Note 5 - Income Taxes (Tables)
|6 Months Ended|
Jun. 30, 2018
|Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]||
Tabular disclosure of the reconciliation using percentage or dollar amounts of the reported amount of income tax expense attributable to continuing operations for the year to the amount of income tax expense that would result from applying domestic federal statutory tax rates to pretax income from continuing operations.
Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef