Condensed Consolidated Financial Statement Details - Other Income/(Expense), Net (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 30, 2019	Mar. 31, 2018	Mar. 30, 2019	Mar. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Interest and dividend income	$ 1,358	$ 1,505	$ 2,665	$ 2,957
Interest expense	(1,010)	(792)	(1,900)	(1,526)
Other income/(expense), net	30	(439)	173	(401)
Total other income/(expense), net	$ 378	$ 274	$ 938	$ 1,030