Derivative Instruments and Hedging Activities - Undesignated Hedges (Detail) (Derivatives Not Designated as Hedging Instruments [Member], Forward Exchange Contracts [Member], Other Income (Expense), Net [Member], USD $) In Millions, unless otherwise specified	3 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Derivatives Not Designated as Hedging Instruments [Member] | Forward Exchange Contracts [Member] | Other Income (Expense), Net [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amount of Gain (Loss) Recognized in Income on Derivatives	$ (2)	$ 6