Amount of increase (decrease), classified as other, of an asset representing the future economic benefits from other assets acquired in a business combination that are not individually identified and separately recognized.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (g)
-URI http://asc.fasb.org/extlink&oid=108376223&loc=d3e13816-109267

Name:	us-gaap_GoodwillOtherIncreaseDecrease
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Goodwill and Other Intangible Assets - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019
Goodwill [Line Items]
Additions (reductions) in goodwill		$ (65)
Performance Materials
Goodwill [Line Items]
Additions (reductions) in goodwill		(65)
Interface Performance Materials
Goodwill [Line Items]
Additions (reductions) in goodwill		$ (700)
Hollingsworth & Vose Company
Goodwill [Line Items]
Additions (reductions) in goodwill	$ 600