Annual report pursuant to Section 13 and 15(d)

Note 5 - Employee Benefit Plans (Details Textual)

v3.8.0.1
Note 5 - Employee Benefit Plans (Details Textual) - USD ($)
 12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Defined Contribution Plan, Employer Discretionary Contribution Amount   $ 100,000 $ 100,000 $ 100,000
Other Comprehensive (Income) Loss, Defined Benefit Plan, Reclassification Adjustment from AOCI, after Tax   100,000 100,000 100,000
Other Comprehensive (Income) Loss, Defined Benefit Plan, Reclassification Adjustment from AOCI, Tax   100,000 100,000 100,000
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Reclassification Adjustment from AOCI, after Tax   $ 70,000 $ 91,000 $ 96,000
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Rate of Return on Plan Assets   7.00% 7.00% 7.00%
Defined Benefit Plan Benefit Payment Term   10 years    
Inflation Rate [Member]        
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Rate of Return on Plan Assets   2.50%    
Minimum [Member]        
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Rate of Return on Plan Assets   2.50%    
Minimum [Member] | Fixed Income Securities [Member]        
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage   30.00%    
Minimum [Member] | Equity Securities [Member]        
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage   20.00%    
Maximum [Member]        
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Rate of Return on Plan Assets   8.50%    
Maximum [Member] | Fixed Income Securities [Member]        
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage   80.00%    
Maximum [Member] | Equity Securities [Member]        
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage   60.00%    
Scenario, Forecast [Member]        
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, after Tax $ 100,000      
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Reclassification Adjustment from AOCI, after Tax $ 0