Restructuring - Restructuring Reserve by Type of Cost (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		21 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016
Restructuring Plan 2016
Restructuring Cost and Reserve [Line Items]
Non-Cash Restructuring Charges (Reversals)	$ 508		$ 508
Cash Restructuring Charges (Reversals)	3,255		12,997
Pre-tax charges (reversals) related to restructuring	3,763		13,505
Restructuring Plan 2016 | Cost of revenues
Restructuring Cost and Reserve [Line Items]
Non-Cash Restructuring Charges (Reversals)	0		0
Cash Restructuring Charges (Reversals)	10		59
Pre-tax charges (reversals) related to restructuring	10		59
Restructuring Plan 2016 | Operating expenses
Restructuring Cost and Reserve [Line Items]
Non-Cash Restructuring Charges (Reversals)	259		259
Cash Restructuring Charges (Reversals)	1,710		4,673
Pre-tax charges (reversals) related to restructuring	1,969		4,932
Restructuring Plan 2016 | Restructuring Charges
Restructuring Cost and Reserve [Line Items]
Non-Cash Restructuring Charges (Reversals)	0		0
Cash Restructuring Charges (Reversals)	1,535		8,265
Pre-tax charges (reversals) related to restructuring	1,535		8,265
Restructuring Plan 2016 | Other expense
Restructuring Cost and Reserve [Line Items]
Non-Cash Restructuring Charges (Reversals)	249		249
Cash Restructuring Charges (Reversals)	0		0
Pre-tax charges (reversals) related to restructuring	249		249
Restructuring Plan 2014
Restructuring Cost and Reserve [Line Items]
Non-Cash Restructuring Charges (Reversals)	(20)	$ 2,571	(232)	$ 4,076
Cash Restructuring Charges (Reversals)	80	3,123	112	5,156
Pre-tax charges (reversals) related to restructuring	60	5,694	(120)	9,232	$ 60,400
Restructuring Plan 2014 | Cost of revenues
Restructuring Cost and Reserve [Line Items]
Non-Cash Restructuring Charges (Reversals)	0	35	0	(132)
Cash Restructuring Charges (Reversals)	0	933	(14)	1,114
Pre-tax charges (reversals) related to restructuring	0	968	(14)	982
Restructuring Plan 2014 | Operating expenses
Restructuring Cost and Reserve [Line Items]
Non-Cash Restructuring Charges (Reversals)	(20)	2,290	(361)	1,270
Cash Restructuring Charges (Reversals)	80	2,210	59	3,362
Pre-tax charges (reversals) related to restructuring	60	4,500	(302)	4,632
Restructuring Plan 2014 | Restructuring Charges
Restructuring Cost and Reserve [Line Items]
Non-Cash Restructuring Charges (Reversals)	0	0	0	0
Cash Restructuring Charges (Reversals)	0	204	67	862
Pre-tax charges (reversals) related to restructuring	0	204	67	862
Restructuring Plan 2014 | Other expense
Restructuring Cost and Reserve [Line Items]
Non-Cash Restructuring Charges (Reversals)	0	246	129	2,938
Cash Restructuring Charges (Reversals)	0	(224)	0	(182)
Pre-tax charges (reversals) related to restructuring	0	$ 22	129	$ 2,756
Infrastructure Solutions | Restructuring Plan 2016 | Operating expenses
Restructuring Cost and Reserve [Line Items]
Pre-tax charges (reversals) related to restructuring	400		600
Infrastructure Solutions | Restructuring Plan 2016 | Restructuring Charges
Restructuring Cost and Reserve [Line Items]
Pre-tax charges (reversals) related to restructuring	600		2,500
Corrosion Protection | Restructuring Plan 2016 | Operating expenses
Restructuring Cost and Reserve [Line Items]
Pre-tax charges (reversals) related to restructuring	100		400
Corrosion Protection | Restructuring Plan 2016 | Restructuring Charges
Restructuring Cost and Reserve [Line Items]
Pre-tax charges (reversals) related to restructuring	800		3,200
Energy Services | Restructuring Plan 2016 | Operating expenses
Restructuring Cost and Reserve [Line Items]
Pre-tax charges (reversals) related to restructuring	1,500		3,900
Energy Services | Restructuring Plan 2016 | Restructuring Charges
Restructuring Cost and Reserve [Line Items]
Pre-tax charges (reversals) related to restructuring	$ 100		$ 2,500