Restructuring Charges and Cost Savings Initiatives (Schedule Of Restructuring Activity And Related Reserves) (Details) - USD ($) $ 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 Reserve [Roll Forward]
Restructuring charges		$ (1)		$ 9	$ 0		$ 30
2015 Initiatives [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost		2		19	11		55	$ 82		$ 124
Restructuring Reserve [Roll Forward]
Restructuring charges		(1)		12	0		33	35		102
2015 Initiatives [Member] | Severance Pay And Benefits [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve, Noncurrent		6			6			17
Restructuring Reserve [Roll Forward]
Accrued Balance at beginning of period	[1]				73
Restructuring charges					0
Cash Payments					(29)
Accrued Balance at end of period		44	[2]		44	[2]		73	[1]
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	[3]	$ 22	$ 47		$ 22

[1] Includes $17 of severance pay and benefits recorded in Other liabilities in the Consolidated Balance Sheet.

[2] Includes $6 of severance pay and benefits recorded in Other liabilities in the Consolidated Balance Sheet.

[3] 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.