Net Income per Share (Calculation Of Basic And Diluted Net Income Per Share) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jan. 23, 2016	Jan. 24, 2015	Jan. 23, 2016	Jan. 24, 2015
Earnings Per Share [Abstract]
Net income	$ 3,147	$ 2,397	$ 5,577	$ 4,225
Weighted-average shares—basic (in shares)	5,070	5,117	5,075	5,115
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements (in shares)	27	43	31	44
Weighted-average shares—diluted (in shares)	5,097	5,160	5,106	5,159
Net income per share—basic	$ 0.62	$ 0.47	$ 1.10	$ 0.83
Net income per share—diluted	$ 0.62	$ 0.46	$ 1.09	$ 0.82
Antidilutive employee share-based awards, excluded (in shares)	98	83	133	156