Valuation And Qualifying Accounts (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Jul. 28, 2012	Jul. 30, 2011	Jul. 31, 2010
Lease Receivables
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at beginning of fiscal year	$ 237	$ 207	$ 213
Provisions	22	31	25
Write-offs net of recoveries	(2)	(13)	(1)
Foreign exchange and other	(10)	12	(30)
Balance at end of fiscal year	247	237	207
Loan Receivables
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at beginning of fiscal year	103	73	88
Provisions	22	43	43
Write-offs net of recoveries		(18)	(69)
Foreign exchange and other	(3)	5	11
Balance at end of fiscal year	122	103	73
Accounts Receivable
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at beginning of fiscal year	204	235	216
Provisions	19	7	44
Write-offs net of recoveries	(16)	(38)	(25)
Balance at end of fiscal year	$ 207	$ 204	$ 235