Restructuring Charges and Cost Savings Initiatives (Schedule Of Pre-Tax Charges) (Details) - USD ($) $ in Millions	12 Months Ended
	Jul. 30, 2017	Jul. 31, 2016	Aug. 02, 2015
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	$ 18	$ 31	$ 102
2015 Initiatives [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	18	35	102
Restructuring and Related Cost, Incurred Cost	58	82	124
Restructuring and Related Cost, Cost Incurred to Date	264
2015 Initiatives [Member] | Severance Pay And Benefits [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	7	34	87
Restructuring and Related Cost, Cost Incurred to Date	135
2015 Initiatives [Member] | Asset Impairment Accelerated Depreciation [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	12	0	0
Restructuring and Related Cost, Cost Incurred to Date	12
2015 Initiatives [Member] | Implementation and Other Related Costs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Cost Incurred to Date	117
2015 Initiatives [Member] | Other Restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	0	1	8
2015 Initiatives [Member] | General and Administrative Expense [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	36	47	22
2015 Initiatives [Member] | Cost Of Products Sold [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	$ 4	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.