Business And Geographic Segment Information Business And Geographic Segment Information (Geographic Information, Net Sales) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Jul. 30, 2017	Apr. 30, 2017	Jan. 29, 2017	Oct. 30, 2016	Jul. 31, 2016	May 01, 2016	Jan. 31, 2016	Nov. 01, 2015	Jul. 30, 2017	Jul. 31, 2016	Aug. 02, 2015
Segment Reporting Information [Line Items]
Net sales	$ 1,664	$ 1,853	$ 2,171	$ 2,202	$ 1,687	$ 1,870	$ 2,201	$ 2,203	$ 7,890	$ 7,961	$ 8,082
UNITED STATES
Segment Reporting Information [Line Items]
Net sales									6,357	6,437	6,400
AUSTRALIA
Segment Reporting Information [Line Items]
Net sales									610	590	646
Other Countries [Member]
Segment Reporting Information [Line Items]
Net sales									$ 923	$ 934	$ 1,036