Restructuring Charges and Cost Savings Initiatives (Schedule Of Pre-Tax Charges) (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended		12 Months Ended
		Apr. 29, 2018	Apr. 30, 2017	Apr. 29, 2018	Apr. 30, 2017	Jul. 30, 2017	Jul. 31, 2016	Aug. 02, 2015
Restructuring Cost and Reserve [Line Items]
Restructuring Charges		$ 24	$ 0	$ 59	$ 0
2015 Initiatives [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges		14	0	49	0	$ 18	$ 35	$ 102
Restructuring and Related Cost, Incurred Cost		60	7	139	18	58	82	124
Restructuring and Related Cost, Cost Incurred to Date		403		403
2015 Initiatives [Member] | Severance Pay And Benefits [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost				43
Restructuring and Related Cost, Cost Incurred to Date		180		180
2015 Initiatives [Member] | Asset Impairment Accelerated Depreciation [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost				19
Restructuring and Related Cost, Cost Incurred to Date		31		31
2015 Initiatives [Member] | Implementation and Other Related Costs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	[1]			72
Restructuring and Related Cost, Cost Incurred to Date		192		192
2015 Initiatives [Member] | Administrative expenses [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost		30	7	68	18	36	47	22
2015 Initiatives [Member] | Cost Of Products Sold [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost		14	0	20	0	4	0	0
2015 Initiatives [Member] | Marketing and selling expenses [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost		$ 2	$ 0	$ 2	$ 0	$ 0	$ 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, Cost of products sold, and Marketing and selling expenses in the Consolidated Statements of Earnings.