Derivative Instruments and Hedging Activities - Undesignated Hedges (Detail) (Derivatives Not Designated as Hedging Instruments [Member], Forward exchange contracts [Member], Other income (expense) [Member], USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014	Mar. 31, 2013
Derivatives Not Designated as Hedging Instruments [Member] | Forward exchange contracts [Member] | Other income (expense) [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amount of Gain (Loss) Recognized in Income on Derivatives	$ (1)	$ (9)	$ 5	$ 4