Consolidated Balance Sheets (Parenthetical) (USD $) In Millions, except Per Share data	Apr. 30, 2011	Jul. 31, 2010
Consolidated Balance Sheets
Accounts receivable, allowance for doubtful accounts	$ 200	$ 235
Preferred stock, no par value
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	5,501	5,655
Common stock, shares outstanding	5,501	5,655