Schedule II - Valuation and Qualifying Accounts (Details) - USD ($) $ in Millions	12 Months Ended
	Jul. 25, 2015	Jul. 26, 2014	Jul. 27, 2013
Financing Receivables
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at beginning of fiscal year	$ 349	$ 344	$ 380
Provisions	57	14	11
(Write-offs) recoveries, net	(7)	(9)	(46)
Foreign exchange and other	(17)		(1)
Balance at end of fiscal year	382	349	344
Accounts Receivable
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at beginning of fiscal year	265	228	207
Provisions	77	65	33
(Write-offs) recoveries, net	(40)	(28)	(12)
Foreign exchange and other	0		0
Balance at end of fiscal year	$ 302	$ 265	$ 228