Financing Receivables And Guarantees (Schedule Of Financing Receivables By Portfolio Segment Aging Analysis) (Detail) (USD $) In Millions, unless otherwise specified	Jan. 25, 2014	Jul. 27, 2013	Jan. 26, 2013
Financing Receivable, Recorded Investment, Past Due [Line Items]
31 to 60 Days Past Due	$ 293	$ 166
61 to 90 Days Past Due	111	99
Greater Than 90 Days Past Due	400	527
Total Past Due	804	792
Class Of Financing Receivable Current	7,214	7,500
Gross Financing Receivable, Net of Unearned	8,018	8,292	8,092
Non-accrual financing receivables	86	56
Impaired Financing Receivables	77	42
Lease Receivables
Financing Receivable, Recorded Investment, Past Due [Line Items]
31 to 60 Days Past Due	86	85
61 to 90 Days Past Due	40	48
Greater Than 90 Days Past Due	162	124
Total Past Due	288	257
Class Of Financing Receivable Current	3,263	3,250
Gross Financing Receivable, Net of Unearned	3,551	3,507	3,444
Non-accrual financing receivables	59	27
Impaired Financing Receivables	53	22
Loan Receivables
Financing Receivable, Recorded Investment, Past Due [Line Items]
31 to 60 Days Past Due	6	6
61 to 90 Days Past Due	5	3
Greater Than 90 Days Past Due	11	11
Total Past Due	22	20
Class Of Financing Receivable Current	1,638	1,629
Gross Financing Receivable, Net of Unearned	1,660	1,649	1,785
Non-accrual financing receivables	16	11
Impaired Financing Receivables	16	9
Financed Service Contracts And Other
Financing Receivable, Recorded Investment, Past Due [Line Items]
31 to 60 Days Past Due	201	75
61 to 90 Days Past Due	66	48
Greater Than 90 Days Past Due	227	392
Total Past Due	494	515
Class Of Financing Receivable Current	2,313	2,621
Gross Financing Receivable, Net of Unearned	2,807	3,136	2,863
Non-accrual financing receivables	11	18
Impaired Financing Receivables	$ 8	$ 11