Derivative Instruments and Hedging Activities - Effective Portion of Foreign Currency Forward Contracts Designated as Cash Flow Hedges (Detail) - Derivatives Designated as Hedging Instruments - Foreign currency forward contracts - USD ($) $ in Millions	12 Months Ended
	Sep. 29, 2017	Sep. 30, 2016	Oct. 02, 2015
Derivative [Line Items]
Gain (Loss) Recognized in Other Comprehensive Income (Effective Portion)	$ 0.0	$ (1.0)	$ 2.2
Gain (Loss) Reclassified from Accumulated Other Comprehensive Income into Net Earnings (Effective Portion)	$ 0.0	$ (1.0)	$ 3.8