Pension And Postretirement Benefits (Schedule Of Components of Benefit Expense) (Details) - USD ($) $ in Millions	12 Months Ended
	Jul. 28, 2019	Jul. 29, 2018	Jul. 30, 2017
Pension Plan, Defined Benefit [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Defined Benefit Plan, Service Cost	$ 21	$ 24	$ 26
Defined Benefit Plan, Interest Cost	82	74	86
Expected return on plan assets	(143)	(144)	(144)
Defined Benefit Plan, Amortization of Prior Service Cost (Credit)	1	0	0
Defined Benefit Plan, Actuarial (Gain) Loss	120	(104)	(198)
Defined Benefit Plan, Cost of Providing Special and Contractual Termination Benefits	0	2	0
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Curtailment	0	2	0
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement	28	0	0
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	109	(150)	(230)
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Defined Benefit Plan, Service Cost	1	1	1
Defined Benefit Plan, Interest Cost	8	7	10
Defined Benefit Plan, Amortization of Prior Service Cost (Credit)	(29)	(27)	(25)
Defined Benefit Plan, Actuarial (Gain) Loss	14	(16)	(14)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	$ (6)	$ (35)	$ (28)