Financing Receivables and Operating Leases (Additional Information) (Details) - USD ($) $ in Millions		12 Months Ended
		Jul. 25, 2015	Jul. 26, 2014	Jul. 27, 2013
Financing Receivables And Guarantees [Line Items]
Average lease term (in years)		4 years
Deferred revenue:		$ 15,183	$ 14,142
Financing receivable, allowance for credit loss and deferred revenue		2,253	2,220
Total financing receivables before allowance for credit loss	[1]	$ 8,731	8,420	$ 8,292
Threshold for past due receivables (in days)		31 days
Unbilled or current financing receivables included in greater than 91 days plus past due		$ 496	334
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		70	78
Minimum future rentals from operating leases (per year amount in Fiscal 2016)		200
Minimum future rental from operating leases (per year amount in Fiscal 2017)		100
Lease Receivables
Financing Receivables And Guarantees [Line Items]
Total financing receivables before allowance for credit loss	[1]	3,395	3,527	3,507
Loan Receivables
Financing Receivables And Guarantees [Line Items]
Total financing receivables before allowance for credit loss	[1]	1,763	1,683	1,649
Financed Service Contracts and Other
Financing Receivables And Guarantees [Line Items]
Deferred revenue:		1,853	1,843
Total financing receivables before allowance for credit loss	[1]	$ 3,573	$ 3,210	$ 3,136
Minimum
Financing Receivables And Guarantees [Line Items]
Financed service contracts term (in years)		1 year
Minimum | Financed Service Contracts and Other
Financing Receivables And Guarantees [Line Items]
Financed service contracts term (in years)		1 year
Minimum | Pass
Financing Receivables And Guarantees [Line Items]
Financing credit risk rating-investment-lowest		1
Minimum | Special Mention
Financing Receivables And Guarantees [Line Items]
Financing credit risk rating-investment-lowest		5
Minimum | Substandard
Financing Receivables And Guarantees [Line Items]
Financing credit risk rating-investment-lowest		7
Maximum
Financing Receivables And Guarantees [Line Items]
Loan receivables term (in years)		3 years
Financed service contracts term (in years)		3 years
Minimum future rentals from operating leases (per year amount in Fiscal 2018)		$ 100
Minimum future rentals from operating leases (per year amount in Fiscal 2019)		100
Minimum future rentals from operating leases (per year amount in Fiscal 2020)		$ 100
Maximum | Financed Service Contracts and Other
Financing Receivables And Guarantees [Line Items]
Financed service contracts term (in years)		3 years
Maximum | Pass
Financing Receivables And Guarantees [Line Items]
Financing credit risk rating-investment-lowest		4
Maximum | Special Mention
Financing Receivables And Guarantees [Line Items]
Financing credit risk rating-investment-lowest		6

[1] Total financing receivables before allowance for credit loss.