Financing Receivables And Guarantees (Schedule Of Financing Receivables Categorized By Internal Credit Risk Rating) (Detail) (USD $) In Millions, unless otherwise specified	Jan. 25, 2014	Jul. 27, 2013	Jan. 26, 2013
Financing Receivables And Guarantees [Line Items]
Gross Financing Receivable, Net of Unearned	$ 8,018	$ 8,292	$ 8,092
Rating One To Four [Member]
Financing Receivables And Guarantees [Line Items]
Gross Financing Receivable, Net of Unearned	4,139	4,399
Rating Five To Six [Member]
Financing Receivables And Guarantees [Line Items]
Gross Financing Receivable, Net of Unearned	3,300	3,400
Rating Seven And Higher [Member]
Financing Receivables And Guarantees [Line Items]
Gross Financing Receivable, Net of Unearned	333	242
Total Internal Credit Risk Rating [Member]
Financing Receivables And Guarantees [Line Items]
Gross Financing Receivable, Net of Unearned	7,772	8,041
Residual Value [Member]
Financing Receivables And Guarantees [Line Items]
Gross Financing Receivable, Net of Unearned	246	251
Lease Receivables
Financing Receivables And Guarantees [Line Items]
Gross Financing Receivable, Net of Unearned	3,551	3,507	3,444
Lease Receivables | Rating One To Four [Member]
Financing Receivables And Guarantees [Line Items]
Gross Financing Receivable, Net of Unearned	1,608	1,681
Lease Receivables | Rating Five To Six [Member]
Financing Receivables And Guarantees [Line Items]
Gross Financing Receivable, Net of Unearned	1,558	1,482
Lease Receivables | Rating Seven And Higher [Member]
Financing Receivables And Guarantees [Line Items]
Gross Financing Receivable, Net of Unearned	139	93
Lease Receivables | Total Internal Credit Risk Rating [Member]
Financing Receivables And Guarantees [Line Items]
Gross Financing Receivable, Net of Unearned	3,305	3,256
Lease Receivables | Residual Value [Member]
Financing Receivables And Guarantees [Line Items]
Gross Financing Receivable, Net of Unearned	246	251
Loan Receivables
Financing Receivables And Guarantees [Line Items]
Gross Financing Receivable, Net of Unearned	1,660	1,649	1,785
Loan Receivables | Rating One To Four [Member]
Financing Receivables And Guarantees [Line Items]
Gross Financing Receivable, Net of Unearned	890	842
Loan Receivables | Rating Five To Six [Member]
Financing Receivables And Guarantees [Line Items]
Gross Financing Receivable, Net of Unearned	682	777
Loan Receivables | Rating Seven And Higher [Member]
Financing Receivables And Guarantees [Line Items]
Gross Financing Receivable, Net of Unearned	88	30
Loan Receivables | Total Internal Credit Risk Rating [Member]
Financing Receivables And Guarantees [Line Items]
Gross Financing Receivable, Net of Unearned	1,660	1,649
Loan Receivables | Residual Value [Member]
Financing Receivables And Guarantees [Line Items]
Gross Financing Receivable, Net of Unearned	0	0
Financed Service Contracts And Other
Financing Receivables And Guarantees [Line Items]
Gross Financing Receivable, Net of Unearned	2,807	3,136	2,863
Financed Service Contracts And Other | Rating One To Four [Member]
Financing Receivables And Guarantees [Line Items]
Gross Financing Receivable, Net of Unearned	1,641	1,876
Financed Service Contracts And Other | Rating Five To Six [Member]
Financing Receivables And Guarantees [Line Items]
Gross Financing Receivable, Net of Unearned	1,060	1,141
Financed Service Contracts And Other | Rating Seven And Higher [Member]
Financing Receivables And Guarantees [Line Items]
Gross Financing Receivable, Net of Unearned	106	119
Financed Service Contracts And Other | Total Internal Credit Risk Rating [Member]
Financing Receivables And Guarantees [Line Items]
Gross Financing Receivable, Net of Unearned	2,807	3,136
Financed Service Contracts And Other | Residual Value [Member]
Financing Receivables And Guarantees [Line Items]
Gross Financing Receivable, Net of Unearned	$ 0	$ 0