Goodwill and Intangible Assets (Schedule of Intangible Assets Excluding Goodwill) (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 29, 2017	Sep. 30, 2016
Intangible Assets Excluding Goodwill [Line Items]
Gross carrying amount	$ 242.4	$ 213.9
Accumulated amortization	(174.6)	(146.9)
Net carrying amount	$ 67.8	67.0
Customer Relationships [Member]
Intangible Assets Excluding Goodwill [Line Items]
Weighted average amortization period (years)	5 years
Gross carrying amount	$ 78.5	78.5
Accumulated amortization	(63.4)	(57.7)
Net carrying amount	$ 15.1	20.8
Developed Technology and Other [Member]
Intangible Assets Excluding Goodwill [Line Items]
Weighted average amortization period (years)	5 years
Gross carrying amount	$ 150.2	133.8
Accumulated amortization	(110.9)	(89.2)
Net carrying amount	$ 39.3	44.6
Trademarks [Member]
Intangible Assets Excluding Goodwill [Line Items]
Weighted average amortization period (years)	3 years
Gross carrying amount	$ 1.6	1.6
Accumulated amortization	(0.3)	0.0
Net carrying amount	$ 1.3	1.6
Computer Software, Intangible Asset [Member]
Intangible Assets Excluding Goodwill [Line Items]
Weighted average amortization period (years)	3 years
Gross carrying amount	$ 12.1	0.0
Accumulated amortization	0.0	0.0
Net carrying amount	$ 12.1	$ 0.0