Financing Receivables and Guarantees (Summary Of Allowances For Credit Loss And Related Financing Receivables) (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Jul. 27, 2013	Jul. 28, 2012	Jul. 30, 2011
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	$ 380	$ 367	$ 301
Provisions	11	31	82
Write-offs, net of recoveries	(46)	(3)	(33)
Foreign exchange and other	(1)	(15)	17
Ending balance	344	380	367
Financing Receivable, Gross	8,292	7,626	6,966
Lease Receivables
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	247	237	207
Provisions	21	22	31
Write-offs, net of recoveries	(30)	(2)	(13)
Foreign exchange and other	0	(10)	12
Ending balance	238	247	237
Financing Receivable, Gross	3,507	3,179	2,861
Loan Receivables
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	122	103	73
Provisions	(20)	22	43
Write-offs, net of recoveries	(15)	0	(18)
Foreign exchange and other	(1)	(3)	5
Ending balance	86	122	103
Financing Receivable, Gross	1,649	1,796	1,468
Financed Service Contracts & Other
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	11	27	21
Provisions	10	(13)	8
Write-offs, net of recoveries	(1)	(1)	(2)
Foreign exchange and other	0	(2)	0
Ending balance	20	11	27
Financing Receivable, Gross	$ 3,136	$ 2,651	$ 2,637