Note 9 - Fair Value Measurements (Details Textual) - USD ($) |
Jun. 30, 2015 |
Mar. 31, 2015 |
|---|---|---|
| Fair Value, Inputs, Level 1 [Member] | ||
| Available-for-sale Securities | $ 86,617,442 | $ 89,625,984 |
| Fair Value, Inputs, Level 2 [Member] | ||
| Available-for-sale Securities | 1,374,147 | 1,387,111 |
| Available-for-sale Securities | $ 87,991,589 | $ 91,013,095 |