Supplemental Balance Sheet Information (Property, Plant And Equipment, net) (Details) - USD ($) $ in Millions	Mar. 29, 2020	Sep. 29, 2019
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 14,581.1	$ 14,273.5
Accumulated depreciation	(8,194.1)	(7,841.8)
Property, plant and equipment, net	6,387.0	6,431.7
Land [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	46.8	46.8
Buildings [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	575.9	691.5
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	8,169.4	7,948.6
Store Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	2,724.1	2,659.5
Roasting Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	799.8	769.6
Furniture, Fixtures and Other [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	1,881.0	1,799.0
Work in Progress [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 384.1	$ 358.5