Financing Receivables And Guarantees (Allowance For Credit Loss And Related Financing Receivables) (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Oct. 26, 2013	Oct. 27, 2012	Jul. 27, 2013
Financing Receivable, Allowance for Credit losses [Line Items]
Financing Receivable, Allowance for Credit Losses	$ 344	$ 380
Provisions	3	(11)
Foreign exchange and other	3	5
Financing Receivable, Allowance for Credit Losses	350	374
Gross Financing Receivable, Net of Unearned	8,375	7,795	8,292
Lease Receivables
Financing Receivable, Allowance for Credit losses [Line Items]
Financing Receivable, Allowance for Credit Losses	238	247
Provisions	(3)	(2)
Foreign exchange and other	2	3
Financing Receivable, Allowance for Credit Losses	237	248
Gross Financing Receivable, Net of Unearned	3,549	3,340	3,507
Loan Receivables
Financing Receivable, Allowance for Credit losses [Line Items]
Financing Receivable, Allowance for Credit Losses	86	122
Provisions	6	(10)
Foreign exchange and other	1	2
Financing Receivable, Allowance for Credit Losses	93	114
Gross Financing Receivable, Net of Unearned	1,808	1,816	1,649
Financed Service Contracts And Other
Financing Receivable, Allowance for Credit losses [Line Items]
Financing Receivable, Allowance for Credit Losses	20	11
Provisions	0	1
Foreign exchange and other	0	0
Financing Receivable, Allowance for Credit Losses	20	12
Gross Financing Receivable, Net of Unearned	$ 3,018	$ 2,639	$ 3,136