Financing Receivables - Schedule of Aging Analysis of Financing Receivables (Details) - USD ($) $ in Millions	Oct. 24, 2020	Jul. 25, 2020
Financing Receivable, Past Due [Line Items]
Total Past Due	$ 687	$ 677
Current	9,969	10,103
Gross	10,656	10,780
120+ Still Accruing	47	67
Nonaccrual Financing Receivables	97	112
Impaired Financing Receivables	97	112
Past due 31-60 days
Financing Receivable, Past Due [Line Items]
Total Past Due	235	227
Past due 61-90 days
Financing Receivable, Past Due [Line Items]
Total Past Due	87	200
Past due 91 or above days
Financing Receivable, Past Due [Line Items]
Total Past Due	365	250
Lease Receivables
Financing Receivable, Past Due [Line Items]
Total Past Due	169	124
Current	1,789	1,889
Gross	1,958	2,013
120+ Still Accruing	4
Nonaccrual Financing Receivables	39	43
Impaired Financing Receivables	39	43
Lease Receivables | Past due 31-60 days
Financing Receivable, Past Due [Line Items]
Total Past Due	45	29
Lease Receivables | Past due 61-90 days
Financing Receivable, Past Due [Line Items]
Total Past Due	21	47
Lease Receivables | Past due 91 or above days
Financing Receivable, Past Due [Line Items]
Total Past Due	103	48
Loan Receivables
Financing Receivable, Past Due [Line Items]
Total Past Due	225	285
Current	5,729	5,652
Gross	5,954	5,937
120+ Still Accruing	10
Nonaccrual Financing Receivables	54	65
Impaired Financing Receivables	54	65
Loan Receivables | Past due 31-60 days
Financing Receivable, Past Due [Line Items]
Total Past Due	113	129
Loan Receivables | Past due 61-90 days
Financing Receivable, Past Due [Line Items]
Total Past Due	32	78
Loan Receivables | Past due 91 or above days
Financing Receivable, Past Due [Line Items]
Total Past Due	80	78
Financed Service Contracts
Financing Receivable, Past Due [Line Items]
Total Past Due	293	268
Current	2,451	2,562
Gross	2,744	2,830
120+ Still Accruing	33
Nonaccrual Financing Receivables	4	4
Impaired Financing Receivables	4	4
Financed Service Contracts | Past due 31-60 days
Financing Receivable, Past Due [Line Items]
Total Past Due	77	69
Financed Service Contracts | Past due 61-90 days
Financing Receivable, Past Due [Line Items]
Total Past Due	34	75
Financed Service Contracts | Past due 91 or above days
Financing Receivable, Past Due [Line Items]
Total Past Due	$ 182	$ 124