Financing Receivables and Operating Leases (Schedule Of Financing Receivables Categorized By Internal Credit Risk Rating) (Details) - USD ($) $ in Millions	Oct. 28, 2017	Jul. 29, 2017
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	$ 10,036	$ 9,716
1 to 4
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	5,964	5,866
5 to 6
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	3,819	3,599
7 and Higher
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	253	251
Total
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	10,036	9,716
Lease Receivables | 1 to 4
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	1,320	1,408
Lease Receivables | 5 to 6
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	1,337	1,181
Lease Receivables | 7 and Higher
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	48	50
Lease Receivables | Total
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	2,705	2,639
Loan Receivables | 1 to 4
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	2,988	2,865
Loan Receivables | 5 to 6
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	1,571	1,516
Loan Receivables | 7 and Higher
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	189	179
Loan Receivables | Total
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	4,748	4,560
Financed Service Contracts | 1 to 4
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	1,656	1,593
Financed Service Contracts | 5 to 6
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	911	902
Financed Service Contracts | 7 and Higher
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	16	22
Financed Service Contracts | Total
Financing Receivable, Recorded Investment [Line Items]
Gross receivables less unearned income	$ 2,583	$ 2,517