Net Income per Share (Calculation Of Basic And Diluted Net Income Per Share) (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jan. 24, 2015	Jan. 25, 2014	Jan. 24, 2015	Jan. 25, 2014
Earnings Per Share [Abstract]
Net income	$ 2,397	$ 1,429	$ 4,225	$ 3,425
Weighted-average shares—basic (in shares)	5,117	5,294	5,115	5,336
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements (in shares)	43	33	44	47
Weighted-average shares—diluted (in shares)	5,160	5,327	5,159	5,383
Net income per share—basic	$ 0.47	$ 0.27	$ 0.83	$ 0.64
Net income per share—diluted	$ 0.46	$ 0.27	$ 0.82	$ 0.64
Antidilutive employee share-based awards, excluded (in shares)	83	278	156	252