Goodwill (Details) $ in Thousands	3 Months Ended
Mar. 31, 2020 USD ($)
Goodwill
Beginning balance	$ 1,259,805
Goodwill recognized	5,764
Foreign exchange impact	(16,835)
Ending balance	1,248,734
Refining Services
Goodwill
Beginning balance	311,892
Goodwill recognized	0
Foreign exchange impact	0
Ending balance	311,892
Catalysts
Goodwill
Beginning balance	78,611
Goodwill recognized	0
Foreign exchange impact	(1,438)
Ending balance	77,173
Performance Materials
Goodwill
Beginning balance	275,919
Goodwill recognized	5,764
Foreign exchange impact	(1,745)
Ending balance	279,938
Performance Chemicals
Goodwill
Beginning balance	593,383
Goodwill recognized	0
Foreign exchange impact	(13,652)
Ending balance	$ 579,731

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://fasb.org/us-gaap/role/ref/legacyRef
-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

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=99380562&loc=d3e13770-109266

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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.

+ References

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 (b)
-URI http://asc.fasb.org/extlink&oid=108376223&loc=d3e13816-109267

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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.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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