Pension And Postretirement Benefits (Amounts Recognized in Consolidated Balance Sheets) (Details) - USD ($) $ in Millions	Aug. 01, 2021	Aug. 02, 2020
Defined Benefit Plan Disclosure [Line Items]
Assets for Plan Benefits, Defined Benefit Plan	$ 190	$ 10
Pension Plan, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Assets for Plan Benefits, Defined Benefit Plan	190	10
Liability, Defined Benefit Plan, Current	14	14
Liability, Defined Benefit Plan, Noncurrent	142	242
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position	34	(246)
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]
Assets for Plan Benefits, Defined Benefit Plan	0	0
Liability, Defined Benefit Plan, Current	23	24
Liability, Defined Benefit Plan, Noncurrent	199	220
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position	(222)	(244)
Defined Benefit Plan, Accumulated Other Comprehensive (Income) Loss, Prior Service Cost (Credit), before Tax	$ 5	$ 10