Pension And Postretirement Benefits (Schedule Of Components of Benefit Expense) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Apr. 28, 2019	Apr. 29, 2018	Apr. 28, 2019	Apr. 29, 2018
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Defined Benefit Plan, settlement charges	$ 28	$ 0	$ 28	$ 0
Pension Plan, Defined Benefit [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Defined Benefit Plan, Service Cost	5	6	16	18
Defined Benefit Plan, Interest Cost	21	19	62	56
Expected return on plan assets	(36)	(36)	(107)	(108)
Defined Benefit Plan, Amortization of Prior Service Cost (Credit)	0	0	0	0
Defined Benefit Plan, Cost of Providing Special and Contractual Termination Benefits	0	0	0	2
Defined Benefit Plan, settlement charges	28	0	28	0
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	18	(11)	(1)	(32)
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Defined Benefit Plan, Service Cost	1	1	1	1
Defined Benefit Plan, Interest Cost	2	1	6	5
Expected return on plan assets	0	0	0	0
Defined Benefit Plan, Amortization of Prior Service Cost (Credit)	(8)	(7)	(22)	(20)
Defined Benefit Plan, Cost of Providing Special and Contractual Termination Benefits	0	0	0	0
Defined Benefit Plan, settlement charges	0	0	0	0
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	$ (5)	$ (5)	$ (15)	$ (14)