Restructuring Charges and Cost Savings Initiatives (Schedule Of Pre-Tax Charges) (Details) - USD ($) $ in Millions	12 Months Ended
	Jul. 29, 2018	Jul. 30, 2017	Jul. 31, 2016	Aug. 02, 2015
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	$ 62	$ 18	$ 31
2015 Initiatives [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	49	18	35	$ 102
Restructuring and Related Cost, Incurred Cost	185	58	82	124
Restructuring and Related Cost, Cost Incurred to Date	449
2015 Initiatives [Member] | Severance Pay And Benefits [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	43	7	34	87
Restructuring and Related Cost, Cost Incurred to Date	180
2015 Initiatives [Member] | Asset Impairment Accelerated Depreciation [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	33	12	0	0
Restructuring and Related Cost, Cost Incurred to Date	45
2015 Initiatives [Member] | Implementation Costs and Other Related Costs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Cost Incurred to Date	224
2015 Initiatives [Member] | Other Restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	0	0	1	8
2015 Initiatives [Member] | General and Administrative Expense [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	88	36	47	22
2015 Initiatives [Member] | Cost Of Products Sold [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	45	4	0	0
2015 Initiatives [Member] | Selling and Marketing Expense [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	$ 3	$ 0	0	0
2014 Initiatives [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges			(4)
Restructuring and Related Cost, Cost Incurred to Date			50	54	[1]
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	[1]
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	[1]
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]

[1] Recognized as of August 2, 2015.