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		6 Months Ended
	Apr. 01, 2017	Mar. 26, 2016	Apr. 01, 2017	Mar. 26, 2016
Numerator:
Net income	$ 11,029	$ 10,516	$ 28,920	$ 28,877
Denominator:
Weighted-average shares outstanding (in shares)	5,225,791	5,514,381	5,262,226	5,536,656
Effect of dilutive securities (in shares)	35,897	26,505	32,615	30,850
Weighted-average diluted shares (in shares)	5,261,688	5,540,886	5,294,841	5,567,506
Basic earnings per share (in dollars per share)	$ 2.11	$ 1.91	$ 5.50	$ 5.22
Diluted earnings per share (in dollars per share)	$ 2.10	$ 1.90	$ 5.46	$ 5.19