Financing Receivables and Operating Leases (Additional Information) (Details) $ in Millions	3 Months Ended
	Oct. 29, 2016 USD ($) Rating	Jul. 30, 2016 USD ($)
Financing Receivables And Guarantees [Line Items]
Average lease term	4 years
Deferred revenue	$ 16,951	$ 16,472
Financing receivable, allowance for credit loss and deferred revenue	2,779	2,112
Total financing receivables before allowance for credit loss	$ 9,711	8,805
Threshold for past due receivables	31 days
Unbilled or current financing receivables included in greater than 91 days plus past due	$ 436	670
Financing receivable, 91 days past due and still accruing	$ 236	144
Investment credit risk ratings range lowest | Rating	1
Investment credit risk ratings range highest | Rating	10
Rating at or higher when receivables deemed impaired | Rating	8
Maximum
Financing Receivables And Guarantees [Line Items]
Loan receivables term	3 years
Financed Service Contracts and Other | Minimum
Financing Receivables And Guarantees [Line Items]
Financed service contracts term	1 year
Financed Service Contracts and Other | Maximum
Financing Receivables And Guarantees [Line Items]
Financed service contracts term	3 years
Financed Service Contracts and Other
Financing Receivables And Guarantees [Line Items]
Deferred revenue	$ 2,371	$ 1,716