Financing Receivables and Operating Leases (Summary Of Allowances For Credit Loss And Related Financing Receivables) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Oct. 25, 2014		Oct. 26, 2013		Jul. 26, 2014
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for credit loss as of	$ 349		$ 344
Provisions	28		3
Recoveries (write-offs), net	(3)
Foreign exchange and other	(6)		3
Allowance for credit loss as of	368		350
Total financing receivables before allowance for credit loss	8,324	[1]	8,375	[1]	8,420
Lease Receivables
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for credit loss as of	233		238
Provisions	22		(3)
Recoveries (write-offs), net	(4)
Foreign exchange and other	(3)		2
Allowance for credit loss as of	248		237
Total financing receivables before allowance for credit loss	3,509	[1]	3,549	[1]
Loan Receivables
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for credit loss as of	98		86
Provisions	(13)		6
Recoveries (write-offs), net	1
Foreign exchange and other	(2)		1
Allowance for credit loss as of	84		93
Total financing receivables before allowance for credit loss	1,744	[1]	1,808	[1]
Financed Service Contracts and Other
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for credit loss as of	18		20
Provisions	19		0
Recoveries (write-offs), net	0
Foreign exchange and other	(1)		0
Allowance for credit loss as of	36		20
Total financing receivables before allowance for credit loss	$ 3,071	[1]	$ 3,018	[1]

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