Income Taxes (Schedule of Unrecognized Tax Benefits Balance Sheet Location) (Details) - USD ($) $ in Millions	Sep. 25, 2015	Sep. 26, 2014	Sep. 27, 2013	Sep. 28, 2012
Income Tax Contingency [Line Items]
Unrecognized tax benefits	$ 89.2	$ 82.0	$ 100.1	$ 165.5
Accrued and Other Current Liabilities
Income Tax Contingency [Line Items]
Unrecognized tax benefits	1.3	6.5
Other Income Tax Liabilities
Income Tax Contingency [Line Items]
Unrecognized tax benefits	80.0	70.7
Deferred income tax liability (non-current)
Income Tax Contingency [Line Items]
Unrecognized tax benefits	7.9	4.8
Liabilities, Total
Income Tax Contingency [Line Items]
Unrecognized tax benefits	$ 89.2	$ 82.0