Goodwill and Other Intangible Assets Other Intangible Assets (Details) - USD ($) $ in Millions	Sep. 30, 2017	Sep. 30, 2016
Intangible Assets [Line Items]
Future amortization expense, 2017	$ 375
Gross carrying amount, total intangible assets	7,511	$ 7,920
Net, Total Intangible Assets	6,741	7,540
Finite-Lived Intangible Assets, Gross [Abstract]
Gross Carrying Amount	4,885	5,215
Accumulated Amortization	(770)	(380)
Net, Total Amortized Intangible Assets	4,115	4,835
Indefinite-Lived Intangible Assets (Excluding Goodwill) [Abstract]
Carrying Amount, Gross and Net	2,626	2,705
Patented Technology
Finite-Lived Intangible Assets, Gross [Abstract]
Gross Carrying Amount	1,328	1,528
Accumulated Amortization	(137)	(24)
Net, Total Amortized Intangible Assets	1,191	1,504
Customer Relationships
Finite-Lived Intangible Assets, Gross [Abstract]
Gross Carrying Amount	3,168	3,168
Accumulated Amortization	(486)	(226)
Net, Total Amortized Intangible Assets	2,682	2,942
Miscellaneous
Finite-Lived Intangible Assets, Gross [Abstract]
Gross Carrying Amount	389	519
Accumulated Amortization	(147)	(130)
Net, Total Amortized Intangible Assets	242	389
Trademarks
Indefinite-Lived Intangible Assets (Excluding Goodwill) [Abstract]
Carrying Amount, Gross and Net	2,483	2,555
Miscellaneous
Indefinite-Lived Intangible Assets (Excluding Goodwill) [Abstract]
Carrying Amount, Gross and Net	$ 143	$ 150