Financing Receivables and Operating Leases (Summary Of Allowances For Credit Loss And Related Financing Receivables) (Details) - USD ($) $ in Millions		3 Months Ended
		Oct. 24, 2015		Oct. 25, 2014		Jul. 25, 2015
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for credit loss as of		$ 382		$ 349
Provisions		4		28
(Write-offs, net)		(7)		(3)
Foreign exchange and other		(1)		(6)
Allowance for credit loss as of		378		368
Total financing receivables before allowance for credit loss		8,921	[1]	8,324	[1]	$ 8,731
Lease Receivables
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for credit loss as of		259		233
Provisions		0		22
(Write-offs, net)		(4)		(4)
Foreign exchange and other		0		(3)
Allowance for credit loss as of		255		248
Total financing receivables before allowance for credit loss	[1]	3,360		3,509
Loan Receivables
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for credit loss as of		87		98
Provisions		4		(13)
Recoveries, net		0		1
Foreign exchange and other		(1)		(2)
Allowance for credit loss as of		90		84
Total financing receivables before allowance for credit loss	[1]	1,963		1,744
Financed Service Contracts and Other
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for credit loss as of		36		18
Provisions		0		19
Recoveries, net				0
(Write-offs, net)		(3)
Foreign exchange and other		0		(1)
Allowance for credit loss as of		33		36
Total financing receivables before allowance for credit loss	[1]	$ 3,598		$ 3,071

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