Financing Receivables and Operating Leases (Schedule Of Financing Receivables Categorized By Internal Credit Risk Rating) (Details) (USD $) In Millions, unless otherwise specified	Apr. 25, 2015		Jul. 26, 2014	Apr. 26, 2014
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	$ 7,887		$ 8,187
Total financing receivables before allowance for credit loss	8,113	[1]	8,420	7,968	[1]
1 to 4
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	3,995		4,312
5 to 6
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	3,558		3,498
7 and Higher
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	334		377
Total
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	7,887		8,187
Lease Receivables
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	3,086		3,294
Total financing receivables before allowance for credit loss	3,312	[1]		3,537	[1]
Lease Receivables | 1 to 4
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	1,590		1,615
Lease Receivables | 5 to 6
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	1,371		1,538
Lease Receivables | 7 and Higher
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	125		141
Lease Receivables | Total
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	3,086		3,294
Loan Receivables
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	1,720		1,683
Total financing receivables before allowance for credit loss	1,720	[1]		1,621	[1]
Loan Receivables | 1 to 4
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	755		953
Loan Receivables | 5 to 6
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	816		593
Loan Receivables | 7 and Higher
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	149		137
Loan Receivables | Total
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	1,720		1,683
Financed Service Contracts and Other
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	3,081		3,210
Total financing receivables before allowance for credit loss	3,081	[1]		2,810	[1]
Financed Service Contracts and Other | 1 to 4
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	1,650		1,744
Financed Service Contracts and Other | 5 to 6
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	1,371		1,367
Financed Service Contracts and Other | 7 and Higher
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	60		99
Financed Service Contracts and Other | Total
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	$ 3,081		$ 3,210

[1] Total financing receivables before allowance for credit loss.