Fair Value of Intangible Assets and Related Accumulated Amortization Expense (Detail) (USD $) In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Finite-Lived Intangible Assets [Line Items]
Gross	$ 678	$ 678
Accumulated Amortization	(210)	(141)
Finite-Lived Intangible Assets, Net	468	537
Net	11,351	11,420
Indefinite-lived Intangible Assets	10,883	10,883
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Gross	339	339
Accumulated Amortization	(125)	(84)
Finite-Lived Intangible Assets, Net	214	255
Tradenames
Finite-Lived Intangible Assets [Line Items]
Gross	192	192
Accumulated Amortization	(41)	(28)
Finite-Lived Intangible Assets, Net	151	164
Reseller relationships
Finite-Lived Intangible Assets [Line Items]
Gross	95	95
Accumulated Amortization	(36)	(25)
Finite-Lived Intangible Assets, Net	59	70
Other Intangible Assets
Finite-Lived Intangible Assets [Line Items]
Gross	52	52
Accumulated Amortization	(8)	(4)
Finite-Lived Intangible Assets, Net	$ 44	$ 48