Note 9 - Earnings Per Common Share (Tables)
|3 Months Ended|
Mar. 31, 2019
|Schedule of Weighted Average Number of Shares [Table Text Block]||
Tabular disclosure of the weighted average number of shares used in calculating basic net earnings per share (or unit) and diluted earnings per share (or unit).
Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef