Pension And Postretirement Benefits (Schedule Of Components of Benefit Expense) (Details) - USD ($) $ in Millions	12 Months Ended
	Aug. 02, 2015	Aug. 03, 2014	Jul. 28, 2013
Pension Plan, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Service Cost	$ 28	$ 42	$ 57
Defined Benefit Plan, Interest Cost	105	115	108
Expected return on plan assets	(173)	(176)	(177)
Amortization of Prior Service Cost (Credit)	(1)	(1)	(1)
Recognized net actuarial loss	84	76	108
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Curtailments	1	0	3
Defined Benefit Plan, Recognized Net Gain Loss Due to Settlements	0	22	0
Defined Benefit Plan, Net Periodic Benefit Cost	44	78	98
Pension Plan, Defined Benefit [Member] | Corporate, Non-Segment [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Recognized Net Gain Loss Due to Settlements		22
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Service Cost	2	2	3
Defined Benefit Plan, Interest Cost	15	17	15
Amortization of Prior Service Cost (Credit)	(1)	(1)	(1)
Recognized net actuarial loss	14	13	15
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Curtailments	6	0	0
Defined Benefit Plan, Net Periodic Benefit Cost	$ 36	$ 31	$ 32