Financing Receivables and Operating Leases (Schedule Of Financing Receivables Categorized By Internal Credit Risk Rating) (Details) - USD ($) $ in Millions	Apr. 29, 2017	Jul. 30, 2016
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	$ 9,401	$ 8,603
1 to 4
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	5,668	4,766
5 to 6
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	3,456	3,532
7 and Higher
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	277	305
Total
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	9,401	8,603
Lease Receivables | 1 to 4
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	1,404	1,703
Lease Receivables | 5 to 6
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	1,161	1,294
Lease Receivables | 7 and Higher
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	81	101
Lease Receivables | Total
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	2,646	3,098
Loan Receivables | 1 to 4
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	1,493	986
Loan Receivables | 5 to 6
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	990	967
Loan Receivables | 7 and Higher
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	176	182
Loan Receivables | Total
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	2,659	2,135
Financed Service Contracts and Other | 1 to 4
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	2,771	2,077
Financed Service Contracts and Other | 5 to 6
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	1,305	1,271
Financed Service Contracts and Other | 7 and Higher
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	20	22
Financed Service Contracts and Other | Total
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	$ 4,096	$ 3,370