Financial Instruments and Fair Value Measurements - Transfer of Financial Assets Accounted for as Sales (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Mar. 31, 2023	Mar. 31, 2022	Mar. 31, 2023	Mar. 31, 2022	Sep. 30, 2022
Fair Value Disclosures [Abstract]
Trade receivables transferred to third parties under factoring arrangements	$ 750	$ 292	$ 1,490	$ 434
Amounts yet to be collected and remitted to the third parties	$ 359		$ 359		$ 323

Amount of derecognized financial assets from transactions which comprise an initial transfer and an agreement entered into in contemplation of the initial transfer resulting in retention of substantially all of the exposure to the economic return throughout the term of the transaction, at the date of derecognition.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 20
-Section 50
-Paragraph 4D
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=121570589&loc=SL51823488-111719

Name:	us-gaap_TransferOfFinancialAssetsAccountedForAsSalesAmountDerecognized
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant