Pension And Postretirement Benefits (Schedule Of Components of Benefit Expense) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Apr. 29, 2018	Apr. 30, 2017	Apr. 29, 2018	Apr. 30, 2017
Pension Plan, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Service Cost	$ 6	$ 6	$ 18	$ 19
Defined Benefit Plan, Interest Cost	19	21	56	64
Expected return on plan assets	(36)	(36)	(108)	(108)
Amortization of Prior Service Cost (Credit)	0	0	0	0
Defined Benefit Plan, Cost of Providing Special and Contractual Termination Benefits	0	0	2	0
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	(11)	(9)	(32)	(25)
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Service Cost	1	0	1	1
Defined Benefit Plan, Interest Cost	1	2	5	7
Expected return on plan assets	0	0	0	0
Amortization of Prior Service Cost (Credit)	(7)	(5)	(20)	(18)
Defined Benefit Plan, Cost of Providing Special and Contractual Termination Benefits	0	0	0	0
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	$ (5)	$ (3)	$ (14)	$ (10)