Note 9 - Fair Value Measurements (Details Textual) - USD ($) |
Dec. 31, 2016 |
Mar. 31, 2016 |
|---|---|---|
| Fair Value, Inputs, Level 1 [Member] | ||
| Available-for-sale Securities | $ 83,010,489 | $ 84,045,869 |
| Fair Value, Inputs, Level 2 [Member] | ||
| Available-for-sale Securities | 1,313,452 | 1,346,850 |
| Fair Value, Inputs, Level 3 [Member] | ||
| Assets, Fair Value Disclosure | 0 | 0 |
| Financial and Nonfinancial Liabilities, Fair Value Disclosure | $ 0 | $ 0 |