Note 9 - Retirement Savings Plans (Details Textual) - USD ($) |
12 Months Ended | |
---|---|---|
Dec. 31, 2017 |
Dec. 31, 2016 |
|
Defined Contribution Plan, Employer Matching Contribution, Percent of Match | 100.00% | 100.00% |
Defined Contribution Plan, Maximum Annual Contributions Per Employee, Percent | 4.00% | 4.00% |
Defined Contribution Plan, Employer Contribution Amount | $ 29,952 | $ 33,143 |
Defined Contribution Plan, Employer Discretionary Contribution Amount | $ 0 | $ 0 |