Goodwill and Intangible Assets (Schedule Of Intangible Assets Subject To Amortization) (Details) - USD ($) $ in Millions	9 Months Ended
	Jun. 28, 2019	Sep. 28, 2018
Finite-Lived Intangible Assets [Line Items]
Accumulated Amortization	$ (84.4)	$ (43.5)
Total intangible assets, Gross Carrying Amount	198.5	187.2
Total intangible assets, Net Carrying Amount	$ 114.1	143.7
Customer relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted Average Amortization Period (Years)	3 years 4 months 24 days
Finite-Lived Intangible Assets, Gross	$ 31.7	31.7
Accumulated Amortization	(23.8)	(13.2)
Net Carrying Amount	$ 7.9	18.5
Technology-Based Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted Average Amortization Period (Years)	4 years 1 month 6 days
Finite-Lived Intangible Assets, Gross	$ 100.0	89.9
Accumulated Amortization	(46.4)	(23.5)
Net Carrying Amount	$ 53.6	66.4
Trade Names [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted Average Amortization Period (Years)	3 years
Finite-Lived Intangible Assets, Gross	$ 1.6	1.6
Accumulated Amortization	(1.2)	(0.8)
Net Carrying Amount	$ 0.4	0.8
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	$ 29.3	18.0
Accumulated Amortization	(13.0)	(6.0)
Net Carrying Amount	$ 16.3	12.0
In Process Research and Development [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted Average Amortization Period (Years)	0 years
Finite-Lived Intangible Assets, Gross	$ 35.9	46.0
Accumulated Amortization	0.0	0.0
Net Carrying Amount	$ 35.9	$ 46.0