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				9 Months Ended
	Apr. 25, 2015		Apr. 26, 2014		Apr. 25, 2015		Apr. 26, 2014		Jul. 26, 2014
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for credit loss as of	$ 375		$ 374		$ 349		$ 344
Provisions	(11)		(18)		31		14
Recoveries, net			2				3
Write-offs, net	(1)				(5)
Foreign exchange and other	(4)		2		(16)		(1)
Allowance for credit loss as of	359		360		359		360
Total financing receivables before allowance for credit loss	8,113	[1]	7,968	[1]	8,113	[1]	7,968	[1]	8,420
Lease Receivables
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for credit loss as of	250		254		233		238
Provisions	(4)		(6)		25		9
Write-offs, net	(1)		(1)		(6)		0
Foreign exchange and other	(3)		2		(10)		2
Allowance for credit loss as of	242		249		242		249
Total financing receivables before allowance for credit loss	3,312	[1]	3,537	[1]	3,312	[1]	3,537	[1]
Loan Receivables
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for credit loss as of	85		98		98		86
Provisions	(5)		(10)		(15)		5
Recoveries, net	0		4		1		4
Foreign exchange and other	0		0		(4)		(3)
Allowance for credit loss as of	80		92		80		92
Total financing receivables before allowance for credit loss	1,720	[1]	1,621	[1]	1,720	[1]	1,621	[1]
Financed Service Contracts and Other
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for credit loss as of	40		22		18		20
Provisions	(2)		(2)		21		0
Write-offs, net	0		(1)		0		(1)
Foreign exchange and other	(1)		0		(2)		0
Allowance for credit loss as of	37		19		37		19
Total financing receivables before allowance for credit loss	$ 3,081	[1]	$ 2,810	[1]	$ 3,081	[1]	$ 2,810	[1]

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