Pension And Postretirement Benefits (Schedule Of Components of Benefit Expense) (Details) - USD ($) $ in Millions	12 Months Ended
	Aug. 01, 2021	Aug. 02, 2020	Jul. 28, 2019
Pension Plan, Defined Benefit [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Defined Benefit Plan, Service Cost	$ 18	$ 19	$ 21
Defined Benefit Plan, Interest Cost	41	65	82
Expected return on plan assets	(122)	(134)	(143)
Defined Benefit Plan, Amortization of Prior Service Cost (Credit)	0	0	1
Defined Benefit Plan, Actuarial (Gain) Loss	(159)	98	120
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement	(38)	43	28
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	(260)	91	109
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Defined Benefit Plan, Service Cost	0	1	1
Defined Benefit Plan, Interest Cost	4	6	8
Defined Benefit Plan, Amortization of Prior Service Cost (Credit)	(5)	(28)	(29)
Defined Benefit Plan, Actuarial (Gain) Loss	(6)	23	14
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	$ (7)	$ 2	$ (6)