Income Taxes (Provision for Income Taxes) (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 27, 2020	Sep. 29, 2019	Sep. 30, 2018
Income Tax Disclosure [Abstract]
Current taxes: U.S. federal	$ 49.9	$ 1,414.3	$ 156.2
Current taxes: U.S. state and local	36.9	447.8	52.0
Current taxes: Foreign	181.4	458.3	327.0
Total current taxes	268.2	2,320.4	535.2
Deferred taxes: U.S. federal	(8.4)	(1,074.5)	633.7
Deferred taxes: U.S. state and local	(4.8)	(322.4)	101.5
Deferred taxes: Foreign	(15.3)	(51.9)	(8.4)
Total deferred taxes	(28.5)	(1,448.8)	726.8
Total income tax expense	$ 239.7	$ 871.6	$ 1,262.0