Comprehensive Income - Pre-tax Amounts Reclassified from AOCI into the Condensed Consolidated Statements of Operations (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 28, 2019	Dec. 29, 2018
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total cost of sales	$ 56,602	$ 52,279
Other income/(expense), net	(349)	(560)
Total amounts reclassified from AOCI	(25,918)	(23,906)
Reclassifications out of AOCI
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total amounts reclassified from AOCI	(502)	132
Reclassifications out of AOCI | Unrealized (gains)/losses on derivative instruments
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total amounts reclassified from AOCI	(489)	85
Reclassifications out of AOCI | Unrealized (gains)/losses on derivative instruments | Foreign exchange contracts
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total net sales	(97)	63
Total cost of sales	(171)	(375)
Other income/(expense), net	(223)	396
Reclassifications out of AOCI | Unrealized (gains)/losses on derivative instruments | Interest rate contracts
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other income/(expense), net	2	1
Reclassifications out of AOCI | Unrealized (gains)/losses on marketable securities
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other income/(expense), net	$ (13)	$ 47