Derivatives - Gain (Loss) on Fair Value Hedges Recognized in Earnings (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 28, 2019	Dec. 29, 2018
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Foreign Currency Derivative Instruments Not Designated as Hedging Instruments	$ 0.0	$ (1.7)
Derivative instruments not designated as hedges, gain (loss)	(3.2)	5.1
Forward foreign currency contracts
Derivative Instruments, Gain (Loss) [Line Items]
Forward foreign currency contracts	(1.5)	5.1
Foreign currency option contracts
Derivative Instruments, Gain (Loss) [Line Items]
Derivative instruments not designated as hedges, gain (loss)	$ (1.7)	$ 0.0