Consolidated Balance Sheets [Parenthetical] (USD $)	Jul. 31, 2011	Apr. 30, 2011
Common stock, par value (in dollars per share)	$ 0.10	$ 0.10
Common stock, shares authorized	20,000,000	20,000,000
Common stock, shares issued	7,420,704	7,420,704
Treasury Stock, shares	1,424,492	1,424,492