs
Restructuring Cost and Reserve [Line Items]
Pre-tax charges related to restructuring		$ 1,479,000		$ 3,933,000