Financing Receivables and Operating Leases (Schedule Of Aging Analysis Of Financing Receivables) (Details) - USD ($) $ in Millions	Apr. 30, 2016	Jul. 25, 2015
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Amount	$ 837	$ 1,313
Current	7,957	7,194
Total	8,794	8,507
Nonaccrual Financing Receivables	150	134
Impaired Financing Receivables	128	114
Past due 31-60 days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Amount	171	507
Past due 61-90 days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Amount	170	182
Past due 91 or above days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Amount	496	624
Lease Receivables
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Amount	266	302
Current	2,801	2,869
Total	3,067	3,171
Nonaccrual Financing Receivables	67	73
Impaired Financing Receivables	65	73
Lease Receivables | Past due 31-60 days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Amount	41	90
Lease Receivables | Past due 61-90 days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Amount	44	27
Lease Receivables | Past due 91 or above days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Amount	181	185
Loan Receivables
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Amount	140	49
Current	2,083	1,714
Total	2,223	1,763
Nonaccrual Financing Receivables	47	32
Impaired Financing Receivables	47	32
Loan Receivables | Past due 31-60 days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Amount	51	21
Loan Receivables | Past due 61-90 days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Amount	11	3
Loan Receivables | Past due 91 or above days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Amount	78	25
Financed Service Contracts and Other
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Amount	431	962
Current	3,073	2,611
Total	3,504	3,573
Nonaccrual Financing Receivables	36	29
Impaired Financing Receivables	16	9
Financed Service Contracts and Other | Past due 31-60 days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Amount	79	396
Financed Service Contracts and Other | Past due 61-90 days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Amount	115	152
Financed Service Contracts and Other | Past due 91 or above days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Amount	$ 237	$ 414