Goodwill and Identified Intangible Assets - Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 288,406	$ 285,752
Accumulated Amortization	(95,304)	(90,841)
Net Carrying Amount	$ 193,102	194,911
License agreements
Finite-Lived Intangible Assets [Line Items]
Weighted Average Useful Lives	9 years 3 months 9 days
Gross Carrying Amount	$ 4,426	4,418
Accumulated Amortization	(3,488)	(3,438)
Net Carrying Amount	$ 938	980
Leases
Finite-Lived Intangible Assets [Line Items]
Weighted Average Useful Lives	10 years 7 months 5 days
Gross Carrying Amount	$ 2,065	2,065
Accumulated Amortization	(948)	(912)
Net Carrying Amount	$ 1,117	1,153
Trademarks
Finite-Lived Intangible Assets [Line Items]
Weighted Average Useful Lives	13 years 8 months 15 days
Gross Carrying Amount	$ 24,664	24,185
Accumulated Amortization	(8,285)	(7,868)
Net Carrying Amount	16,379	16,317
Trademarks | Environmental Techniques
Finite-Lived Intangible Assets [Line Items]
Finite intangible assets acquired	$ 400
Non-competes
Finite-Lived Intangible Assets [Line Items]
Weighted Average Useful Lives	1 year 7 months 13 days
Gross Carrying Amount	$ 1,309	1,308
Accumulated Amortization	(1,082)	(1,054)
Net Carrying Amount	$ 227	254
Customer Relationships
Finite-Lived Intangible Assets [Line Items]
Weighted Average Useful Lives	11 years 2 months 15 days
Gross Carrying Amount	$ 189,416	187,554
Accumulated Amortization	(56,898)	(53,830)
Net Carrying Amount	132,518	133,724
Customer Relationships | Environmental Techniques
Finite-Lived Intangible Assets [Line Items]
Finite intangible assets acquired	$ 1,600
Patents and acquired technology
Finite-Lived Intangible Assets [Line Items]
Weighted Average Useful Lives	10 years
Gross Carrying Amount	$ 66,526	66,222
Accumulated Amortization	(24,603)	(23,739)
Net Carrying Amount	$ 41,923	$ 42,483