Financing Receivables and Operating Leases (Schedule Of Aging Analysis Of Financing Receivables) (Details) - USD ($) $ in Millions	Jan. 28, 2017	Jul. 30, 2016
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	$ 1,353	$ 1,393
Current	7,994	7,210
Total	9,347	8,603
Nonaccrual Financing Receivables	151	132
Impaired Financing Receivables	131	112
Past due 31-60 days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	251	354
Past due 61-90 days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	304	186
Past due 91 or above days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	798	853
Lease Receivables
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	398	387
Current	2,415	2,711
Total	2,813	3,098
Nonaccrual Financing Receivables	66	60
Impaired Financing Receivables	66	60
Lease Receivables | Past due 31-60 days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	106	111
Lease Receivables | Past due 61-90 days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	55	25
Lease Receivables | Past due 91 or above days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	237	251
Loan Receivables
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	125	76
Current	2,244	2,059
Total	2,369	2,135
Nonaccrual Financing Receivables	56	42
Impaired Financing Receivables	56	42
Loan Receivables | Past due 31-60 days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	34	30
Loan Receivables | Past due 61-90 days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	24	9
Loan Receivables | Past due 91 or above days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	67	37
Financed Service Contracts and Other
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	830	930
Current	3,335	2,440
Total	4,165	3,370
Nonaccrual Financing Receivables	29	30
Impaired Financing Receivables	9	10
Financed Service Contracts and Other | Past due 31-60 days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	111	213
Financed Service Contracts and Other | Past due 61-90 days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	225	152
Financed Service Contracts and Other | Past due 91 or above days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	$ 494	$ 565