Income Taxes (Provision for Income Taxes) (Details) - USD ($) $ in Millions	12 Months Ended
	Jul. 29, 2017	Jul. 30, 2016	Jul. 25, 2015
Federal:
Current	$ 1,300	$ 865	$ 1,583
Deferred	(42)	(93)	43
Total	1,258	772	1,626
State:
Current	86	78	130
Deferred	56	13	(20)
Total	142	91	110
Foreign:
Current	1,416	1,432	530
Deferred	(138)	(114)	(46)
Total	1,278	1,318	484
Total	$ 2,678	$ 2,181	$ 2,220