Condensed Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data	Apr. 30, 2011	Jul. 31, 2010
Accounts receivable:
Allowance for doubtful accounts	$ 524	$ 422
Stockholders' equity:
Preferred stock, shares authorized	1,000,000	1,000,000
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.10	$ 0.10
Common stock, shares authorized	250,000,000	250,000,000
Common stock, shares issued	61,697,349	57,318,849
Treasury, shares	5,857,339	5,857,339