Restructuring Charges and Cost Savings Initiatives (Schedule Of Pre-Tax Charges) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		6 Months Ended			12 Months Ended
	Jan. 29, 2017	Jan. 31, 2016	Jan. 29, 2017		Jan. 31, 2016	Jul. 31, 2016	Aug. 02, 2015
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ (1)	$ 9	$ 0		$ 30
2015 Initiatives [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges	(1)	12	0		33	$ 35	$ 102
Restructuring and Related Cost, Incurred Cost	2	19	11		55	82	124
Restructuring charges and related costs, after tax	$ 1	$ 12	$ 7		$ 35	$ 52	$ 78
Restructuring charges per diluted share	$ 0.00	$ 0.04	$ 0.02		$ 0.11	$ 0.17	$ 0.25
Restructuring and Related Cost, Cost Incurred to Date	$ 217		$ 217
2015 Initiatives [Member] | Severance Pay And Benefits [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges			0
Restructuring and Related Cost, Cost Incurred to Date	128		128
2015 Initiatives [Member] | Implementation and Other Costs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Cost Incurred to Date	89		89
2015 Initiatives [Member] | General and Administrative Expense [Member] | Other Cost Savings Implementation Costs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	$ 3	$ 7	$ 11	[1]	$ 22	$ 47	$ 22
2014 Initiatives [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges		(3)				(4)
Restructuring charges and related costs, after tax		$ (2)				$ (3)
Restructuring charges per diluted share		$ 0.01				$ 0.01
Restructuring and Related Cost, Cost Incurred to Date						$ 50	54
2014 Initiatives [Member] | Severance Pay And Benefits [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges						(4)
Restructuring and Related Cost, Cost Incurred to Date						37	41
2014 Initiatives [Member] | Asset Impairment Accelerated Depreciation [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges						0
Restructuring and Related Cost, Cost Incurred to Date						12	12
2014 Initiatives [Member] | Other Restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges						0
Restructuring and Related Cost, Cost Incurred to Date						$ 1	$ 1

[1] Includes other costs recognized as incurred that are not reflected in the restructuring reserve in the Consolidated Balance Sheet. The costs are included in Administrative expenses in the Consolidated Statements of Earnings.