Note 1 - Summary of Significant Accounting Policies - Summary of Deferred Compensation Plan (Details) - USD ($) $ in Thousands |
Dec. 31, 2022 |
Dec. 31, 2021 |
|---|---|---|
| Deferred compensation plan assets | $ 63,022 | $ 53,172 |
| Deferred compensation plan liabilities | 64,981 | 55,771 |
| Other Long-term Assets [Member] | ||
| Deferred compensation plan assets | 63,022 | 53,172 |
| Accrued Compensation and Related Benefits [Member] | ||
| Deferred compensation plan liabilities | 118 | 282 |
| Other Long-term Liabilities [Member] | ||
| Deferred compensation plan liabilities | 64,863 | 55,489 |
| Cash Surrender Value [Member] | ||
| Deferred compensation plan assets | 19,089 | 21,386 |
| Mutual Funds and Money Market Funds, Fair Value [Member] | ||
| Deferred compensation plan assets | $ 43,933 | $ 31,786 |