Financing Receivables and Guarantees (Schedule Of Aging Analysis Of Financing Receivables) (Detail) (USD $) In Millions, unless otherwise specified	Jul. 28, 2012	Jul. 30, 2011
Financing Receivable, Recorded Investment, Past Due [Line Items]
31-60 Days Past Due	$ 250	$ 165
61-90 Days Past Due	145	75
Greater than 90 Days Past Due	576	438
Total Past Due	971	678
Current	6,655	6,288
Gross Receivables, Net of Unearned Income	7,626	6,966
Non-Accrual Financing Receivables	45	55
Impaired Financing Receivables	28	34
Lease Receivables
Financing Receivable, Recorded Investment, Past Due [Line Items]
31-60 Days Past Due	151	89
61-90 Days Past Due	69	35
Greater than 90 Days Past Due	173	152
Total Past Due	393	276
Current	2,786	2,585
Gross Receivables, Net of Unearned Income	3,179	2,861
Non-Accrual Financing Receivables	23	34
Impaired Financing Receivables	14	24
Loan Receivables
Financing Receivable, Recorded Investment, Past Due [Line Items]
31-60 Days Past Due	10	8
61-90 Days Past Due	8	7
Greater than 90 Days Past Due	11	21
Total Past Due	29	36
Current	1,767	1,432
Gross Receivables, Net of Unearned Income	1,796	1,468
Non-Accrual Financing Receivables	4	4
Impaired Financing Receivables	4	4
Financed Service Contracts & Other
Financing Receivable, Recorded Investment, Past Due [Line Items]
31-60 Days Past Due	89	68
61-90 Days Past Due	68	33
Greater than 90 Days Past Due	392	265
Total Past Due	549	366
Current	2,102	2,271
Gross Receivables, Net of Unearned Income	2,651	2,637
Non-Accrual Financing Receivables	18	17
Impaired Financing Receivables	$ 10	$ 6