Financing Receivables and Operating Leases (Summary Of Allowances For Credit Loss And Related Financing Receivables) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Apr. 30, 2016	Apr. 25, 2015	Apr. 30, 2016	Apr. 25, 2015
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for credit loss as of	$ 365	$ 375	$ 382	$ 349
Provisions	17	(11)	12	31
(Write-offs, net)	(6)	(1)	(14)	(5)
Foreign exchange and other	7	(4)	3	(16)
Allowance for credit loss as of	383	359	383	359
Lease Receivables
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for credit loss as of	248	250	259	233
Provisions	7	(4)	3	25
(Write-offs, net)	(6)	(1)	(10)	(6)
Foreign exchange and other	1	(3)	(2)	(10)
Allowance for credit loss as of	250	242	250	242
Loan Receivables
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for credit loss as of	80	85	87	98
Provisions	8	(5)	2	(15)
Recoveries, net	0	0	0	1
Foreign exchange and other	5	0	4	(4)
Allowance for credit loss as of	93	80	93	80
Financed Service Contracts and Other
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for credit loss as of	37	40	36	18
Provisions	2	(2)	7	21
(Write-offs, net)	0	0	(4)	0
Foreign exchange and other	1	(1)	1	(2)
Allowance for credit loss as of	$ 40	$ 37	$ 40	$ 37