Note 2 - Investments and Fair Value Measurement (Details Textual) - USD ($) $ in Thousands |
12 Months Ended | |
|---|---|---|
Dec. 31, 2022 |
Dec. 31, 2021 |
|
| Debt Securities, Available-for-sale, Realized Gain (Loss), Total | $ 0 | $ 0 |
| Other-than-temporary Impairment Loss, Debt Securities, Available-for-Sale | 0 | 0 |
| OCI, Debt Securities, Available-for-Sale, Transfer from Held-to-Maturity, Gain (Loss), before Adjustment, after Tax | $ 0 | $ 0 |