Financing Receivables and Operating Leases (Summary Of Allowances For Credit Loss And Related Financing Receivables) (Details) - USD ($) $ in Millions		12 Months Ended
		Jul. 25, 2015	Jul. 26, 2014	Jul. 27, 2013
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for credit loss as of		$ 349	$ 344	$ 380
Provisions		57	14	11
Recoveries (write-offs), net		(7)	(9)	(46)
Foreign exchange and other		(17)	0	(1)
Allowance for credit loss as of		382	349	344
Total financing receivables before allowance for credit loss	[1]	8,731	8,420	8,292
Lease Receivables
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for credit loss as of		233	238	247
Provisions		45	4	21
Recoveries (write-offs), net		(7)	(11)	(30)
Foreign exchange and other		(12)	2	0
Allowance for credit loss as of		259	233	238
Total financing receivables before allowance for credit loss	[1]	3,395	3,527	3,507
Loan Receivables
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for credit loss as of		98	86	122
Provisions		(8)	9	(20)
Recoveries (write-offs), net				(15)
Financing Receivable, Allowance for Credit Losses, Recovery		1	5
Foreign exchange and other		(4)	(2)	(1)
Allowance for credit loss as of		87	98	86
Total financing receivables before allowance for credit loss	[1]	1,763	1,683	1,649
Financed Service Contracts and Other
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for credit loss as of		18	20	11
Provisions		20	1	10
Recoveries (write-offs), net		(1)	(3)	(1)
Foreign exchange and other		(1)	0	0
Allowance for credit loss as of		36	18	20
Total financing receivables before allowance for credit loss	[1]	$ 3,573	$ 3,210	$ 3,136

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