Consolidated Financial Statement Details - Other Income/(Expense), Net (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 28, 2019	Sep. 29, 2018	Sep. 30, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Interest and dividend income	$ 4,961	$ 5,686	$ 5,201
Interest expense	(3,576)	(3,240)	(2,323)
Other income/(expense), net	422	(441)	(133)
Total other income/(expense), net	$ 1,807	$ 2,005	$ 2,745