Gains (Losses) Related to Foreign Currency Forward Exchange Contracts that are Not Designated as Hedging Instruments (Detail) (Selling, general and administrative expenses, USD $) In Millions, unless otherwise specified	12 Months Ended
	Sep. 26, 2014	Sep. 27, 2013	Sep. 28, 2012
Selling, general and administrative expenses
Derivative [Line Items]
Amount of Gain Recognized in Net Earnings on Derivative not designated as hedging instrument	$ 13.7	$ 9.6	$ 5.0