Income Taxes (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 29, 2019	Sep. 30, 2018	Oct. 01, 2017	Oct. 02, 2016
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%	24.50%	35.00%
Gross unrecognized tax benefits	$ 132.1	$ 224.6	$ 196.9	$ 146.5
Unrecognized tax benefits affecting the effective tax rate if recognized	113.2
Interest and penalties expense/(benefit) recognized in income tax expense	2.8	0.5	$ 5.2
Accrued interest and penalties	10.0	$ 12.8
expirationbeginningfiscal2020 [Member] [Domain]
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Foreign net operating loss carryforwards	246.2
expirationbeginningfiscal2024 [Member]
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Deferred Tax Assets, Operating Loss Carryforwards, Domestic	78.1
Tax credit carryforward	3.5
expirationindefinite [Member]
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Deferred Tax Assets, Operating Loss Carryforwards, Domestic	41.8
Foreign net operating loss carryforwards	$ 109.5