Supplemental Balance Sheet Information (Property, Plant and Equipment, net) (Details) - USD ($) $ in Millions	Sep. 29, 2019	Sep. 30, 2018
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 14,273.5	$ 13,197.1
Accumulated depreciation	(7,841.8)	(7,268.0)
Property, plant and equipment, net	6,431.7	5,929.1
Land [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	46.8	46.8
Building [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	691.5	557.3
Leasehold improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	7,948.6	7,372.8
Store equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	2,659.5	2,400.2
Roasting equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	769.6	658.8
Furniture, fixtures and other [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	1,799.0	1,659.3
Work in progress [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 358.5	$ 501.9