Segment Information and Geographic Data - Summary Information by Reportable Segment (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017
Segment Reporting Information [Line Items]
Net sales	$ 53,265	$ 45,408	$ 202,695	$ 176,655
Operating income	12,612	10,768	54,780	48,224
Americas
Segment Reporting Information [Line Items]
Net sales	24,542	20,376	84,576	73,501
Operating income	7,496	6,420	26,580	23,582
Europe
Segment Reporting Information [Line Items]
Net sales	12,138	10,675	47,038	41,929
Operating income	3,892	2,984	15,044	12,571
Greater China
Segment Reporting Information [Line Items]
Net sales	9,551	8,004	40,531	34,963
Operating income	3,414	3,002	15,285	13,402
Japan
Segment Reporting Information [Line Items]
Net sales	3,867	3,624	16,572	13,875
Operating income	1,765	1,624	7,193	6,334
Rest of Asia Pacific
Segment Reporting Information [Line Items]
Net sales	3,167	2,729	13,978	12,387
Operating income	$ 1,127	$ 892	$ 4,980	$ 4,430