Segment Information and Geographic Data - Summary Information by Reportable Segment (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 28, 2020	Mar. 30, 2019	Mar. 28, 2020	Mar. 30, 2019
Segment Reporting Information [Line Items]
Net sales	$ 58,313	$ 58,015	$ 150,132	$ 142,325
Operating income	12,853	13,415	38,422	36,761
Americas
Segment Reporting Information [Line Items]
Net sales	25,473	25,596	66,840	62,536
Operating income	7,261	7,687	20,353	18,887
Europe
Segment Reporting Information [Line Items]
Net sales	14,294	13,054	37,567	33,417
Operating income	4,528	4,026	12,247	10,684
Greater China
Segment Reporting Information [Line Items]
Net sales	9,455	10,218	23,033	23,387
Operating income	3,758	3,607	9,121	8,921
Japan
Segment Reporting Information [Line Items]
Net sales	5,206	5,532	11,429	12,442
Operating income	2,236	2,390	5,014	5,404
Rest of Asia Pacific
Segment Reporting Information [Line Items]
Net sales	3,885	3,615	11,263	10,543
Operating income	$ 1,290	$ 1,096	$ 4,021	$ 3,656