Intangible Assets - Components of Intangible Assets (Detail) - USD ($) $ in Millions	Jun. 30, 2015	Sep. 30, 2014
Finite And Indefinite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 7,653	$ 1,308
Accumulated Amortization	756	594
Unamortized intangible assets, Total	228	46
Acquired In-Process Research and Development [Member]
Finite And Indefinite Lived Intangible Assets [Line Items]
Unamortized intangible assets, Total	226	44
Trademarks [Member]
Finite And Indefinite Lived Intangible Assets [Line Items]
Unamortized intangible assets, Total	2	2
Customer Relationships [Member]
Finite And Indefinite Lived Intangible Assets [Line Items]
Gross Carrying Amount	3,375	10
Accumulated Amortization	62	2
Developed Technology [Member]
Finite And Indefinite Lived Intangible Assets [Line Items]
Gross Carrying Amount	3,412	893
Accumulated Amortization	449	379
Product Rights [Member]
Finite And Indefinite Lived Intangible Assets [Line Items]
Gross Carrying Amount	130	148
Accumulated Amortization	34	31
Trademarks [Member]
Finite And Indefinite Lived Intangible Assets [Line Items]
Gross Carrying Amount	405	27
Accumulated Amortization	22	19
Patents and Other [Member]
Finite And Indefinite Lived Intangible Assets [Line Items]
Gross Carrying Amount	331	232
Accumulated Amortization	$ 189	$ 163