Pension And Postretirement Benefits (Schedule Of Components of Benefit Expense) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jan. 28, 2018	Jan. 29, 2017	Jan. 28, 2018	Jan. 29, 2017
Pension Plan, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Service Cost	$ 6	$ 7	$ 12	$ 13
Defined Benefit Plan, Interest Cost	18	21	37	43
Expected return on plan assets	(36)	(36)	(72)	(72)
Amortization of Prior Service Cost (Credit)	0	0	0	0
Defined Benefit Plan, Cost of Providing Special and Contractual Termination Benefits	2	0	2	0
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	(10)	(8)	(21)	(16)
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Service Cost	0	1	0	1
Defined Benefit Plan, Interest Cost	2	2	4	5
Expected return on plan assets	0	0	0	0
Amortization of Prior Service Cost (Credit)	(6)	(7)	(13)	(13)
Defined Benefit Plan, Cost of Providing Special and Contractual Termination Benefits	0	0	0	0
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	$ (4)	$ (4)	$ (9)	$ (7)