Goodwill and Other Intangible Assets - Other Intangible Assets (Details) - USD ($) $ in Millions	Mar. 31, 2019	Sep. 30, 2018
Intangible Assets [Line Items]
Gross carrying amount, total intangible assets	$ 7,243	$ 7,222
Net, Total Intangible Assets	6,015	6,187
Finite-Lived Intangible Assets, Gross [Abstract]
Gross Carrying Amount	4,781	4,716
Accumulated Amortization	(1,228)	(1,035)
Net, Total Amortized Intangible Assets	3,553	3,681
Indefinite-lived Intangible Assets (Excluding Goodwill) [Abstract]
Carrying Amount, Gross and Net	2,462	2,506
Patented Technology
Finite-Lived Intangible Assets, Gross [Abstract]
Gross Carrying Amount	1,309	1,317
Accumulated Amortization	(310)	(251)
Net, Total Amortized Intangible Assets	999	1,066
Customer Relationships
Finite-Lived Intangible Assets, Gross [Abstract]
Gross Carrying Amount	2,930	2,941
Accumulated Amortization	(702)	(599)
Net, Total Amortized Intangible Assets	2,228	2,342
Miscellaneous
Finite-Lived Intangible Assets, Gross [Abstract]
Gross Carrying Amount	542	458
Accumulated Amortization	(216)	(185)
Net, Total Amortized Intangible Assets	326	273
Trademarks/trade names
Indefinite-lived Intangible Assets (Excluding Goodwill) [Abstract]
Carrying Amount, Gross and Net	2,372	2,386
Miscellaneous
Indefinite-lived Intangible Assets (Excluding Goodwill) [Abstract]
Carrying Amount, Gross and Net	$ 90	$ 120

Intangible Assets [Line Items]

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Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

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Amount before amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 340
-Section 50
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Amount of assets, excluding financial assets and goodwill, lacking physical substance and having a projected indefinite period of benefit.

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Amount before accumulated amortization of intangible assets, excluding goodwill.

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Sum of the carrying amounts of all intangible assets, excluding goodwill, as of the balance sheet date, net of accumulated amortization and impairment charges.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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