Note 7 - Pledged Assets, Notes Payable and Long-Term Debt (Details) - Long-Term Debt (Parentheticals) (USD $)
9 Months Ended 12 Months Ended
Jan. 31, 2014
Apr. 30, 2013
Debt Instrument [Line Items]    
Basis Spread on Variable Rate 0.50%  
Operating Line of Credit, Limit on Borrowing Capacity (in Dollars) $ 6,000,000  
Pre-reset Interest Rate [Member] | Secured Debt [Member]
   
Debt Instrument [Line Items]    
Basis Spread on Variable Rate 0.45% 0.45%
Secured Debt [Member]
   
Debt Instrument [Line Items]    
Maturity Date Sep. 01, 2026 Sep. 01, 2026
Interest Rate 1.89% 1.89%
Line of Credit [Member]
   
Debt Instrument [Line Items]    
Basis Spread on Variable Rate 0.50% 0.50%
Maturity Date Oct. 30, 2015 Oct. 30, 2015
Interest Rate 2.75% 2.75%
Operating Line of Credit, Limit on Borrowing Capacity (in Dollars) $ 6,000,000 $ 6,000,000
Operating Line of Credit, Prime Rate 3.25% 3.25%