Pension And Postretirement Benefits (Schedule Of Components of Benefit Expense) (Details) - USD ($) $ in Millions	12 Months Ended
	Aug. 02, 2020	Jul. 28, 2019	Jul. 29, 2018
Discontinued Operations, Held-for-sale or Disposed of by Sale [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)		$ 13	$ (4)
Pension Plan, Defined Benefit [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Defined Benefit Plan, Service Cost	$ 19	21	24
Defined Benefit Plan, Interest Cost	65	82	74
Expected return on plan assets	(134)	(143)	(144)
Defined Benefit Plan, Amortization of Prior Service Cost (Credit)	0	1	0
Defined Benefit Plan, Actuarial (Gain) Loss	98	120	(104)
Defined Benefit Plan, Cost of Providing Special and Contractual Termination Benefits	0	0	2
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Curtailment	0	0	2
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement	43	28	0
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	91	109	(150)
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	6	8	7
Defined Benefit Plan, Amortization of Prior Service Cost (Credit)	(28)	(29)	(27)
Defined Benefit Plan, Actuarial (Gain) Loss	23	14	(16)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	$ 2	$ (6)	$ (35)