Summary of Significant Accounting Policies - Computation of Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended								12 Months Ended
	Sep. 26, 2020	Jun. 27, 2020	Mar. 28, 2020	Dec. 28, 2019	Sep. 28, 2019	Jun. 29, 2019	Mar. 30, 2019	Dec. 29, 2018	Sep. 26, 2020	Sep. 28, 2019	Sep. 29, 2018
Numerator:
Net income	$ 12,673	$ 11,253	$ 11,249	$ 22,236	$ 13,686	$ 10,044	$ 11,561	$ 19,965	$ 57,411	$ 55,256	$ 59,531
Denominator:
Weighted-average basic shares outstanding (in shares)									17,352,119	18,471,336	19,821,510
Effect of dilutive securities (in shares)									176,095	124,315	178,925
Weighted-average diluted shares (in shares)									17,528,214	18,595,651	20,000,435
Basic earnings per share (in dollars per share)	$ 0.74	$ 0.65	$ 0.64	$ 1.26	$ 0.76	$ 0.55	$ 0.62	$ 1.05	$ 3.31	$ 2.99	$ 3.00
Diluted earnings per share (in dollars per share)	$ 0.73	$ 0.65	$ 0.64	$ 1.25	$ 0.76	$ 0.55	$ 0.61	$ 1.05	$ 3.28	$ 2.97	$ 2.98