Note 11 - Related Party Transactions (Details Textual)
12 Months Ended
Dec. 01, 2016
USD ($)
Mar. 01, 2016
USD ($)
Jun. 30, 2015
USD ($)
Dec. 31, 2016
USD ($)
Dec. 31, 2015
USD ($)
Dec. 31, 2014
USD ($)
Jun. 30, 2016
Jul. 01, 2015
Loans and Leases Receivable, Net Amount       $ 725,860,000 $ 724,926,000      
Subordinated Debt     $ 14,000,000 10,000,000 $ 14,000,000 $ 25,000,000    
Number of Noteholders Electing to Sell Subordinated Notes         7      
Subordinated Notes of Nonrelated Parties Purchased by Group         $ 10,000,000      
Repayments of Subordinated Debt     $ 11,000,000          
Subordinated Liabilities, Extinguished       4,000,000 11,000,000      
Related Party Transaction, Interest Paid $ 4,000,000              
Related Party Transaction, Payments of Previously Deferred and Accrued Interest   $ 10,800,000            
Subordinated Debt [Member]                
Debt Instrument, Interest Rate, Stated Percentage     9.00%       9.00% 4.50%
Percent of Principal Amount Outstanding, Prepayment     44.00%          
Repayments of Subordinated Debt 4,000,000              
Director [Member]                
Loans and Leases Receivable, Net Amount       381        
Related Party Transaction, Amount of Participation Interest         5,200,000      
Related Party Transaction, Amount of Participation Interest Outstanding         $ 4,400,000      
Director [Member] | Annual Servicing Fee on Participation Balance [Member]                
Related Party Transaction, Rate         0.25%      
Director [Member] | Line of Credit [Member] | Commercial Loan [Member]                
Loans and Leases Receivable, Net Amount         $ 11,000,000      
Directors, Executive Officers and Their Related Parties [Member]                
Related Party Deposit Liabilities       119,300,000 106,100,000      
Related Party Transactions, Interest Paid on Deposits       196,000 276,000 97,000    
Related Party Transaction, Expenses from Transactions with Related Party       2,600,000 2,100,000 $ 2,700,000    
Related Party Transactions, Subordinated Debt       6,200,000 8,600,000      
Subordinated Liabilities, Extinguished     $ 6,800,000          
Related Party Transaction, Interest Paid $ 2,500,000     395,000 233,000      
Related Party Transaction, Payments of Previously Deferred and Accrued Interest   $ 3,900,000            
Interest Expense, Related Party       386,000 606,000      
Related Party Transactions Interest Accrued and Unpaid       $ 24,000 $ 3,900,000      
Related Party Noteholders [Member]                
Debt Instrument, Face Amount     6,400,000          
Repayments of Subordinated Debt     11,000,000          
Subordinated Liabilities, Additions     $ 6,400,000