Financing Receivables and Guarantees (Schedule Of Aging Analysis Of Financing Receivables) (Detail) (USD $) In Millions, unless otherwise specified	Jul. 27, 2013	Jul. 28, 2012	Jul. 30, 2011
Financing Receivable, Recorded Investment, Past Due [Line Items]
31 to 60 Day Past Due	$ 166	$ 250
61 to 90 Days Past Due	99	145
Greater Than 90 Days Past Due	527	576
Total Past Due	792	971
Current	7,500	6,655
Gross Receivables, Net of Unearned Income	8,292	7,626	6,966
Nonaccrual Financing Receivables	56	45
Impaired Financing Receivables	42	28
Lease Receivables
Financing Receivable, Recorded Investment, Past Due [Line Items]
31 to 60 Day Past Due	85	151
61 to 90 Days Past Due	48	69
Greater Than 90 Days Past Due	124	173
Total Past Due	257	393
Current	3,250	2,786
Gross Receivables, Net of Unearned Income	3,507	3,179	2,861
Nonaccrual Financing Receivables	27	23
Impaired Financing Receivables	22	14
Loan Receivables
Financing Receivable, Recorded Investment, Past Due [Line Items]
31 to 60 Day Past Due	6	10
61 to 90 Days Past Due	3	8
Greater Than 90 Days Past Due	11	11
Total Past Due	20	29
Current	1,629	1,767
Gross Receivables, Net of Unearned Income	1,649	1,796	1,468
Nonaccrual Financing Receivables	11	4
Impaired Financing Receivables	9	4
Financed Service Contracts & Other
Financing Receivable, Recorded Investment, Past Due [Line Items]
31 to 60 Day Past Due	75	89
61 to 90 Days Past Due	48	68
Greater Than 90 Days Past Due	392	392
Total Past Due	515	549
Current	2,621	2,102
Gross Receivables, Net of Unearned Income	3,136	2,651	2,637
Nonaccrual Financing Receivables	18	18
Impaired Financing Receivables	$ 11	$ 10