Income Taxes (Provision for Income Taxes) (Details) - USD ($) $ in Millions	12 Months Ended
	Jul. 28, 2018	Jul. 29, 2017	Jul. 30, 2016
Federal:
Current	$ 9,900	$ 1,300	$ 865
Deferred	1,156	(42)	(93)
Total	11,056	1,258	772
State:
Current	340	86	78
Deferred	(232)	56	13
Total	108	142	91
Foreign:
Current	1,789	1,416	1,432
Deferred	(24)	(138)	(114)
Total	1,765	1,278	1,318
Total	$ 12,929	$ 2,678	$ 2,181