Pension And Postretirement Benefits (Schedule of Pension Plan Assets By Category) (Details) (Pension Plans, Defined Benefit [Member], USD $) In Millions, unless otherwise specified	Jul. 28, 2013	Jul. 29, 2012	Jul. 31, 2011
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	$ 2,275	$ 2,118	$ 2,059
Total Before Other Items [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	2,279	2,118
Total Before Other Items [Member] | Short Term Investment [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	78	70
Total Before Other Items [Member] | Municipal Bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	73	75
Total Before Other Items [Member] | Asset-backed Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	15	14
Total Before Other Items [Member] | Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	89	85
Total Before Other Items [Member] | Limited Partnerships [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	18	19
Total Before Other Items [Member] | Hedge Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	147	192
Total Before Other Items [Member] | Other Items To Reconcile To Fair Value Of Plan Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	(4)	0
Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	801	698
Fair Value, Inputs, Level 1 [Member] | Short Term Investment [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	36	44
Fair Value, Inputs, Level 1 [Member] | Municipal Bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Fair Value, Inputs, Level 1 [Member] | Asset-backed Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Fair Value, Inputs, Level 1 [Member] | Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	6	8
Fair Value, Inputs, Level 1 [Member] | Limited Partnerships [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Fair Value, Inputs, Level 1 [Member] | Hedge Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	1,430	1,385
Fair Value, Inputs, Level 2 [Member] | Short Term Investment [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	42	26
Fair Value, Inputs, Level 2 [Member] | Municipal Bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	73	75
Fair Value, Inputs, Level 2 [Member] | Asset-backed Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	15	14
Fair Value, Inputs, Level 2 [Member] | Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	83	61
Fair Value, Inputs, Level 2 [Member] | Limited Partnerships [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Fair Value, Inputs, Level 2 [Member] | Hedge Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	117	192
Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	48	35	39
Fair Value, Inputs, Level 3 [Member] | Short Term Investment [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Fair Value, Inputs, Level 3 [Member] | Municipal Bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Fair Value, Inputs, Level 3 [Member] | Asset-backed Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Fair Value, Inputs, Level 3 [Member] | Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	16	19
Fair Value, Inputs, Level 3 [Member] | Limited Partnerships [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	18	19	20
Fair Value, Inputs, Level 3 [Member] | Hedge Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	30	0	0
UNITED STATES | Total Before Other Items [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	401	357
UNITED STATES | Total Before Other Items [Member] | Domestic Corporate Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	420	444
UNITED STATES | Total Before Other Items [Member] | Domestic Government And Agency Bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	41	33
UNITED STATES | Fair Value, Inputs, Level 1 [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	401	357
UNITED STATES | Fair Value, Inputs, Level 1 [Member] | Domestic Corporate Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
UNITED STATES | Fair Value, Inputs, Level 1 [Member] | Domestic Government And Agency Bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
UNITED STATES | Fair Value, Inputs, Level 2 [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
UNITED STATES | Fair Value, Inputs, Level 2 [Member] | Domestic Corporate Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	420	444
UNITED STATES | Fair Value, Inputs, Level 2 [Member] | Domestic Government And Agency Bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	41	33
UNITED STATES | Fair Value, Inputs, Level 3 [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
UNITED STATES | Fair Value, Inputs, Level 3 [Member] | Domestic Corporate Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
UNITED STATES | Fair Value, Inputs, Level 3 [Member] | Domestic Government And Agency Bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Non-U.S. [Member] | Total Before Other Items [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	358	289
Non-U.S. [Member] | Total Before Other Items [Member] | Foreign Corporate Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	92	91
Non-U.S. [Member] | Total Before Other Items [Member] | Foreign Government And Agency Bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	37	30
Non-U.S. [Member] | Fair Value, Inputs, Level 1 [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	358	289
Non-U.S. [Member] | Fair Value, Inputs, Level 1 [Member] | Foreign Corporate Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Non-U.S. [Member] | Fair Value, Inputs, Level 1 [Member] | Foreign Government And Agency Bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Non-U.S. [Member] | Fair Value, Inputs, Level 2 [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Non-U.S. [Member] | Fair Value, Inputs, Level 2 [Member] | Foreign Corporate Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	92	91
Non-U.S. [Member] | Fair Value, Inputs, Level 2 [Member] | Foreign Government And Agency Bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	37	30
Non-U.S. [Member] | Fair Value, Inputs, Level 3 [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Non-U.S. [Member] | Fair Value, Inputs, Level 3 [Member] | Foreign Corporate Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Non-U.S. [Member] | Fair Value, Inputs, Level 3 [Member] | Foreign Government And Agency Bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Equity Funds [Member] | Total Before Other Items [Member] | Commingled Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	393	301
Equity Funds [Member] | Fair Value, Inputs, Level 1 [Member] | Commingled Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Equity Funds [Member] | Fair Value, Inputs, Level 2 [Member] | Commingled Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	393	301
Equity Funds [Member] | Fair Value, Inputs, Level 3 [Member] | Commingled Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Fixed Income Funds [Member] | Total Before Other Items [Member] | Commingled Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	29	37
Fixed Income Funds [Member] | Fair Value, Inputs, Level 1 [Member] | Commingled Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Fixed Income Funds [Member] | Fair Value, Inputs, Level 2 [Member] | Commingled Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	29	37
Fixed Income Funds [Member] | Fair Value, Inputs, Level 3 [Member] | Commingled Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Blended Funds [Member] | Total Before Other Items [Member] | Commingled Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	88	81
Blended Funds [Member] | Fair Value, Inputs, Level 1 [Member] | Commingled Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Blended Funds [Member] | Fair Value, Inputs, Level 2 [Member] | Commingled Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	88	81
Blended Funds [Member] | Fair Value, Inputs, Level 3 [Member] | Commingled Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	$ 0	$ 0