Business And Geographic Segment Information Business And Geographic Segment Information (Geographic Information, Net Sales) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Aug. 02, 2020	Apr. 26, 2020	Jan. 26, 2020	Oct. 27, 2019	Jul. 28, 2019	Apr. 28, 2019	Jan. 27, 2019	Oct. 28, 2018	Aug. 02, 2020	Jul. 28, 2019	Jul. 29, 2018
Segment Reporting Information [Line Items]
Net sales	$ 2,108	$ 2,238	$ 2,162	$ 2,183	$ 1,780	$ 1,953	$ 2,172	$ 2,202	$ 8,691	$ 8,107	$ 6,615
UNITED STATES
Segment Reporting Information [Line Items]
Net sales									8,165	7,492	6,068
Other Countries [Member]
Segment Reporting Information [Line Items]
Net sales									$ 526	$ 615	$ 547