Comprehensive Income - Pre-tax Amounts Reclassified from AOCI into Consolidated Statements of Operations (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 28, 2019	Sep. 29, 2018	Sep. 30, 2017
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total cost of sales	$ 161,782	$ 163,756	$ 141,048
Other income/(expense), net	(1,807)	(2,005)	(2,745)
Total amounts reclassified from AOCI	(65,737)	(72,903)	$ (64,089)
Reclassifications out of AOCI
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total amounts reclassified from AOCI	134	466
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	103	486
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	(206)	214
Total cost of sales	(482)	(70)
Other income/(expense), net	784	344
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	7	(2)
Reclassifications out of AOCI | Unrealized (gains)/losses on marketable securities
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other income/(expense), net	$ 31	$ (20)