Comprehensive Income - Pre-tax Amounts Reclassified from AOCI into the Consolidated Statements of Operations (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 26, 2020	Sep. 28, 2019	Sep. 29, 2018
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total cost of sales	$ 169,559	$ 161,782	$ 163,756
Other income/(expense), net	(803)	(1,807)	(2,005)
Total amounts reclassified from AOCI	(67,091)	(65,737)	$ (72,903)
Reclassifications out of AOCI
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total amounts reclassified from AOCI	(1,627)	134
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	(1,545)	103
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	(365)	(206)
Total cost of sales	(584)	(482)
Other income/(expense), net	(604)	784
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	8	7
Reclassifications out of AOCI | Unrealized (gains)/losses on marketable debt securities
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other income/(expense), net	$ (82)	$ 31