Property, Equipment and Technology, Net - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011
Finite-Lived Intangible Assets [Line Items]
Technology, accumulated amortization	$ 959	$ 812
Depreciation and amortization	397	333	288
Depreciation and amortization, amortization expense on technology	69	68	63
Property, Equipment and Technology
Finite-Lived Intangible Assets [Line Items]
Depreciation and amortization	328	265	225
Technology and Software
Finite-Lived Intangible Assets [Line Items]
Depreciation and amortization, amortization expense on technology	$ 173	$ 132	$ 102