Pension And Postretirement Benefits Pension And Postretirement Benefits (Schedule Of Changes In Fair Value Of Level 3 Investments) (Details) (Pension Plan, Defined Benefit [Member], USD $) In Millions, unless otherwise specified	12 Months Ended
	Aug. 03, 2014	Jul. 28, 2013
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	$ 2,275	$ 2,118
Defined Benefit Plan, Actual Return on Plan Assets	276	246
Defined Benefit Plan, Settlements, Plan Assets	43	0
Defined Benefit Plan, Fair Value of Plan Assets	2,364	2,275
Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	117	107
Hedge Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	181	147
Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	48	35
Defined Benefit Plan, Actual Return on Plan Assets	4	2
Defined Benefit Plan, Purchase of Plan Assets	25	30
Defined Benefit Plan, Sale of Plan Assets	(3)	(3)
Defined Benefit Plan, Settlements, Plan Assets	0	0
Defined Benefit Plan, Transfers Between Measurement Levels	0	(16)
Defined Benefit Plan, Fair Value of Plan Assets	74	48
Fair Value, Inputs, Level 3 [Member] | Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	18	35
Defined Benefit Plan, Actual Return on Plan Assets	2	2
Defined Benefit Plan, Purchase of Plan Assets	3	0
Defined Benefit Plan, Sale of Plan Assets	(3)	(3)
Defined Benefit Plan, Settlements, Plan Assets	0	0
Defined Benefit Plan, Transfers Between Measurement Levels	0	(16)
Defined Benefit Plan, Fair Value of Plan Assets	20	18
Fair Value, Inputs, Level 3 [Member] | Hedge Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	30	0
Defined Benefit Plan, Actual Return on Plan Assets	2	0
Defined Benefit Plan, Purchase of Plan Assets	22	30
Defined Benefit Plan, Sale of Plan Assets	0	0
Defined Benefit Plan, Settlements, Plan Assets	0	0
Defined Benefit Plan, Transfers Between Measurement Levels	0	0
Defined Benefit Plan, Fair Value of Plan Assets	$ 54	$ 30