Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Jul. 31, 2012	Jul. 31, 2011
Allowance for doubtful accounts	$ 527	$ 549
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	61,777,849	61,697,349
Treasury, shares	8,857,339	5,857,339