Note 5 - Fair Value Measurements - Fair Value Measurements (Details) - USD ($) $ in Thousands |
Mar. 31, 2023 |
Jun. 30, 2022 |
|---|---|---|
| Investments (2) | $ 95,171 | $ 11,199 |
| Total | 115,784 | 62,234 |
| Money Market Funds [Member] | ||
| Corporate money market funds (1) | 20,613 | 51,035 |
| Fair Value, Inputs, Level 1 [Member] | ||
| Investments (2) | 0 | 0 |
| Total | 20,613 | 51,035 |
| Fair Value, Inputs, Level 1 [Member] | Money Market Funds [Member] | ||
| Corporate money market funds (1) | 20,613 | 51,035 |
| Fair Value, Inputs, Level 2 [Member] | ||
| Investments (2) | 95,171 | 11,199 |
| Total | 95,171 | 11,199 |
| Fair Value, Inputs, Level 2 [Member] | Money Market Funds [Member] | ||
| Corporate money market funds (1) | 0 | 0 |
| Fair Value, Inputs, Level 3 [Member] | ||
| Investments (2) | 0 | 0 |
| Total | 0 | 0 |
| Fair Value, Inputs, Level 3 [Member] | Money Market Funds [Member] | ||
| Corporate money market funds (1) | $ 0 | $ 0 |