Restructuring - 2017 Restructuring (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended			17 Months Ended
	Sep. 30, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2018
Restructuring Cost and Reserve [Line Items]
Restructuring and related charges		$ 6,894	$ 12,814	$ 9,168
Goodwill impairment		1,389	45,390	0
Definite-lived intangible asset impairment		2,169	41,032	0
Restructuring Plan 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges, incurred		29,486	23,743
Restructuring and related charges		29,486	23,743
Definite-lived intangible asset impairment					$ 86,400
Restructuring charges, cash		12,100	13,600
Restructuring charges, non-cash		17,400	10,100
Cash		14,800	8,474		25,800
Utilized non-cash		17,372	10,080		113,900
Restructuring reserve		2,412	5,189		2,412
Restructuring Plan 2017 | Cost of revenues
Restructuring Cost and Reserve [Line Items]
Restructuring charges, incurred		1,881	45
Restructuring Plan 2017 | Operating expenses
Restructuring Cost and Reserve [Line Items]
Restructuring charges, incurred		13,319	10,884
Goodwill impairment		1,389
Definite-lived intangible asset impairment		2,034
Restructuring Plan 2017 | Restructuring charges
Restructuring Cost and Reserve [Line Items]
Restructuring charges, incurred		6,894	12,814
Restructuring Plan 2017 | Other expense
Restructuring Cost and Reserve [Line Items]
Restructuring charges, incurred		3,969
Severance and benefit related costs | Restructuring Plan 2017
Restructuring Cost and Reserve [Line Items]
Restructuring and related charges		4,536	7,345
Cash		6,589	3,481
Utilized non-cash		0	0
Restructuring reserve		1,742	3,864		1,742
Lease termination costs | Restructuring Plan 2017
Restructuring Cost and Reserve [Line Items]
Restructuring and related charges		2,174	5,320
Cash		2,446	2,706
Utilized non-cash		0	1,964
Restructuring reserve		359	650		359
Relocation and other moving costs | Restructuring Plan 2017
Restructuring Cost and Reserve [Line Items]
Restructuring and related charges		184	147
Cash		184	147
Utilized non-cash		0	0
Restructuring reserve		0	0		0
Other restructuring | Restructuring Plan 2017
Restructuring Cost and Reserve [Line Items]
Restructuring and related charges		22,592	10,931
Cash		5,581	2,140
Utilized non-cash		17,372	8,116
Restructuring reserve		311	675		$ 311
Infrastructure Solutions
Restructuring Cost and Reserve [Line Items]
Restructuring and related charges				$ 2,900
Goodwill impairment	$ 45,400	1,389	45,390
Infrastructure Solutions | Restructuring Plan 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges, incurred		19,343	17,826
Restructuring and related charges		19,343	17,826
Infrastructure Solutions | Restructuring Plan 2017 | Cost of revenues
Restructuring Cost and Reserve [Line Items]
Restructuring charges, incurred		1,282	30
Infrastructure Solutions | Restructuring Plan 2017 | Operating expenses
Restructuring Cost and Reserve [Line Items]
Restructuring charges, incurred		7,976	8,636
Goodwill impairment		1,389
Definite-lived intangible asset impairment		910
Infrastructure Solutions | Restructuring Plan 2017 | Restructuring charges
Restructuring Cost and Reserve [Line Items]
Restructuring charges, incurred		5,306	9,160
Infrastructure Solutions | Restructuring Plan 2017 | Other expense
Restructuring Cost and Reserve [Line Items]
Restructuring charges, incurred		2,480
Infrastructure Solutions | Severance and benefit related costs | Restructuring Plan 2017
Restructuring Cost and Reserve [Line Items]
Restructuring and related charges		3,124	4,587
Infrastructure Solutions | Lease termination costs | Restructuring Plan 2017
Restructuring Cost and Reserve [Line Items]
Restructuring and related charges		1,999	4,545
Infrastructure Solutions | Relocation and other moving costs | Restructuring Plan 2017
Restructuring Cost and Reserve [Line Items]
Restructuring and related charges		184	26
Infrastructure Solutions | Other restructuring | Restructuring Plan 2017
Restructuring Cost and Reserve [Line Items]
Restructuring and related charges		14,036	8,668
Corrosion Protection
Restructuring Cost and Reserve [Line Items]
Goodwill impairment		0	0
Corrosion Protection | Restructuring Plan 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges, incurred		9,753	5,917
Restructuring and related charges		9,753	5,917
Corrosion Protection | Restructuring Plan 2017 | Cost of revenues
Restructuring Cost and Reserve [Line Items]
Restructuring charges, incurred		599	15
Corrosion Protection | Restructuring Plan 2017 | Operating expenses
Restructuring Cost and Reserve [Line Items]
Restructuring charges, incurred		5,187	2,248
Goodwill impairment		0
Definite-lived intangible asset impairment		1,124
Corrosion Protection | Restructuring Plan 2017 | Restructuring charges
Restructuring Cost and Reserve [Line Items]
Restructuring charges, incurred		1,354	3,654
Corrosion Protection | Restructuring Plan 2017 | Other expense
Restructuring Cost and Reserve [Line Items]
Restructuring charges, incurred		1,489
Corrosion Protection | Severance and benefit related costs | Restructuring Plan 2017
Restructuring Cost and Reserve [Line Items]
Restructuring and related charges		1,178	2,758
Corrosion Protection | Lease termination costs | Restructuring Plan 2017
Restructuring Cost and Reserve [Line Items]
Restructuring and related charges		175	775
Corrosion Protection | Relocation and other moving costs | Restructuring Plan 2017
Restructuring Cost and Reserve [Line Items]
Restructuring and related charges		0	121
Corrosion Protection | Other restructuring | Restructuring Plan 2017
Restructuring Cost and Reserve [Line Items]
Restructuring and related charges		8,400	2,263
Energy Services
Restructuring Cost and Reserve [Line Items]
Goodwill impairment		0	0
Energy Services | Restructuring Plan 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges, incurred		390
Restructuring and related charges		390
Energy Services | Restructuring Plan 2017 | Cost of revenues
Restructuring Cost and Reserve [Line Items]
Restructuring charges, incurred		0
Energy Services | Restructuring Plan 2017 | Operating expenses
Restructuring Cost and Reserve [Line Items]
Restructuring charges, incurred		156
Goodwill impairment		0
Definite-lived intangible asset impairment		0
Energy Services | Restructuring Plan 2017 | Restructuring charges
Restructuring Cost and Reserve [Line Items]
Restructuring charges, incurred		234
Energy Services | Restructuring Plan 2017 | Other expense
Restructuring Cost and Reserve [Line Items]
Restructuring charges, incurred		0
Energy Services | Severance and benefit related costs | Restructuring Plan 2017
Restructuring Cost and Reserve [Line Items]
Restructuring and related charges		234
Energy Services | Lease termination costs | Restructuring Plan 2017
Restructuring Cost and Reserve [Line Items]
Restructuring and related charges		0
Energy Services | Relocation and other moving costs | Restructuring Plan 2017
Restructuring Cost and Reserve [Line Items]
Restructuring and related charges		0
Energy Services | Other restructuring | Restructuring Plan 2017
Restructuring Cost and Reserve [Line Items]
Restructuring and related charges		156
Corporate, Non-Segment | Restructuring Plan 2017
Restructuring Cost and Reserve [Line Items]
Restructuring and related charges		$ 1,600	$ 1,300