Pension And Postretirement Benefits (Schedule of Change in Benefit Obligation) (Details) - USD ($) $ in Millions	12 Months Ended
	Aug. 01, 2021	Aug. 02, 2020	Jul. 28, 2019
Pension Plan, Defined Benefit [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Defined Benefit Plan, Benefit Obligation	$ 2,366	$ 2,345
Defined Benefit Plan, Service Cost	18	19	$ 21
Defined Benefit Plan, Interest Cost	41	65	82
Defined Benefit Plan, Benefit Obligation, Actuarial Loss (Gain)	(43)	237
Defined Benefit Plan, Benefits Paid	(152)	(148)
Defined Benefit Plan, Benefit Obligation, (Increase) Decrease for Settlement	(53)	(41)
Defined Benefit Plan, Benefit Obligation, Increase (Decrease) for Other Change	(2)	(3)
Defined Benefit Plan, Benefit Obligation, Divestiture	0	(105)
Defined Benefit Plan, Benefit Obligation, Foreign Currency Translation (Gain) Loss	11	(3)
Defined Benefit Plan, Benefit Obligation	2,186	2,366	2,345
Other Postretirement Benefit Plan, Defined Benefit [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Defined Benefit Plan, Benefit Obligation	244	235
Defined Benefit Plan, Service Cost	0	1	1
Defined Benefit Plan, Interest Cost	4	6	8
Defined Benefit Plan, Benefit Obligation, Actuarial Loss (Gain)	(6)	23
Defined Benefit Plan, Benefits Paid	(20)	(21)
Defined Benefit Plan, Benefit Obligation, (Increase) Decrease for Settlement	0	0
Defined Benefit Plan, Benefit Obligation, Increase (Decrease) for Other Change	0	0
Defined Benefit Plan, Benefit Obligation, Divestiture	0	0
Defined Benefit Plan, Benefit Obligation, Foreign Currency Translation (Gain) Loss	0	0
Defined Benefit Plan, Benefit Obligation	$ 222	$ 244	$ 235