Goodwill and Intangible Assets (Schedule Of Intangible Assets Subject To Amortization) (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 30, 2022	Sep. 30, 2022
Finite-Lived Intangible Assets [Line Items]
Accumulated Amortization	$ (417.6)	$ (376.7)
Total intangible assets, Gross Carrying Amount	1,790.6	1,821.4
Total intangible assets, Net Carrying Amount	$ 1,373.0	1,444.7
Customer relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted Average Amortization Period (Years)	2 years 3 months 18 days
Finite-Lived Intangible Assets, Gross	$ 154.6	154.6
Accumulated Amortization	(143.9)	(122.3)
Net Carrying Amount	$ 10.7	32.3
Computer Software, Intangible Asset [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted Average Amortization Period (Years)	2 years 8 months 12 days
Finite-Lived Intangible Assets, Gross	$ 74.3	105.1
Accumulated Amortization	(20.1)	(45.2)
Net Carrying Amount	54.2	59.9
In Process Research and Development [Member]
Finite-Lived Intangible Assets [Line Items]
Accumulated Amortization	0.0	0.0
Indefinite-lived Intangible Assets (Excluding Goodwill)	$ 273.1	280.8
Developed Technology Rights
Finite-Lived Intangible Assets [Line Items]
Weighted Average Amortization Period (Years)	6 years
Finite-Lived Intangible Assets, Gross	$ 1,288.6	1,280.9
Accumulated Amortization	(253.6)	(209.2)
Net Carrying Amount	$ 1,035.0	$ 1,071.7
Developed Technology Rights | Silicon Labs Industrial and Automotive Business
Finite-Lived Intangible Assets [Line Items]
Weighted Average Amortization Period (Years)	12 years