Recent Accounting Pronouncements Schedule of Changes (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jan. 28, 2018	Jan. 29, 2017	Jan. 28, 2018	Jan. 29, 2017
Cost of products sold	$ 1,414	$ 1,360	$ 2,792	$ 2,711
Marketing and selling expenses	228	240	447	470
Administrative expenses	165	141	314	266
Research and development expenses	27	25	57	52
Other expenses / (income)	$ 70	201	$ 41	212
Accounting Standards Update 2017-07 [Member]
Cost of products sold		14		4
Marketing and selling expenses		3		5
Administrative expenses		2		4
Research and development expenses		0		1
Other expenses / (income)		$ (19)		$ (14)