Financing Receivables and Operating Leases (Schedule Of Aging Analysis Of Financing Receivables) (Details) - USD ($) $ in Millions	Oct. 28, 2017	Jul. 29, 2017
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	$ 1,751	$ 1,733
Current	8,285	7,983
Total	10,036	9,716
Nonaccrual Financing Receivables	71	75
Impaired Financing Receivables	60	59
Past due 31-60 days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	567	550
Past due 61-90 days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	351	185
Past due 91 or above days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	833	998
Lease Receivables
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	567	436
Current	2,138	2,203
Total	2,705	2,639
Nonaccrual Financing Receivables	14	14
Impaired Financing Receivables	14	14
Lease Receivables | Past due 31-60 days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	161	160
Lease Receivables | Past due 61-90 days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	86	60
Lease Receivables | Past due 91 or above days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	320	216
Loan Receivables
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	633	537
Current	4,115	4,023
Total	4,748	4,560
Nonaccrual Financing Receivables	44	43
Impaired Financing Receivables	44	43
Loan Receivables | Past due 31-60 days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	145	230
Loan Receivables | Past due 61-90 days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	81	48
Loan Receivables | Past due 91 or above days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	407	259
Financed Service Contracts
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	551	760
Current	2,032	1,757
Total	2,583	2,517
Nonaccrual Financing Receivables	13	18
Impaired Financing Receivables	2	2
Financed Service Contracts | Past due 31-60 days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	261	160
Financed Service Contracts | Past due 61-90 days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	184	77
Financed Service Contracts | Past due 91 or above days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	$ 106	$ 523