Note 5 - Fair Value of Financial Instruments - Assets Measured on Recurring Basis (Details) - USD ($)
|
Jun. 30, 2020 |
Mar. 31, 2020 |
| Total |
$ 70,315,124
|
$ 70,594,742
|
| Money Market Funds [Member] |
|
|
| Total |
6,086,051
|
7,903,433
|
| Corporate Bond Securities [Member] |
|
|
| Total |
64,229,073
|
62,691,309
|
| Fair Value, Recurring [Member] |
|
|
| Total |
70,315,124
|
70,594,742
|
| Fair Value, Recurring [Member] | Money Market Funds [Member] |
|
|
| Total |
6,086,051
|
7,903,433
|
| Fair Value, Recurring [Member] | Corporate Bond Securities [Member] |
|
|
| Total |
64,229,073
|
62,691,309
|
| Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] |
|
|
| Total |
6,086,051
|
7,903,433
|
| Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Money Market Funds [Member] |
|
|
| Total |
6,086,051
|
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 |
64,229,073
|
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 |
$ 64,229,073
|
$ 62,691,309
|