Recent Accounting Pronouncements Schedule of Changes (Details) - USD ($) $ in Millions	12 Months Ended
	Jul. 29, 2018	Jul. 30, 2017	Jul. 31, 2016
Cost of products sold	$ 5,869	$ 4,965	$ 5,033
Marketing and selling expenses	902	855	852
Administrative expenses	654	550	575
Research and development expenses	110	111	105
Other expenses / (Income)	$ (619)	9	(405)
Accounting Standards Update 2017-07 [Member]
Cost of products sold		134	(148)
Marketing and selling expenses		38	(41)
Administrative expenses		62	(66)
Research and development expenses		13	(19)
Other expenses / (Income)		$ 247	$ (274)