Pension And Postretirement Benefits (Schedule Of Components of Benefit Expense) (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 Disclosure [Line Items]
Service cost	$ 42	$ 57	$ 55
Interest cost	115	108	122
Expected return on plan assets	(176)	(177)	(178)
Amortization of Prior Service Cost (Credit)	(1)	(1)	0
Recognized net actuarial loss	76	108	74
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Curtailments	0	3	0
Defined Benefit Plan, Recognized Net Gain Loss Due to Settlements	22	0	0
Net periodic benefit expense	78	98	73
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	2	3	3
Interest cost	17	15	18
Amortization of Prior Service Cost (Credit)	(1)	(1)	(1)
Recognized net actuarial loss	13	15	9
Net periodic benefit expense	$ 31	$ 32	$ 29