Derivatives - Schedule Of Change in Fair Value Of Derivative Contracts (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 26, 2020	Dec. 28, 2019	Sep. 26, 2020
Derivatives not designated as hedging instruments
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain (Loss) on Derivative, Net	$ (4.1)	$ 0.0
Unrealized Gain (Loss) on Derivatives	(14.6)	(3.0)
Forward foreign currency contracts | Derivatives not designated as hedging instruments
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain (Loss) on Derivative, Net	(2.9)	0.0
Unrealized Gain (Loss) on Derivatives	(6.6)	(1.5)
Forward foreign currency contracts | Derivatives not designated as hedging instruments | Accrued Liabilities
Derivative Instruments, Gain (Loss) [Line Items]
Interest rate swap at fair value	6.0		$ 0.0
Foreign currency option contracts | Derivatives not designated as hedging instruments
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain (Loss) on Derivative, Net	(1.2)	0.0
Unrealized Gain (Loss) on Derivatives	(8.0)	$ (1.5)
Interest Rate Swap
Derivative Instruments, Gain (Loss) [Line Items]
Interest rate swap at fair value	30.7
Interest Rate Swap | Derivatives not designated as hedging instruments | Accrued Liabilities
Derivative Instruments, Gain (Loss) [Line Items]
Interest rate swap at fair value	11.1		8.2
Interest Rate Swap | Derivatives not designated as hedging instruments | Other Noncurrent Liabilities
Derivative Instruments, Gain (Loss) [Line Items]
Interest rate swap at fair value	$ 19.6		$ 23.0