Financing Receivables and Operating Leases (Schedule Of Financing Receivables Categorized By Internal Credit Risk Rating) (Details) - USD ($) $ in Millions	Oct. 29, 2016	Jul. 30, 2016
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	$ 9,514	$ 8,603
1 to 4
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	5,631	4,766
5 to 6
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	3,582	3,532
7 and Higher
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	301	305
Total
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	9,514	8,603
Lease Receivables | 1 to 4
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	1,652	1,703
Lease Receivables | 5 to 6
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	1,293	1,294
Lease Receivables | 7 and Higher
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	94	101
Lease Receivables | Total
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	3,039	3,098
Loan Receivables | 1 to 4
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	1,081	986
Loan Receivables | 5 to 6
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	976	967
Loan Receivables | 7 and Higher
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	179	182
Loan Receivables | Total
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	2,236	2,135
Financed Service Contracts and Other | 1 to 4
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	2,898	2,077
Financed Service Contracts and Other | 5 to 6
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	1,313	1,271
Financed Service Contracts and Other | 7 and Higher
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	28	22
Financed Service Contracts and Other | Total
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	$ 4,239	$ 3,370