Note 2 - Investments and Fair Value Measurement (Details Textual) - USD ($) $ in Thousands |
3 Months Ended | 9 Months Ended | 12 Months Ended | ||
|---|---|---|---|---|---|
Sep. 30, 2022 |
Sep. 30, 2021 |
Sep. 30, 2022 |
Sep. 30, 2021 |
Dec. 31, 2021 |
|
| Other-than-temporary Impairment Loss, Debt Securities, Available-for-Sale | $ 0 | $ 0 | |||
| Debt Securities, Available-for-Sale, Realized Gain (Loss), Total | $ 0 | $ 0 | 0 | $ 0 | |
| Fair Value, Measurement with Unobservable Inputs Reconciliation, Liability, Transfers Into Level 3 | $ 0 | $ 0 | $ 0 | $ 0 | |