Note 6 - Net Income Per Share - Net Income Per Share Basic and Diluted (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Net income	$ 133,791	$ 92,541
Basic (in shares)	47,851	48,635
Effect of dilutive securities (in shares)	155	293
Diluted (in shares)	48,006	48,928
Basic (in dollars per share)	$ 2.8	$ 1.9
Diluted (in dollars per share)	$ 2.79	$ 1.89