Revenue Recognition - Net Sales Disaggregated by Significant Products and Services (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 26, 2021	Jun. 27, 2020	Jun. 26, 2021	Jun. 27, 2020
Disaggregation of Revenue [Line Items]
Net sales	$ 81,434	$ 59,685	$ 282,457	$ 209,817
Revenue recognized that was included in deferred revenue at the beginning of the period	3,000	2,100	5,500	4,000
iPhone
Disaggregation of Revenue [Line Items]
Net sales	39,570	26,418	153,105	111,337
Mac
Disaggregation of Revenue [Line Items]
Net sales	8,235	7,079	26,012	19,590
iPad
Disaggregation of Revenue [Line Items]
Net sales	7,368	6,582	23,610	16,927
Wearables, Home and Accessories
Disaggregation of Revenue [Line Items]
Net sales	8,775	6,450	29,582	22,744
Services
Disaggregation of Revenue [Line Items]
Net sales	$ 17,486	$ 13,156	$ 50,148	$ 39,219