Goodwill Rollforward (Details) $ in Thousands	9 Months Ended
Sep. 30, 2017 USD ($)
Goodwill [Line Items]
Goodwill, Beginning	$ 345,269
Addition due to acquisition	8,007
Foreign currency translation	2,579
Goodwill, Ending	355,855
Specialty Chemicals and Electronic Materials SCEM [Member]
Goodwill [Line Items]
Goodwill, Beginning	297,858
Addition due to acquisition	0
Foreign currency translation	2,579
Goodwill, Ending	300,437
Microcontamination Control MC [Member]
Goodwill [Line Items]
Goodwill, Beginning	0
Addition due to acquisition	8,007
Foreign currency translation	0
Goodwill, Ending	8,007
Advanced Materials Handling AMH [Member]
Goodwill [Line Items]
Goodwill, Beginning	47,411
Addition due to acquisition	0
Foreign currency translation	0
Goodwill, Ending	$ 47,411

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6388280&loc=d3e13770-109266

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=77989000&loc=SL49117168-202975

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Amount of increase in asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized resulting from a business combination.

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Amount of foreign currency translation gain (loss) which increases (decreases) an asset representing future economic benefits from other assets acquired in a business combination that are not individually identified and separately recognized.

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