Pension And Postretirement Benefits (Schedule Of Components of Benefit Expense) (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 Disclosure [Line Items]
Service cost	$ 57	$ 55	$ 58
Interest cost	108	122	121
Expected return on plan assets	(177)	(178)	(178)
Amortization of Prior Service Cost (Credit)	(1)	0	1
Recognized net actuarial loss	108	74	70
Curtailment loss	3	0	0
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Settlements	0	0	(1)
Net periodic benefit expense	98	73	71
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	3	3	3
Interest cost	15	18	18
Amortization of Prior Service Cost (Credit)	(1)	(1)	(1)
Recognized net actuarial loss	15	9	7
Net periodic benefit expense	$ 32	$ 29	$ 27