Pension And Postretirement Benefits (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Jul. 30, 2017	Jul. 31, 2016	Aug. 02, 2015
Defined Contribution Pension and Other Postretirement Plans Disclosure [Abstract]
Defined Contribution Plan, Cost Recognized	$ 34	$ 33	$ 31
Employees Not Covered By Collective Bargaining Agreements [Member]
Defined Contribution Pension and Other Postretirement Plans Disclosure [Abstract]
Defined Contribution Plan, Employer Matching Contribution, Percent of Match	100.00%
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay	4.00%
Employees Not Eligible To Participate In Defined Benefit Plans And Who Are Not Covered By Collective Bargaining Agreements Employer Contribution[Member]
Defined Contribution Pension and Other Postretirement Plans Disclosure [Abstract]
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay	3.00%
Pension Plan, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Recognized Net Loss Due to Curtailments	$ 0	0	$ 1
Defined Benefit Plan, Accumulated Benefit Obligation	$ 2,399	$ 2,557
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate	3.39%	4.19%	4.33%
Other Postretirement Benefit Plan, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Recognized Net Loss Due to Curtailments	$ 0	$ 0	$ 6
Defined Benefit Plan, Future Amortization of Prior Service Cost (Credit)	$ (27)
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate	3.20%	4.00%	4.00%
U.S. Pension Plan, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plans, Estimated Future Employer Contributions in Next Fiscal Year	$ 0
Non-U.S. Pension Plan, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plans, Estimated Future Employer Contributions in Next Fiscal Year	$ 5