Comprehensive Income - Pre-tax Amounts Reclassified from AOCI into the Condensed Consolidated Statements of Operations (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 30, 2019	Mar. 31, 2018	Mar. 30, 2019	Mar. 31, 2018
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total cost of sales	$ 36,194	$ 37,715	$ 88,473	$ 92,096
Other income/(expense), net	(378)	(274)	(938)	(1,030)
Total amounts reclassified from AOCI	(13,793)	(16,168)	(37,699)	(43,198)
Reclassifications out of AOCI
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total amounts reclassified from AOCI	(83)	(248)	49	(241)
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	(119)	(284)	(34)	(161)
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)	87	(34)	271
Total cost of sales	(76)	21	(451)	(6)
Other income/(expense), net	52	(390)	448	(423)
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	(2)	3	(3)
Reclassifications out of AOCI | Unrealized (gains)/losses on marketable securities
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other income/(expense), net	$ 36	$ 36	$ 83	$ (80)