Stock Award Plan (Details) (USD $)
In Millions, except Share data, unless otherwise specified
0 Months Ended 9 Months Ended 12 Months Ended
Oct. 31, 2011
Apr. 30, 2013
Jul. 31, 2012
Stock Award Plan [Abstract]      
Shares awarded (in shares) 62,099    
Shares awarded, value $ 0.9    
Share-based award, vesting period   3 years  
Excess tax benefits accumulated in Capital in Excess of Par Value   0.3 0.3
Unrecognized compensation expense   $ 0.4 $ 0.8