Goodwill and Intangible Assets (Schedule Of Intangible Assets Subject To Amortization) (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 28, 2018	Sep. 28, 2018
Intangible Assets Excluding Goodwill [Line Items]
Intangible Assets, Gross (Excluding Goodwill)	$ 184.2	$ 187.2
Intangible Assets Excluding Goodwill Accumulated Amortization	54.1	43.5
Intangible assets, net	$ 130.1	143.7
Customer relationships [Member]
Intangible Assets Excluding Goodwill [Line Items]
Weighted Average Amortization Period (Years)	3 years 8 months 12 days
Gross Carrying Amount	$ 28.7	31.7
Accumulated Amortization	(14.9)	(13.2)
Net Carrying Amount	$ 13.8	18.5
Developed Technology Rights [Member]
Intangible Assets Excluding Goodwill [Line Items]
Weighted Average Amortization Period (Years)	5 years 3 months 18 days
Gross Carrying Amount	$ 89.9	89.9
Accumulated Amortization	(30.8)	(23.5)
Net Carrying Amount	59.1	66.4
Trademarks [Member]
Intangible Assets Excluding Goodwill [Line Items]
Gross Carrying Amount	1.6	1.6
Accumulated Amortization	(0.9)	(0.8)
Net Carrying Amount	$ 0.7	0.8
Computer Software, Intangible Asset [Member]
Intangible Assets Excluding Goodwill [Line Items]
Weighted Average Amortization Period (Years)	3 years
Gross Carrying Amount	$ 18.0	18.0
Accumulated Amortization	(7.5)	(6.0)
Net Carrying Amount	10.5	12.0
In Process Research and Development [Member]
Intangible Assets Excluding Goodwill [Line Items]
Gross Carrying Amount	46.0	46.0
Accumulated Amortization	0.0	0.0
Net Carrying Amount	$ 46.0	$ 46.0
Trade Names [Member]
Intangible Assets Excluding Goodwill [Line Items]
Weighted Average Amortization Period (Years)	3 years