Note 4 - Net (Loss) Income Per Common Share - Computation of Basic and Diluted Net Income Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Net (loss) income	$ (103,462)	$ 33,372	$ 50,867
Basic - weighted-average shares outstanding: (in shares)	27,409,838	27,617,627	26,737,425
Employee stock options and other (in shares)	0	35,472	158,932
Diluted - weighted-average shares outstanding: (in shares)	27,409,838	27,653,099	26,896,357
Basic (in dollars per share)	$ (3.77)	$ 1.21	$ 1.90
Diluted (in dollars per share)	$ (3.77)	$ 1.21	$ 1.89