Note 7 - 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, 2024	Mar. 31, 2023
Net income	$ 92,541	$ 109,802
Weighted-average outstanding shares — basic (in shares)	48,635	47,234
Effect of dilutive securities (in shares)	293	1,421
Weighted-average outstanding shares — diluted (in shares)	48,928	48,655
Earnings per share, basic (in dollars per share)	$ 1.9	$ 2.32
Earnings per share, diluted (in dollars per share)	$ 1.89	$ 2.26