Summary of Significant Accounting Policies - Computation of Basic and Diluted Earnings Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended								12 Months Ended
	Sep. 24, 2016	Jun. 25, 2016	Mar. 26, 2016	Dec. 26, 2015	Sep. 26, 2015	Jun. 27, 2015	Mar. 28, 2015	Dec. 27, 2014	Sep. 24, 2016	Sep. 26, 2015	Sep. 27, 2014
Numerator:
Net income	$ 9,014	$ 7,796	$ 10,516	$ 18,361	$ 11,124	$ 10,677	$ 13,569	$ 18,024	$ 45,687	$ 53,394	$ 39,510
Denominator:
Weighted-average shares outstanding (in shares)									5,470,820	5,753,421	6,085,572
Effect of dilutive securities (in shares)									29,461	39,648	37,091
Weighted-average diluted shares (in shares)									5,500,281	5,793,069	6,122,663
Basic earnings per share (in dollars per share)	$ 1.68	$ 1.43	$ 1.91	$ 3.30	$ 1.97	$ 1.86	$ 2.34	$ 3.08	$ 8.35	$ 9.28	$ 6.49
Diluted earnings per share (in dollars per share)	$ 1.67	$ 1.42	$ 1.90	$ 3.28	$ 1.96	$ 1.85	$ 2.33	$ 3.06	$ 8.31	$ 9.22	$ 6.45