Supplemental Balance Sheet Information (Property, Plant And Equipment, net) (Details) - USD ($) $ in Millions	Jun. 27, 2021	Sep. 27, 2020
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 14,472.5	$ 14,155.3
Accumulated depreciation	(8,321.1)	(7,913.9)
Property, plant and equipment, net	6,151.4	6,241.4
Land [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	46.2	46.0
Buildings [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	588.0	586.8
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	8,402.4	8,262.6
Store Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	2,854.1	2,800.3
Roasting Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	844.3	796.6
Furniture, Fixtures and Other [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	1,340.5	1,285.7
Work in Progress [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 397.0	$ 377.3