Restructuring (Details) (USD $)	1 Months Ended		3 Months Ended	12 Months Ended
	Dec. 31, 2014	Feb. 28, 2015	Mar. 31, 2015 position	Dec. 31, 2014 position
Ka-te [Member]
Restructuring Cost and Reserve [Line Items]
Period of trademark license	5 years
Video Injection - Instituform SAS [Member]
Restructuring Cost and Reserve [Line Items]
Period of trademark license		5 years
Insituform Linings Ltd. [Member] | Ka-te [Member]
Restructuring Cost and Reserve [Line Items]
Term of exclusive tube supply agreement	5 years
Insituform Linings Ltd. [Member] | Video Injection - Instituform SAS [Member]
Restructuring Cost and Reserve [Line Items]
Term of exclusive tube supply agreement		5 years
Restructuring Plan 2014 [Member]
Restructuring Cost and Reserve [Line Items]
Number of terminations			13	31
Expected terminations in 2015			65
Total pre-tax restructuring charges to date			$ 53,100,000
Total restructuring charges to date, net of tax			39,400,000
Restructuring Plan 2014 [Member] | Infrastructure Solutions [Member]
Restructuring Cost and Reserve [Line Items]
Pre-tax charges related to restructuring			3,538,000
Charges related to restructuring, post-tax			3,300,000
Restructuring Plan 2014 [Member] | Severance, other termination benefit costs, and early lease termination costs [Member]
Restructuring Cost and Reserve [Line Items]
Pre-tax charges related to restructuring			700,000
Restructuring Plan 2014 [Member] | Non-cash restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Total pre-tax restructuring charges to date			45,400,000
Restructuring Plan 2014 [Member] | Non-cash restructuring [Member] | Corrosion Protection [Member]
Restructuring Cost and Reserve [Line Items]
Total pre-tax restructuring charges to date			22,200,000
Restructuring Plan 2014 [Member] | Non-cash restructuring [Member] | Infrastructure Solutions [Member]
Restructuring Cost and Reserve [Line Items]
Total pre-tax restructuring charges to date			23,200,000
Restructuring Plan 2014 [Member] | Cash restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Total pre-tax restructuring charges to date			7,700,000
Restructuring Plan 2014 [Member] | Severance and benefit costs [Member] | Infrastructure Solutions [Member]
Restructuring Cost and Reserve [Line Items]
Pre-tax charges related to restructuring			516,000
Restructuring Plan 2014 [Member] | Severance and benefit costs [Member] | Minimum [Member]
Restructuring Cost and Reserve [Line Items]
Estimated remaining restructuring costs to be incurred in 2015			1,000,000
Restructuring Plan 2014 [Member] | Severance and benefit costs [Member] | Maximum [Member]
Restructuring Cost and Reserve [Line Items]
Estimated remaining restructuring costs to be incurred in 2015			2,000,000
Restructuring Plan 2014 [Member] | Other restructuring costs [Member] | Infrastructure Solutions [Member]
Restructuring Cost and Reserve [Line Items]
Pre-tax charges related to restructuring			3,471,000
Restructuring Plan 2014 [Member] | Other restructuring costs [Member] | Minimum [Member]
Restructuring Cost and Reserve [Line Items]
Estimated remaining restructuring costs to be incurred in 2015			3,000,000
Restructuring Plan 2014 [Member] | Other restructuring costs [Member] | Maximum [Member]
Restructuring Cost and Reserve [Line Items]
Estimated remaining restructuring costs to be incurred in 2015			$ 4,000,000