Annual report pursuant to Section 13 and 15(d)

Stock Options - Stock options activity table - Key Employees (Details)

v3.2.0.727
Stock Options - Stock options activity table - Key Employees (Details) - $ / shares
3 Months Ended 12 Months Ended
Jul. 31, 2009
Apr. 30, 2015
Apr. 30, 2014
Shares      
Beginning Balance (in shares)   264,244  
Granted (in shares) 8,333    
Exercised (in shares)      
Expired (in shares)   (138,498)  
Ending balance (in shares)   125,746 264,244
Weighted average exercise price per share      
Beginning balance (in dollars per share)   $ 12.42  
Granted (in dollars per share)      
Exercised (in dollars per share)      
Ending balance (in dollars per share)   $ 8.48 $ 12.42
Stock Options | Key Employees      
Shares      
Beginning Balance (in shares)   245,577 280,242
Granted (in shares)      
Exercised (in shares)      
Expired (in shares)   (119,831) (34,665)
Ending balance (in shares)   125,746 245,577
Exercise price per share      
Beginning balance (in dollars per share) lower range   $ 2.44 $ 2.44
Beginning balance (in dollars per share) upper range   $ 19.20 $ 24.54
Granted (in dollars per share) lower range      
Granted (in dollars per share) upper range      
Exercised (in dollars per share) lower range      
Exercised (in dollars per share) upper range      
Expired (in dollars per share) lower range   $ 6.72 $ 6.72
Expired (in dollars per share) upper range   19.20 24.54
Ending balance (in dollars per share) lower range   2.44 2.44
Ending balance (in dollars per share) upper range   15.42 19.20
Weighted average exercise price per share      
Beginning balance (in dollars per share)   $ 12.27 $ 12.04
Granted (in dollars per share)      
Exercised (in dollars per share)      
Expired (in dollars per share)   $ 16.24 $ 10.41
Ending balance (in dollars per share)   $ 8.48 $ 12.27