Financing Receivables and Operating Leases (Schedule Of Financing Receivables Categorized By Internal Credit Risk Rating) (Details) - USD ($) $ in Millions	Oct. 24, 2015	Jul. 25, 2015
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	$ 8,696	$ 8,507
1 to 4
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	4,820	4,609
5 to 6
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	3,556	3,554
7 and Higher
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	320	344
Total
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	8,696	8,507
Lease Receivables | 1 to 4
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	1,670	1,688
Lease Receivables | 5 to 6
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	1,336	1,342
Lease Receivables | 7 and Higher
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	129	141
Lease Receivables | Total
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	3,135	3,171
Loan Receivables | 1 to 4
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	1,039	788
Loan Receivables | 5 to 6
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	783	823
Loan Receivables | 7 and Higher
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	141	152
Loan Receivables | Total
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	1,963	1,763
Financed Service Contracts and Other | 1 to 4
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	2,111	2,133
Financed Service Contracts and Other | 5 to 6
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	1,437	1,389
Financed Service Contracts and Other | 7 and Higher
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	50	51
Financed Service Contracts and Other | Total
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	$ 3,598	$ 3,573