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. 29, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 30, 2017	Sep. 30, 2017	Jul. 01, 2017	Apr. 01, 2017	Dec. 31, 2016	Sep. 29, 2018	Sep. 30, 2017	Sep. 24, 2016
Numerator:
Net income	$ 14,125	$ 11,519	$ 13,822	$ 20,065	$ 10,714	$ 8,717	$ 11,029	$ 17,891	$ 59,531	$ 48,351	$ 45,687
Denominator:
Weighted-average basic shares outstanding (in shares)									4,955,377	5,217,242	5,470,820
Effect of dilutive securities (in shares)									44,732	34,450	29,461
Weighted-average diluted shares (in shares)									5,000,109	5,251,692	5,500,281
Basic earnings per share (in dollars per share)	$ 2.94	$ 2.36	$ 2.75	$ 3.92	$ 2.08	$ 1.68	$ 2.11	$ 3.38	$ 12.01	$ 9.27	$ 8.35
Diluted earnings per share (in dollars per share)	$ 2.91	$ 2.34	$ 2.73	$ 3.89	$ 2.07	$ 1.67	$ 2.10	$ 3.36	$ 11.91	$ 9.21	$ 8.31