Financing Receivables and Operating Leases (Schedule of Aging Analysis of Financing Receivables) (Details) - USD ($) $ in Millions	Jul. 29, 2017	Jul. 30, 2016
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	$ 1,733	$ 1,393
Current	7,983	7,210
FInancing receivables net of unearned income	9,716	8,603
Nonaccrual Financing Receivables	75	132
Impaired Financing Receivables	59	112
Past due 31 - 60 days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	550	353
Past due 61 -90 days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	185	186
Past due 91 or above days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	998	854
Leases Receivables
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	436	387
Current	2,203	2,711
FInancing receivables net of unearned income	2,639	3,098
Nonaccrual Financing Receivables	14	60
Impaired Financing Receivables	14	60
Leases Receivables | Past due 31 - 60 days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	160	111
Leases Receivables | Past due 61 -90 days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	60	25
Leases Receivables | Past due 91 or above days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	216	251
Loan Receivables
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	537	287
Current	4,023	3,159
FInancing receivables net of unearned income	4,560	3,446
Nonaccrual Financing Receivables	43	42
Impaired Financing Receivables	43	42
Loan Receivables | Past due 31 - 60 days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	230	83
Loan Receivables | Past due 61 -90 days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	48	37
Loan Receivables | Past due 91 or above days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	259	167
Financed Service Contracts
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	760	719
Current	1,757	1,340
FInancing receivables net of unearned income	2,517	2,059
Nonaccrual Financing Receivables	18	30
Impaired Financing Receivables	2	10
Financed Service Contracts | Past due 31 - 60 days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	160	159
Financed Service Contracts | Past due 61 -90 days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	77	124
Financed Service Contracts | Past due 91 or above days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	$ 523	$ 436