Financing Receivables - Schedule of Aging Analysis of Financing Receivables (Details) - USD ($) $ in Millions	Apr. 25, 2020	Jul. 27, 2019
Financing Receivable, Past Due [Line Items]
Total Past Due	$ 865	$ 1,643
Current	8,609	8,394
Total	9,474	10,037
Nonaccrual Financing Receivables	81	47
Impaired Financing Receivables	81	47
Past due 31-60 days
Financing Receivable, Past Due [Line Items]
Total Past Due	304	503
Past due 61-90 days
Financing Receivable, Past Due [Line Items]
Total Past Due	123	240
Past due 91 or above days
Financing Receivable, Past Due [Line Items]
Total Past Due	438	900
Lease Receivables
Financing Receivable, Past Due [Line Items]
Total Past Due	218	434
Current	1,830	1,796
Total	2,048	2,230
Nonaccrual Financing Receivables	18	13
Impaired Financing Receivables	18	13
Lease Receivables | Past due 31-60 days
Financing Receivable, Past Due [Line Items]
Total Past Due	81	101
Lease Receivables | Past due 61-90 days
Financing Receivable, Past Due [Line Items]
Total Past Due	18	42
Lease Receivables | Past due 91 or above days
Financing Receivable, Past Due [Line Items]
Total Past Due	119	291
Loan Receivables
Financing Receivable, Past Due [Line Items]
Total Past Due	328	662
Current	4,931	4,776
Total	5,259	5,438
Nonaccrual Financing Receivables	60	31
Impaired Financing Receivables	60	31
Loan Receivables | Past due 31-60 days
Financing Receivable, Past Due [Line Items]
Total Past Due	146	257
Loan Receivables | Past due 61-90 days
Financing Receivable, Past Due [Line Items]
Total Past Due	43	67
Loan Receivables | Past due 91 or above days
Financing Receivable, Past Due [Line Items]
Total Past Due	139	338
Financed Service Contracts
Financing Receivable, Past Due [Line Items]
Total Past Due	319	547
Current	1,848	1,822
Total	2,167	2,369
Nonaccrual Financing Receivables	3	3
Impaired Financing Receivables	3	3
Financed Service Contracts | Past due 31-60 days
Financing Receivable, Past Due [Line Items]
Total Past Due	77	145
Financed Service Contracts | Past due 61-90 days
Financing Receivable, Past Due [Line Items]
Total Past Due	62	131
Financed Service Contracts | Past due 91 or above days
Financing Receivable, Past Due [Line Items]
Total Past Due	$ 180	$ 271