Note 10 - Income Taxes (Details Textual) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent 34.00% 34.00% 34.00%
Operating Loss Carryforwards $ 50,400 $ 55,600  
Deferred Tax Assets, Operating Loss Carryforwards 17,123 18,910  
Charitable Contribution Carryovers 690 1,000  
Deferred Tax Assets, Charitable Contribution Carryforwards 235 355  
Deferred Tax Assets, Tax Credit Carryforwards, Alternative Minimum Tax 2,600 2,466  
Deferred Tax Assets, Valuation Allowance 355  
Deferred Tax Assets, Charitable Contribution Utilized $ 353    
Charitable Contribution [Member]      
Deferred Tax Assets, Valuation Allowance   355  
AMT Credit [Member]      
Tax Credit Carryforward, Amount   $ 2,500