| Schedule of Weighted Average Number of Shares [Table Text Block] |
| | | | | | | | | | | | | Weighted average common shares outstanding – basic | | | 4,841,010 | | | | 4,835,564 | | | Dilutive effect of stock options | | | 4,622 | | | | 2,255 | | Shares used in computing net income per share – diluted | | | 4,845,632 | | | | 4,837,819 | | | | | Six Months Ended Sept. 30 | | | | | | | | | | Weighted average common shares outstanding – basic | | | 4,841,010 | | | | 4,835,289 | | | Dilutive effect of stock options | | | 4,897 | | | | 2,004 | | Shares used in computing net income per share – diluted | | | 4,845,907 | | | | 4,837,293 | | |