Reflects the estimated amount of loss from the specified contingency as of the balance sheet date.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121557415&loc=d3e14435-108349

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 9
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121557415&loc=d3e14557-108349

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 460
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=121555522&loc=d3e12021-110248

Name:	us-gaap_LossContingencyEstimateOfPossibleLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Commitments and Contingent Liabilities (Details) - USD ($) $ in Millions	Sep. 30, 2020	Sep. 30, 2017
PRP site
Commitments And Contingent Liabilities [Line Items]
Estimated future remediation costs	$ 8
Non- PRP sites
Commitments And Contingent Liabilities [Line Items]
Estimated future remediation costs	7
Penalty Notification Alleging Misclassification of Importation of Certain Goods into U.S. During 2004-2009 \| U.S. Customs and Border Protection (CBP)
Commitments And Contingent Liabilities [Line Items]
Assessed penalty	$ 6	$ 18