Note 5 - 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, 2026	Mar. 31, 2025
Net income	$ 193,226	$ 135,052
Basic (in shares)	49,097	47,851
Effect of dilutive securities (in shares)	145	155
Diluted (in shares)	49,242	48,006
Basic (in dollars per share)	$ 3.94	$ 2.82
Diluted (in dollars per share)	$ 3.92	$ 2.81