Consolidated Balance Sheets (Parenthetical) (USD $) In Millions, except Per Share data, unless otherwise specified	Jan. 26, 2013	Jul. 28, 2012
Statement of Financial Position [Abstract]
Accounts receivable, allowance for doubtful accounts of $218 at January 26, 2013 and $207 at July 28, 2012	$ 218	$ 207
Preferred Stock, No Par Value	$ 0	$ 0
Preferred stock, shares authorized	5	5
Preferred stock, issued	0	0
Preferred stock, outstanding	0	0
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	20,000	20,000
Common stock, shares issued	5,323	5,298
Common stock, shares outstanding	5,323	5,298