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. 28, 2019	Jun. 29, 2019	Mar. 30, 2019	Dec. 29, 2018	Sep. 29, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 30, 2017	Sep. 28, 2019	Sep. 29, 2018	Sep. 30, 2017
Numerator:
Net income	$ 13,686	$ 10,044	$ 11,561	$ 19,965	$ 14,125	$ 11,519	$ 13,822	$ 20,065	$ 55,256	$ 59,531	$ 48,351
Denominator:
Weighted-average basic shares outstanding (in shares)									4,617,834	4,955,377	5,217,242
Effect of dilutive securities (in shares)									31,079	44,732	34,450
Weighted-average diluted shares (in shares)									4,648,913	5,000,109	5,251,692
Basic earnings per share (in dollars per share)	$ 3.05	$ 2.20	$ 2.47	$ 4.22	$ 2.94	$ 2.36	$ 2.75	$ 3.92	$ 11.97	$ 12.01	$ 9.27
Diluted earnings per share (in dollars per share)	$ 3.03	$ 2.18	$ 2.46	$ 4.18	$ 2.91	$ 2.34	$ 2.73	$ 3.89	$ 11.89	$ 11.91	$ 9.21