Note 3 - Income Taxes (Details Textual) |
3 Months Ended | 6 Months Ended | 12 Months Ended | |||
---|---|---|---|---|---|---|
Dec. 31, 2018 |
Dec. 31, 2017 |
Dec. 31, 2018 |
Dec. 31, 2017 |
Jun. 30, 2019 |
Jun. 30, 2018 |
|
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent | 28.00% | |||||
Effective Income Tax Rate Reconciliation, Percent, Total | 25.10% | 16.00% | 25.00% | 23.50% | ||
Scenario, Forecast [Member] | ||||||
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent | 21.00% | |||||
Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member] | ||||||
Income Tax Examination, Year under Examination | 2015 2016 |