Intangible Assets - Components of Intangible Assets (Detail) - USD ($) $ in Millions	Sep. 30, 2015	Sep. 30, 2014
Finite And Indefinite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 7,723	$ 1,308
Accumulated Amortization	903	594
Unamortized intangible assets	205	46
Acquired in-process research and development
Finite And Indefinite Lived Intangible Assets [Line Items]
Unamortized intangible assets	203	44
Trademarks
Finite And Indefinite Lived Intangible Assets [Line Items]
Unamortized intangible assets	2	2
Customer relationships
Finite And Indefinite Lived Intangible Assets [Line Items]
Gross Carrying Amount	3,370	10
Accumulated Amortization	120	2
Developed technology
Finite And Indefinite Lived Intangible Assets [Line Items]
Gross Carrying Amount	3,487	893
Accumulated Amortization	510	379
Product rights
Finite And Indefinite Lived Intangible Assets [Line Items]
Gross Carrying Amount	128	148
Accumulated Amortization	35	31
Trademarks
Finite And Indefinite Lived Intangible Assets [Line Items]
Gross Carrying Amount	405	27
Accumulated Amortization	26	19
Patents and other
Finite And Indefinite Lived Intangible Assets [Line Items]
Gross Carrying Amount	333	232
Accumulated Amortization	$ 212	$ 163