Financing Receivables and Guarantees (Schedule Of Financing Receivables Categorized By Internal Credit Risk Rating) (Detail) (USD $) In Millions, unless otherwise specified	Jul. 27, 2013	Jul. 28, 2012	Jul. 30, 2011
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	$ 8,292	$ 7,626	$ 6,966
Lease Receivables
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	3,507	3,179	2,861
Loan Receivables
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	1,649	1,796	1,468
Financed Service Contracts & Other
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	3,136	2,651	2,637
Rating One To Four [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	4,399	3,915
Rating One To Four [Member] | Lease Receivables
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	1,681	1,532
Rating One To Four [Member] | Loan Receivables
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	842	831
Rating One To Four [Member] | Financed Service Contracts & Other
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	1,876	1,552
Rating Five To Six [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	3,400	3,293
Rating Five To Six [Member] | Lease Receivables
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	1,482	1,342
Rating Five To Six [Member] | Loan Receivables
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	777	921
Rating Five To Six [Member] | Financed Service Contracts & Other
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	1,141	1,030
Rating Seven And Higher [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	242	144
Rating Seven And Higher [Member] | Lease Receivables
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	93	31
Rating Seven And Higher [Member] | Loan Receivables
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	30	44
Rating Seven And Higher [Member] | Financed Service Contracts & Other
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	119	69
Total Internal Credit Risk Rating [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	8,041	7,352
Total Internal Credit Risk Rating [Member] | Lease Receivables
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	3,256	2,905
Total Internal Credit Risk Rating [Member] | Loan Receivables
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	1,649	1,796
Total Internal Credit Risk Rating [Member] | Financed Service Contracts & Other
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	3,136	2,651
Residual Value [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	251	274
Residual Value [Member] | Lease Receivables
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	$ 251	$ 274