Note 4 - Net Income Per Share - Components of Common Shares Outstanding (Details) - shares |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Dec. 31, 2016 |
Dec. 31, 2015 |
Dec. 31, 2016 |
Dec. 31, 2015 |
|
| Weighted average common shares outstanding – basic (in shares) | 4,836,336 | 4,844,845 | 4,835,639 | 4,853,970 |
| Dilutive effect of stock options (in shares) | 3,441 | 2,125 | 2,176 | 3,133 |
| Shares used in computing net income per share – diluted (in shares) | 4,839,777 | 4,846,970 | 4,837,815 | 4,857,103 |