Financing Receivables and Operating Leases (Additional Information) (Details) $ in Millions	3 Months Ended	6 Months Ended
	Jan. 23, 2016 USD ($)	Jan. 23, 2016 USD ($) Rating	Jul. 25, 2015 USD ($)
Financing Receivables And Guarantees [Line Items]
Average lease term (in years)	4 years
Deferred revenue:	$ 15,185	$ 15,185	$ 15,183
Financing receivable, allowance for credit loss and deferred revenue	2,097	2,097	2,253
Total financing receivables before allowance for credit loss	$ 8,782	8,782	8,731
Threshold for past due receivables (in days)	31 days
Unbilled or current financing receivables included in greater than 91 days plus past due	$ 177	177	496
Financing Receivable, 90 Days Past Due and Still Accruing	187	187	70
Operating Leases, Future Minimum Payments, Remainder of Fiscal Year	100	100
Minimum future rental from operating leases (per year amount in Fiscal 2017)	$ 100	$ 100
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 (in years)	3 years
Minimum future rentals from operating leases (per year amount in Fiscal 2018)	$ 100	$ 100
Minimum future rentals from operating leases (per year amount in Fiscal 2019)	100	100
Minimum future rentals from operating leases (per year amount in Fiscal 2020)	$ 100	100
Financed Service Contracts and Other | Minimum
Financing Receivables And Guarantees [Line Items]
Financed service contracts term (in years)	1 year
Financed Service Contracts and Other | Maximum
Financing Receivables And Guarantees [Line Items]
Financed service contracts term (in years)	3 years
Investment-grade ratings | Minimum
Financing Receivables And Guarantees [Line Items]
Financing credit risk rating-investment-lowest	1
Investment-grade ratings | Maximum
Financing Receivables And Guarantees [Line Items]
Financing credit risk rating-investment-lowest	4
Non-investment grade ratings | Minimum
Financing Receivables And Guarantees [Line Items]
Financing credit risk rating-investment-lowest	5
Non-investment grade ratings | Maximum
Financing Receivables And Guarantees [Line Items]
Financing credit risk rating-investment-lowest	6
Substandard | Minimum
Financing Receivables And Guarantees [Line Items]
Financing credit risk rating-investment-lowest	7
Financed Service Contracts and Other
Financing Receivables And Guarantees [Line Items]
Deferred revenue:	$ 1,714	$ 1,714	$ 1,853