Note 4 - Summary of Significant Accounting Policies - Weighted Average Number of Shares (Details) - shares |
3 Months Ended | |
|---|---|---|
Jun. 30, 2021 |
Jun. 30, 2020 |
|
| Weighted average common shares outstanding – basic (in shares) | 4,833,232 | 4,835,038 |
| Dilutive effect of stock options (in shares) | 3,589 | 119 |
| Shares used in computing net income per share – diluted (in shares) | 4,836,821 | 4,835,157 |