Pension And Postretirement Benefits (Schedule of Change in Benefit Obligation) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Aug. 03, 2014	Jul. 28, 2013	Jul. 29, 2012
Pension Plan, Defined Benefit [Member]
Defined Benefit Plan, Benefit Obligation	$ 2,489	$ 2,748
Defined Benefit Plan, Service Cost	42	57	55
Defined Benefit Plan, Interest Cost	115	108	122
Defined Benefit Plan, Actuarial Gain (Loss)	154	(230)
Defined Benefit Plan, Contributions by Plan Participants	0	0
Defined Benefit Plan, Benefits Paid	(191)	(172)
Defined Benefit Plan, Gross Prescription Drug Subsidy Receipts Received	0	0
Defined Benefit Plan, Other Changes	(4)	(3)
Defined Benefit Plan, Settlements, Benefit Obligation	(43)	0
Defined Benefit Plan, Curtailments	0	(2)
Defined Benefit Plan, Foreign Currency Exchange Rate Gain (Loss)	(12)	(17)
Defined Benefit Plan, Divestitures, Benefit Obligation	(11)	0
Defined Benefit Plan, Benefit Obligation	2,539	2,489	2,748
Other Postretirement Benefit Plan, Defined Benefit [Member]
Defined Benefit Plan, Benefit Obligation	390	413
Defined Benefit Plan, Service Cost	2	3	3
Defined Benefit Plan, Interest Cost	17	15	18
Defined Benefit Plan, Actuarial Gain (Loss)	5	(13)
Defined Benefit Plan, Contributions by Plan Participants	6	6
Defined Benefit Plan, Benefits Paid	(35)	(36)
Defined Benefit Plan, Gross Prescription Drug Subsidy Receipts Received	3	2
Defined Benefit Plan, Other Changes	0	0
Defined Benefit Plan, Settlements, Benefit Obligation	0	0
Defined Benefit Plan, Curtailments	0	0
Defined Benefit Plan, Foreign Currency Exchange Rate Gain (Loss)	0	0
Defined Benefit Plan, Divestitures, Benefit Obligation	0	0
Defined Benefit Plan, Benefit Obligation	$ 388	$ 390	$ 413