Note 1 - Summary of Significant Accounting Policies - Summary of Deferred Compensation Plan (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Deferred compensation plan assets	$ 78,381	$ 63,022
Deferred compensation plan liabilities	81,287	64,981
Other Long-term Assets [Member]
Deferred compensation plan assets	78,381	63,022
Accrued Compensation and Related Benefits [Member]
Deferred compensation plan liabilities	384	118
Other Long-term Liabilities [Member]
Deferred compensation plan liabilities	80,903	64,863
Cash Surrender Value [Member]
Deferred compensation plan assets	23,545	19,089
Mutual Funds and Money Market Funds, Fair Value [Member]
Deferred compensation plan assets	$ 54,836	$ 43,933