Goodwill and Intangible Assets (Schedule Of Intangible Assets Subject To Amortization) (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 29, 2017	Sep. 29, 2017
Finite-Lived Intangible Assets [Line Items]
Total intangible assets, Gross Carrying Amount	$ 248.3	$ 242.4
Total intangible assets, Accumulated Amortization	(180.1)	(174.6)
Total intangible assets, Net Carrying Amount	$ 68.2	67.8
Customer relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted Average Amortization Period Remaining (Years)	5 years
Gross Carrying Amount	$ 78.5	78.5
Accumulated Amortization	(64.6)	(63.4)
Finite-Lived Intangible Assets, Net	$ 13.9	15.1
Developed technology and other[Member]
Finite-Lived Intangible Assets [Line Items]
Weighted Average Amortization Period Remaining (Years)	5 years
Gross Carrying Amount	$ 150.2	150.2
Accumulated Amortization	(113.6)	(110.9)
Finite-Lived Intangible Assets, Net	36.6	39.3
Trademarks [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	1.6	1.6
Accumulated Amortization	(0.4)	(0.3)
Finite-Lived Intangible Assets, Net	$ 1.2	1.3
Trade Names [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted Average Amortization Period Remaining (Years)	3 years
Computer Software, Intangible Asset [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 18.0	12.1
Accumulated Amortization	(1.5)	0.0
Finite-Lived Intangible Assets, Net	$ 16.5	$ 12.1
Software and Software Development Costs [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted Average Amortization Period Remaining (Years)	3 years