Goodwill and Other Intangible Assets - Other Intangible Assets (Details) - USD ($) $ in Millions	Mar. 31, 2016	Sep. 30, 2015	Mar. 31, 2015
Intangible Assets [Line Items]
Gross carrying amount, total intangible assets	$ 1,986	$ 1,904	$ 1,903
Net, Total Intangible Assets	1,576	1,516	1,558
Finite-Lived Intangible Assets, Gross [Abstract]
Gross Carrying Amount	1,443	1,362	1,360
Accumulated Amortization	(410)	(388)	(345)
Net, Total Amortized Intangible Assets	1,033	974	1,015
Patented Technology
Finite-Lived Intangible Assets, Gross [Abstract]
Gross Carrying Amount	47	80	82
Accumulated Amortization	(28)	(59)	(58)
Net, Total Amortized Intangible Assets	19	21	24
Customer Relationships
Finite-Lived Intangible Assets, Gross [Abstract]
Gross Carrying Amount	1,013	975	982
Accumulated Amortization	(238)	(206)	(180)
Net, Total Amortized Intangible Assets	775	769	802
Miscellaneous
Finite-Lived Intangible Assets, Gross [Abstract]
Gross Carrying Amount	383	307	296
Accumulated Amortization	(144)	(123)	(107)
Net, Total Amortized Intangible Assets	239	184	189
Trademarks
Indefinite-Lived Intangible Assets (Excluding Goodwill) [Abstract]
Carrying Amount, Gross and Net	$ 543	$ 542	$ 543