Goodwill and Identified Intangible Assets - Intangible Assets (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 288,990	$ 285,752
Accumulated Amortization	(100,126)	(90,841)
Net Carrying Amount	$ 188,864	194,911
License agreements
Finite-Lived Intangible Assets [Line Items]
Weighted Average Useful Lives	9 years 11 months 4 days
Gross Carrying Amount	$ 4,467	4,418
Accumulated Amortization	(3,529)	(3,438)
Net Carrying Amount	$ 938	980
Leases
Finite-Lived Intangible Assets [Line Items]
Weighted Average Useful Lives	10 years 5 months 13 days
Gross Carrying Amount	$ 2,065	2,065
Accumulated Amortization	(985)	(912)
Net Carrying Amount	$ 1,080	1,153
Trademarks
Finite-Lived Intangible Assets [Line Items]
Weighted Average Useful Lives	13 years 5 months 13 days
Gross Carrying Amount	$ 24,435	24,185
Accumulated Amortization	(8,735)	(7,868)
Net Carrying Amount	15,700	16,317
Trademarks | Environmental Techniques
Finite-Lived Intangible Assets [Line Items]
Finite intangible assets acquired	$ 100
Non-competes
Finite-Lived Intangible Assets [Line Items]
Weighted Average Useful Lives	1 year 7 months 2 days
Gross Carrying Amount	$ 1,313	1,308
Accumulated Amortization	(1,111)	(1,054)
Net Carrying Amount	$ 202	254
Customer Relationships
Finite-Lived Intangible Assets [Line Items]
Weighted Average Useful Lives	10 years 11 months 25 days
Gross Carrying Amount	$ 189,787	187,554
Accumulated Amortization	(60,036)	(53,830)
Net Carrying Amount	129,751	133,724
Customer Relationships | Environmental Techniques
Finite-Lived Intangible Assets [Line Items]
Finite intangible assets acquired	$ 1,700
Patents and acquired technology
Finite-Lived Intangible Assets [Line Items]
Weighted Average Useful Lives	10 years 5 days
Gross Carrying Amount	$ 66,923	66,222
Accumulated Amortization	(25,730)	(23,739)
Net Carrying Amount	$ 41,193	$ 42,483