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. 28, 2012	Jul. 30, 2011
Lease Receivables
Summary Of Allowances For Credit Loss And The Related Financing Receivables [Line Items]
Beginning balance allowance for credit loss	$ 237	$ 207
Provisions	22	31
Write-offs net of recoveries	(2)	(13)
Foreign exchange and other	(10)	12
Ending balance allowance for credit loss	247	237
Gross receivables net of unearned income	3,179	2,861
Loan Receivables
Summary Of Allowances For Credit Loss And The Related Financing Receivables [Line Items]
Beginning balance allowance for credit loss	103	73
Provisions	22	43
Write-offs net of recoveries		(18)
Foreign exchange and other	(3)	5
Ending balance allowance for credit loss	122	103
Gross receivables net of unearned income	1,796	1,468
Financed Service Contracts & Other
Summary Of Allowances For Credit Loss And The Related Financing Receivables [Line Items]
Beginning balance allowance for credit loss	27	21
Provisions	(13)	8
Write-offs net of recoveries	(1)	(2)
Foreign exchange and other	(2)
Ending balance allowance for credit loss	11	27
Gross receivables net of unearned income	2,651	2,637
Total Allowance
Summary Of Allowances For Credit Loss And The Related Financing Receivables [Line Items]
Beginning balance allowance for credit loss	367	301
Provisions	31	82
Write-offs net of recoveries	(3)	(33)
Foreign exchange and other	(15)	17
Ending balance allowance for credit loss	380	367
Gross receivables net of unearned income	$ 7,626	$ 6,966