Financing Receivables - Schedule of Aging Analysis of Financing Receivables (Details) - USD ($) $ in Millions	Jul. 25, 2020	Jul. 27, 2019
Financing Receivable, Past Due [Line Items]
Total Past Due	$ 677	$ 1,643
Current	10,103	8,394
Total	10,780	10,037
Nonaccrual Financing Receivables	112	47
Impaired Financing Receivables	112	47
Past due 31 - 60 days
Financing Receivable, Past Due [Line Items]
Total Past Due	227	503
Past due 61 -90 days
Financing Receivable, Past Due [Line Items]
Total Past Due	200	240
Past due 91 or above days
Financing Receivable, Past Due [Line Items]
Total Past Due	250	900
Lease Receivables
Financing Receivable, Past Due [Line Items]
Total Past Due	124	434
Current	1,889	1,796
Total	2,013	2,230
Nonaccrual Financing Receivables	43	13
Impaired Financing Receivables	43	13
Lease Receivables | Past due 31 - 60 days
Financing Receivable, Past Due [Line Items]
Total Past Due	29	101
Lease Receivables | Past due 61 -90 days
Financing Receivable, Past Due [Line Items]
Total Past Due	47	42
Lease Receivables | Past due 91 or above days
Financing Receivable, Past Due [Line Items]
Total Past Due	48	291
Loan Receivables
Financing Receivable, Past Due [Line Items]
Total Past Due	285	662
Current	5,652	4,776
Total	5,937	5,438
Nonaccrual Financing Receivables	65	31
Impaired Financing Receivables	65	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	78	67
Loan Receivables | Past due 91 or above days
Financing Receivable, Past Due [Line Items]
Total Past Due	78	338
Financed service contracts
Financing Receivable, Past Due [Line Items]
Total Past Due	268	547
Current	2,562	1,822
Total	2,830	2,369
Nonaccrual Financing Receivables	4	3
Impaired Financing Receivables	4	3
Financed service contracts | Past due 31 - 60 days
Financing Receivable, Past Due [Line Items]
Total Past Due	69	145
Financed service contracts | Past due 61 -90 days
Financing Receivable, Past Due [Line Items]
Total Past Due	75	131
Financed service contracts | Past due 91 or above days
Financing Receivable, Past Due [Line Items]
Total Past Due	$ 124	$ 271