Income Taxes (Schedule of Unrecognized Tax Benefits Balance Sheet Location) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 29, 2017	Dec. 30, 2016	Sep. 30, 2016	Sep. 25, 2015	Sep. 26, 2014
Income Tax Contingency [Line Items]
Unrecognized Tax Benefits, Interest on Income Taxes Release	$ 2.7
Unrecognized Tax Benefits	182.5	$ 118.7	$ 114.8	$ 89.2	$ 82.0
Accrued and other current liabilities
Income Tax Contingency [Line Items]
Unrecognized Tax Benefits	1.5	0.0
Other Income Tax Liabilities
Income Tax Contingency [Line Items]
Unrecognized Tax Benefits	82.6	58.3
Deferred income tax liability (non-current)
Income Tax Contingency [Line Items]
Unrecognized Tax Benefits	98.4	60.4
Liabilities, Total [Member]
Income Tax Contingency [Line Items]
Unrecognized Tax Benefits	$ 182.5	$ 118.7