Pension And Postretirement Benefits (Amounts Recognized in Consolidated Balance Sheets) (Details) - USD ($) $ in Millions	Jul. 31, 2022	Aug. 01, 2021
Defined Benefit Plan Disclosure [Line Items]
Pensions	$ 146	$ 190
Pension Plan, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Pensions	146	190
Liability, Defined Benefit Plan, Current	13	14
Liability, Defined Benefit Plan, Noncurrent	107	142
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position	26	34
Defined Benefit Plan, Accumulated Other Comprehensive (Income) Loss, Prior Service Cost (Credit), before Tax	1	1
Other Postretirement Benefit Plan, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Pensions	0	0
Liability, Defined Benefit Plan, Current	19	23
Liability, Defined Benefit Plan, Noncurrent	153	199
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position	(172)	(222)
Defined Benefit Plan, Accumulated Other Comprehensive (Income) Loss, Prior Service Cost (Credit), before Tax	$ (4)	$ (5)