Amount of damages awarded to the plaintiff in the legal matter.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 9
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121557415&loc=d3e14557-108349

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121557415&loc=d3e14435-108349

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=121557415&loc=d3e14326-108349

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

Litigation (Details) - Pending Litigation $ in Billions		1 Months Ended	12 Months Ended
Litigation (Details) - Pending Litigation $ in Billions	Nov. 13, 2013 USD ($)	Feb. 28, 2011 USD ($)	Dec. 31, 1991	Sep. 30, 2020 legal_matter	Jan. 31, 2012
MTBE
Loss Contingencies [Line Items]
Pending lawsuits and claims (in number of claims) \| legal_matter				6
Ecuador
Loss Contingencies [Line Items]
Conducted remediation program			3 years
Amount assessed in damages \| $	$ 9.5	$ 9.5
Proposed additional payment for plaintiff attorney fees as percentage of judgment					0.10%