Financing Receivables And Guarantees (Schedule Of Financing Receivables Categorized By Internal Credit Risk Rating) (Detail) (USD $) In Millions, unless otherwise specified	Oct. 27, 2012	Jul. 28, 2012	Oct. 29, 2011
Loan Receivables [Member]
Financing Receivables And Guarantees [Line Items]
Capital Leases, Net Investment in Direct Financing Leases	$ 1,816	$ 1,796	$ 1,468
Financed Service Contracts And Other [Member]
Financing Receivables And Guarantees [Line Items]
Capital Leases, Net Investment in Direct Financing Leases	2,639	2,651	2,557
Rating One To Four [Member]
Financing Receivables And Guarantees [Line Items]
Capital Leases, Net Investment in Direct Financing Leases, Minimum Payments to be Received	4,078	3,915
Rating One To Four [Member] | Lease Receivables [Member]
Financing Receivables And Guarantees [Line Items]
Capital Leases, Net Investment in Direct Financing Leases, Minimum Payments to be Received	1,602	1,532
Rating One To Four [Member] | Loan Receivables [Member]
Financing Receivables And Guarantees [Line Items]
Capital Leases, Net Investment in Direct Financing Leases, Minimum Payments to be Received	945	831
Rating One To Four [Member] | Financed Service Contracts And Other [Member]
Financing Receivables And Guarantees [Line Items]
Capital Leases, Net Investment in Direct Financing Leases, Minimum Payments to be Received	1,531	1,552
Rating Five To Six [Member]
Financing Receivables And Guarantees [Line Items]
Capital Leases, Net Investment in Direct Financing Leases, Minimum Payments to be Received	3,261	3,293
Rating Five To Six [Member] | Lease Receivables [Member]
Financing Receivables And Guarantees [Line Items]
Capital Leases, Net Investment in Direct Financing Leases, Minimum Payments to be Received	1,417	1,342
Rating Five To Six [Member] | Loan Receivables [Member]
Financing Receivables And Guarantees [Line Items]
Capital Leases, Net Investment in Direct Financing Leases, Minimum Payments to be Received	834	921
Rating Five To Six [Member] | Financed Service Contracts And Other [Member]
Financing Receivables And Guarantees [Line Items]
Capital Leases, Net Investment in Direct Financing Leases, Minimum Payments to be Received	1,010	1,030
Rating Seven And Higher [Member]
Financing Receivables And Guarantees [Line Items]
Capital Leases, Net Investment in Direct Financing Leases, Minimum Payments to be Received	177	144
Rating Seven And Higher [Member] | Lease Receivables [Member]
Financing Receivables And Guarantees [Line Items]
Capital Leases, Net Investment in Direct Financing Leases, Minimum Payments to be Received	42	31
Rating Seven And Higher [Member] | Loan Receivables [Member]
Financing Receivables And Guarantees [Line Items]
Capital Leases, Net Investment in Direct Financing Leases, Minimum Payments to be Received	37	44
Rating Seven And Higher [Member] | Financed Service Contracts And Other [Member]
Financing Receivables And Guarantees [Line Items]
Capital Leases, Net Investment in Direct Financing Leases, Minimum Payments to be Received	98	69
Total Internal Credit Risk Rating [Member]
Financing Receivables And Guarantees [Line Items]
Capital Leases, Net Investment in Direct Financing Leases, Minimum Payments to be Received	7,516	7,352
Total Internal Credit Risk Rating [Member] | Lease Receivables [Member]
Financing Receivables And Guarantees [Line Items]
Capital Leases, Net Investment in Direct Financing Leases, Minimum Payments to be Received	3,061	2,905
Total Internal Credit Risk Rating [Member] | Loan Receivables [Member]
Financing Receivables And Guarantees [Line Items]
Capital Leases, Net Investment in Direct Financing Leases, Minimum Payments to be Received	1,816	1,796
Total Internal Credit Risk Rating [Member] | Financed Service Contracts And Other [Member]
Financing Receivables And Guarantees [Line Items]
Capital Leases, Net Investment in Direct Financing Leases, Minimum Payments to be Received	2,639	2,651
Residual Value [Member]
Financing Receivables And Guarantees [Line Items]
Capital Leases, Net Investment in Direct Financing Leases, Unguaranteed Residual Values of Leased Property	279	274
Residual Value [Member] | Lease Receivables [Member]
Financing Receivables And Guarantees [Line Items]
Capital Leases, Net Investment in Direct Financing Leases, Unguaranteed Residual Values of Leased Property	279	274
Residual Value [Member] | Loan Receivables [Member]
Financing Receivables And Guarantees [Line Items]
Capital Leases, Net Investment in Direct Financing Leases, Unguaranteed Residual Values of Leased Property	0	0
Residual Value [Member] | Financed Service Contracts And Other [Member]
Financing Receivables And Guarantees [Line Items]
Capital Leases, Net Investment in Direct Financing Leases, Unguaranteed Residual Values of Leased Property	0	0
Internal Credit Risk Rating [Member]
Financing Receivables And Guarantees [Line Items]
Capital Leases, Net Investment in Direct Financing Leases	7,795	7,626
Financing Receivable, Recorded Investment, Class of Financing Receivable [Domain] | Lease Receivables [Member]
Financing Receivables And Guarantees [Line Items]
Capital Leases, Net Investment in Direct Financing Leases	$ 3,340	$ 3,179	$ 2,849