Pension And Postretirement Benefits (Schedule Of Components of Benefit Expense) (Details) - USD ($) $ in Millions	3 Months Ended
	Oct. 28, 2018	Oct. 29, 2017
Pension Plan, Defined Benefit [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Defined Benefit Plan, Service Cost	$ 5	$ 6
Defined Benefit Plan, Interest Cost	21	19
Expected return on plan assets	(36)	(36)
Defined Benefit Plan, Amortization of Prior Service Cost (Credit)	0	0
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	(10)	(11)
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Defined Benefit Plan, Service Cost	0	0
Defined Benefit Plan, Interest Cost	2	2
Expected return on plan assets	0	0
Defined Benefit Plan, Amortization of Prior Service Cost (Credit)	(7)	(7)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	$ (5)	$ (5)