Financing Receivables and Operating Leases (Schedule of Aging Analysis of Financing Receivables) (Details) - USD ($) $ in Millions	Apr. 27, 2019	Jul. 28, 2018
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	$ 1,332	$ 1,185
Current	8,560	8,687
Total	9,892	9,872
Nonaccrual Financing Receivables	52	42
Impaired Financing Receivables	52	42
Past due 31-60 days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	262	314
Past due 61-90 days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	230	160
Past due 91 or above days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	840	711
Lease Receivables
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	229	254
Current	2,074	2,293
Total	2,303	2,547
Nonaccrual Financing Receivables	18	9
Impaired Financing Receivables	18	9
Lease Receivables | Past due 31-60 days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	79	72
Lease Receivables | Past due 61-90 days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	36	27
Lease Receivables | Past due 91 or above days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	114	155
Loan Receivables
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	444	411
Current	4,796	4,588
Total	5,240	4,999
Nonaccrual Financing Receivables	30	30
Impaired Financing Receivables	30	30
Loan Receivables | Past due 31-60 days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	108	104
Loan Receivables | Past due 61-90 days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	81	55
Loan Receivables | Past due 91 or above days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	255	252
Financed Service Contracts
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	659	520
Current	1,690	1,806
Total	2,349	2,326
Nonaccrual Financing Receivables	4	3
Impaired Financing Receivables	4	3
Financed Service Contracts | Past due 31-60 days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	75	138
Financed Service Contracts | Past due 61-90 days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	113	78
Financed Service Contracts | Past due 91 or above days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	$ 471	$ 304