Financing Receivables - Schedule of Aging Analysis of Financing Receivables (Details) - USD ($) $ in Millions	Jan. 25, 2020	Jul. 27, 2019
Financing Receivable, Past Due [Line Items]
Total Past Due	$ 1,079	$ 1,643
Current	8,517	8,394
Total	9,596	10,037
Nonaccrual Financing Receivables	102	47
Impaired Financing Receivables	102	47
Past due 31-60 days
Financing Receivable, Past Due [Line Items]
Total Past Due	269	503
Past due 61-90 days
Financing Receivable, Past Due [Line Items]
Total Past Due	110	240
Past due 91 or above days
Financing Receivable, Past Due [Line Items]
Total Past Due	700	900
Lease Receivables
Financing Receivable, Past Due [Line Items]
Total Past Due	264	434
Current	1,853	1,796
Total	2,117	2,230
Nonaccrual Financing Receivables	22	13
Impaired Financing Receivables	22	13
Lease Receivables | Past due 31-60 days
Financing Receivable, Past Due [Line Items]
Total Past Due	58	101
Lease Receivables | Past due 61-90 days
Financing Receivable, Past Due [Line Items]
Total Past Due	34	42
Lease Receivables | Past due 91 or above days
Financing Receivable, Past Due [Line Items]
Total Past Due	172	291
Loan Receivables
Financing Receivable, Past Due [Line Items]
Total Past Due	379	662
Current	4,918	4,776
Total	5,297	5,438
Nonaccrual Financing Receivables	78	31
Impaired Financing Receivables	78	31
Loan Receivables | Past due 31-60 days
Financing Receivable, Past Due [Line Items]
Total Past Due	129	257
Loan Receivables | Past due 61-90 days
Financing Receivable, Past Due [Line Items]
Total Past Due	31	67
Loan Receivables | Past due 91 or above days
Financing Receivable, Past Due [Line Items]
Total Past Due	219	338
Financed Service Contracts
Financing Receivable, Past Due [Line Items]
Total Past Due	436	547
Current	1,746	1,822
Total	2,182	2,369
Nonaccrual Financing Receivables	2	3
Impaired Financing Receivables	2	3
Financed Service Contracts | Past due 31-60 days
Financing Receivable, Past Due [Line Items]
Total Past Due	82	145
Financed Service Contracts | Past due 61-90 days
Financing Receivable, Past Due [Line Items]
Total Past Due	45	131
Financed Service Contracts | Past due 91 or above days
Financing Receivable, Past Due [Line Items]
Total Past Due	$ 309	$ 271