Pension And Postretirement Benefits (Schedule of Change in Benefit Obligation) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Jul. 28, 2013	Jul. 29, 2012	Jul. 31, 2011
Pension Plans, Defined Benefit [Member]
Defined Benefit Plan, Benefit Obligation	$ 2,489	$ 2,748	$ 2,388
Defined Benefit Plan, Service Cost	57	55	58
Defined Benefit Plan, Interest Cost	108	122	121
Defined Benefit Plan, Actuarial (Gain) Loss	(230)	361
Defined Benefit Plan, Contributions by Plan Participants	0	0
Defined Benefit Plan, Benefits Paid	(172)	(157)
Defined Benefit Plan, Gross Prescription Drug Subsidy Receipts Received	0	0
Other changes in benefit obligation	(3)	(5)
Defined Benefit Plan, Curtailments	(2)	0
Defined Benefit Plan, Foreign Currency Exchange Rate Gain (Loss)	(17)	(16)
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan, Benefit Obligation	390	413	374
Defined Benefit Plan, Service Cost	3	3	3
Defined Benefit Plan, Interest Cost	15	18	18
Defined Benefit Plan, Actuarial (Gain) Loss	(13)	47
Defined Benefit Plan, Contributions by Plan Participants	6	6
Defined Benefit Plan, Benefits Paid	(36)	(38)
Defined Benefit Plan, Gross Prescription Drug Subsidy Receipts Received	2	3
Other changes in benefit obligation	0	0
Defined Benefit Plan, Curtailments	0	0
Defined Benefit Plan, Foreign Currency Exchange Rate Gain (Loss)	$ 0	$ 0