Goodwill and Other Intangibles - Summary of Intangible Assets (Details) - USD ($) $ in Millions	Dec. 31, 2019	Sep. 30, 2019
Finite Lived Intangible Assets [Line Items]
Gross carrying amount	$ 1,533	$ 1,522
Accumulated amortization	(739)	(712)
Net carrying amount	794	810
Indefinite-Lived Intangible Assets (Excluding Goodwill) [Abstract]
Gross carrying amount	1,811	1,800
Net carrying amount	1,072	1,088
Trademarks and Trade Names [Member]
Finite Lived Intangible Assets [Line Items]
Gross carrying amount	66	66
Accumulated amortization	(30)	(29)
Net carrying amount	36	37
Indefinite-Lived Intangible Assets (Excluding Goodwill) [Abstract]
Indefinite-lived intangible assets	278	278
Intellectual Property [Member]
Finite Lived Intangible Assets [Line Items]
Gross carrying amount	717	712
Accumulated amortization	(405)	(391)
Net carrying amount	312	321
Customer and supplier relationships [Member]
Finite Lived Intangible Assets [Line Items]
Gross carrying amount	750	744
Accumulated amortization	(304)	(292)
Net carrying amount	$ 446	$ 452