Restructuring Charges and Cost Savings Initiatives (Schedule Of Pre-Tax Charges) (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended		12 Months Ended
		Jan. 28, 2018	Jan. 29, 2017	Jan. 28, 2018	Jan. 29, 2017	Jul. 30, 2017	Jul. 31, 2016	Aug. 02, 2015
Restructuring Cost and Reserve [Line Items]
Restructuring Charges		$ 33	$ (1)	$ 35	$ 0
2015 Initiatives [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges		33	(1)	35	0	$ 18	$ 35	$ 102
Restructuring and Related Cost, Incurred Cost		60	2	79	11	58	82	124
Restructuring and Related Cost, Cost Incurred to Date		343		343
2015 Initiatives [Member] | Severance Pay And Benefits [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost				30
Restructuring and Related Cost, Cost Incurred to Date		167		167
2015 Initiatives [Member] | Asset Impairment Accelerated Depreciation [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost				7
Restructuring and Related Cost, Cost Incurred to Date		19		19
2015 Initiatives [Member] | Implementation and Other Related Costs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	[1]			37
Restructuring and Related Cost, Cost Incurred to Date		157		157
2015 Initiatives [Member] | General and Administrative Expense [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost		26	3	38	11	36	47	22
2015 Initiatives [Member] | Cost Of Products Sold [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost		$ 1	$ 0	$ 6	$ 0	$ 4	$ 0	$ 0

[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 and Cost of products sold in the Consolidated Statements of Earnings.