Pension And Postretirement Benefits (Schedule Of Components of Benefit Expense) (Details) - USD ($) $ in Millions	3 Months Ended
	Oct. 30, 2016	Nov. 01, 2015
Pension Plan, Defined Benefit [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Defined Benefit Plan, Service Cost	$ 6	$ 7
Defined Benefit Plan, Interest Cost	22	25
Expected return on plan assets	(36)	(39)
Amortization of Prior Service Cost (Credit)	0	0
Defined Benefit Plan, Actuarial Gain (Loss)	0	136
Defined Benefit Plan, Net Periodic Benefit Cost	(8)	129
Other Postretirement Benefit Plan [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Defined Benefit Plan, Service Cost	0	0
Defined Benefit Plan, Interest Cost	3	4
Expected return on plan assets	0	0
Amortization of Prior Service Cost (Credit)	(6)	0
Defined Benefit Plan, Actuarial Gain (Loss)	0	0
Defined Benefit Plan, Net Periodic Benefit Cost	$ (3)	$ 4