Note 3 - Earnings Per Share - Earnings Per Share Calculation (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Numerator for basic and diluted earnings per share – Net income available to common shareholders	$ 72,438	$ 78,661	$ 132,760	$ 150,269
Denominator for basic earnings per share – weighted average shares outstanding (in shares)	78,300	78,270	78,991	78,706
Effect of dilutive securities– Employee and director stock options and restricted share awards (in shares)	2,187	2,508	2,454	2,761
Denominator for diluted earnings per share – adjusted weighted average shares outstanding and assumed conversions (in shares)	80,487	80,778	81,445	81,467
Basic earnings per common share (in dollars per share)	$ 0.93	$ 1.01	$ 1.68	$ 1.91
Diluted earnings per common share and common share equivalents (in dollars per share)	$ 0.9	$ 0.97	$ 1.63	$ 1.84