Financing Receivables And Guarantees (Allowance For Credit Loss And Related Financing Receivables) (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jan. 25, 2014	Jan. 26, 2013	Jan. 25, 2014	Jan. 26, 2013	Jul. 27, 2013
Financing Receivable, Allowance for Credit losses [Line Items]
Financing Receivable, Allowance for Credit Losses	$ 350	$ 374	$ 344	$ 380
Provisions	29	(13)	32	(24)
Recoveries (write-offs), net	1		1
Foreign exchange and other	(6)	0	(3)	5
Financing Receivable, Allowance for Credit Losses	374	361	374	361
Gross Financing Receivable, Net of Unearned	8,018	8,092	8,018	8,092	8,292
Lease Receivables
Financing Receivable, Allowance for Credit losses [Line Items]
Financing Receivable, Allowance for Credit Losses	237	248	238	247
Provisions	18	(1)	15	(3)
Recoveries (write-offs), net	1		1
Foreign exchange and other	(2)	0	0	3
Financing Receivable, Allowance for Credit Losses	254	247	254	247
Gross Financing Receivable, Net of Unearned	3,551	3,444	3,551	3,444	3,507
Loan Receivables
Financing Receivable, Allowance for Credit losses [Line Items]
Financing Receivable, Allowance for Credit Losses	93	114	86	122
Provisions	9	(14)	15	(24)
Recoveries (write-offs), net	0		0
Foreign exchange and other	(4)	1	(3)	3
Financing Receivable, Allowance for Credit Losses	98	101	98	101
Gross Financing Receivable, Net of Unearned	1,660	1,785	1,660	1,785	1,649
Financed Service Contracts And Other
Financing Receivable, Allowance for Credit losses [Line Items]
Financing Receivable, Allowance for Credit Losses	20	12	20	11
Provisions	2	2	2	3
Recoveries (write-offs), net	0		0
Foreign exchange and other	0	(1)	0	(1)
Financing Receivable, Allowance for Credit Losses	22	13	22	13
Gross Financing Receivable, Net of Unearned	$ 2,807	$ 2,863	$ 2,807	$ 2,863	$ 3,136