Note 5 - Fair Value of Financial Instruments - Assets Measured on Recurring Basis (Details) - USD ($)
|
Sep. 30, 2020 |
Mar. 31, 2020 |
| Total |
$ 67,555,355
|
$ 70,594,742
|
| Money Market Funds [Member] |
|
|
| Total |
3,546,052
|
7,903,433
|
| Corporate Bond Securities [Member] |
|
|
| Total |
64,009,303
|
62,691,309
|
| Fair Value, Recurring [Member] |
|
|
| Total |
67,555,355
|
70,594,742
|
| Fair Value, Recurring [Member] | Money Market Funds [Member] |
|
|
| Total |
3,546,052
|
7,903,433
|
| Fair Value, Recurring [Member] | Corporate Bond Securities [Member] |
|
|
| Total |
64,009,303
|
62,691,309
|
| Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] |
|
|
| Total |
3,546,052
|
7,903,433
|
| Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Money Market Funds [Member] |
|
|
| Total |
3,546,052
|
7,903,433
|
| Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Corporate Bond Securities [Member] |
|
|
| Total |
|
|
| Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] |
|
|
| Total |
64,009,303
|
62,691,309
|
| Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Money Market Funds [Member] |
|
|
| Total |
|
|
| Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Corporate Bond Securities [Member] |
|
|
| Total |
$ 64,009,303
|
$ 62,691,309
|