Intangible Assets - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Increase (Decrease) in Developed Technologies	$ 57
Intangible amortization expense		$ 552	$ 346	$ 84
Estimated aggregate amortization expense in 2016	525	525
Estimated aggregate amortization expense in 2017	515	515
Estimated aggregate amortization expense in 2018	510	510
Estimated aggregate amortization expense in 2019	509	509
Estimated aggregate amortization expense in 2020	$ 504	504
Developed technology | Respiratory Solutions | Disposal Group, Held-for-sale, Not Discontinued Operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Finite-Lived Intangible Assets, Period Increase (Decrease)		(117)
Acquired in-process research and development | Respiratory Solutions | Disposal Group, Held-for-sale, Not Discontinued Operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Indefinite-lived Intangible Assets, Period Increase (Decrease)		$ (80)