Goodwill and Other Intangible Assets - Other Intangible Assets (Details) - USD ($) $ in Millions	Dec. 31, 2019	Sep. 30, 2019
Intangible Assets [Line Items]
Gross carrying amount, total intangible assets	$ 7,061	$ 6,985
Net, Total Intangible Assets	5,610	5,632
Finite-Lived Intangible Assets, Gross [Abstract]
Gross Carrying Amount	4,667	4,613
Accumulated Amortization	(1,451)	(1,353)
Net, Total Amortized Intangible Assets	3,216	3,260
Indefinite-lived Intangible Assets (Excluding Goodwill) [Abstract]
Carrying Amount, Gross and Net	2,394	2,372
Patented Technology
Finite-Lived Intangible Assets, Gross [Abstract]
Gross Carrying Amount	1,328	1,307
Accumulated Amortization	(403)	(370)
Net, Total Amortized Intangible Assets	925	937
Customer Relationships
Finite-Lived Intangible Assets, Gross [Abstract]
Gross Carrying Amount	2,754	2,722
Accumulated Amortization	(817)	(759)
Net, Total Amortized Intangible Assets	1,937	1,963
Miscellaneous
Finite-Lived Intangible Assets, Gross [Abstract]
Gross Carrying Amount	585	584
Accumulated Amortization	(231)	(224)
Net, Total Amortized Intangible Assets	354	360
Trademarks/trade names
Indefinite-lived Intangible Assets (Excluding Goodwill) [Abstract]
Carrying Amount, Gross and Net	2,304	2,282
Miscellaneous
Indefinite-lived Intangible Assets (Excluding Goodwill) [Abstract]
Carrying Amount, Gross and Net	$ 90	$ 90