Financing Receivables and Operating Leases (Additional Information) (Details) (USD $)	3 Months Ended
	Oct. 25, 2014 Rating		Jul. 26, 2014	Oct. 26, 2013
Financing Receivables And Guarantees [Line Items]
Average lease term (in years)	4 years
Loan receivables term (in years)	3 years
Deferred revenue:	$ 13,744,000,000		$ 14,142,000,000
Financing receivable, allowance for credit loss and deferred revenue	2,054,000,000		2,220,000,000
Total financing receivables before allowance for credit loss	8,324,000,000	[1]	8,420,000,000	8,375,000,000	[1]
Threshold for past due receivables (in days)	31 days
Unbilled or current financing receivables included in greater than 91 days plus past due	661,000,000		296,000,000
Financing Receivable, 90 Days Past Due and Still Accruing	111,000,000		78,000,000
Operating Leases, Future Minimum Payments, Remainder of Fiscal Year	200,000,000
Minimum future rental from operating leases (per year amount in Fiscal 2016)	100,000,000
Investment Credit Risk Ratings Range Lowest	1
Investment Credit Risk Ratings Range Highest	10
Rating at or higher when receivables deemed impaired	8
Lease Receivables
Financing Receivables And Guarantees [Line Items]
Total financing receivables before allowance for credit loss	3,509,000,000	[1]		3,549,000,000	[1]
Loan Receivables
Financing Receivables And Guarantees [Line Items]
Total financing receivables before allowance for credit loss	1,744,000,000	[1]		1,808,000,000	[1]
Financed Service Contracts and Other
Financing Receivables And Guarantees [Line Items]
Deferred revenue:	1,672,000,000		1,843,000,000
Total financing receivables before allowance for credit loss	3,071,000,000	[1]		3,018,000,000	[1]
Minimum | Financed Service Contracts and Other
Financing Receivables And Guarantees [Line Items]
Financed service contracts term (in years)	1 year
Minimum | Investment-grade ratings
Financing Receivables And Guarantees [Line Items]
Financing credit risk rating-investment-lowest	1
Minimum | Non-investment grade ratings
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]
Minimum future rentals from operating leases (per year amount in Fiscal 2018)	100,000,000
Operating Leases, Future Minimum Payments, Due in Five Years	100,000,000
Operating Leases, Future Minimum Payments Receivable, in Three Years	$ 100,000,000
Maximum | Financed Service Contracts and Other
Financing Receivables And Guarantees [Line Items]
Financed service contracts term (in years)	3 years
Maximum | Investment-grade ratings
Financing Receivables And Guarantees [Line Items]
Financing credit risk rating-investment-lowest	4
Maximum | Non-investment grade ratings
Financing Receivables And Guarantees [Line Items]
Financing credit risk rating-investment-lowest	6

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