Revenue - Net Sales Disaggregated by Significant Products and Services (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 25, 2021	Dec. 26, 2020
Disaggregation of Revenue [Line Items]
Net sales	$ 123,945	$ 111,439
Revenue recognized that was included in deferred revenue at the beginning of the period	3,000	2,500
iPhone
Disaggregation of Revenue [Line Items]
Net sales	71,628	65,597
Mac
Disaggregation of Revenue [Line Items]
Net sales	10,852	8,675
iPad
Disaggregation of Revenue [Line Items]
Net sales	7,248	8,435
Wearables, Home and Accessories
Disaggregation of Revenue [Line Items]
Net sales	14,701	12,971
Services
Disaggregation of Revenue [Line Items]
Net sales	$ 19,516	$ 15,761