Recent Accounting Pronouncements Schedule of Changes (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Apr. 29, 2018	Apr. 30, 2017	Apr. 29, 2018	Apr. 30, 2017
Cost of products sold	$ 1,507	$ 1,188	$ 4,299	$ 3,899
Marketing and selling expenses	232	212	679	682
Administrative expenses	163	142	477	408
Research and development expenses	27	28	84	80
Other expenses / (income)	$ 647	(15)	$ 688	197
Accounting Standards Update 2017-07 [Member]
Cost of products sold		13		17
Marketing and selling expenses		3		8
Administrative expenses		2		6
Research and development expenses		1		2
Other expenses / (income)		$ (19)		$ (33)