Note 12 - Pension and Other Postretirement Benefit Plans - Assumptions Used to Develop Periodic Pension Benefit for the Retirement Plan (Details) |
12 Months Ended | ||
---|---|---|---|
Dec. 31, 2017 |
Dec. 31, 2016 |
Dec. 31, 2015 |
|
Weighted average discount rate | 3.88% | 4.06% | 3.76% |
Rate of increase in future compensation levels | 0.00% | 0.00% | 0.00% |
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Rate of Return on Plan Assets | 0.00% | 0.00% | 0.00% |
Retirement Plan [Member] | |||
Weighted average discount rate | 3.88% | 4.06% | 3.76% |
Rate of increase in future compensation levels | 0.00% | 0.00% | 0.00% |
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Rate of Return on Plan Assets | 7.00% | 7.25% | 7.50% |