Derivative Instruments and Hedging Activities - Undesignated Hedges (Detail) (Not Designated as Hedging Instrument [Member], Forward exchange contracts [Member], Other income expense [Member], USD $) In Thousands, unless otherwise specified	3 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Not Designated as Hedging Instrument [Member] | Forward exchange contracts [Member] | Other income expense [Member]
Derivatives And Hedging Activities [Line Items]
Amount of Gain (Loss) Recognized in Income on Derivative	$ 13,084	$ (2,864)