Note 2 - Earnings Per Common Share - Computation of Earnings Per Common Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Net income available to common stockholders	$ 15,696	$ 23,420
Earnings allocated to participating securities	(42)	(44)
Income attributable to common stock	$ 15,654	$ 23,376
Weighted average common shares outstanding, including participating securities (in shares)	38,423	39,178
Weighted average participating securities (in shares)	(104)	(74)
Weighted average common shares outstanding (in shares)	38,319	39,104
Incremental shares from assumed conversions of options, performance units and restricted shares (in shares)	193	197
Weighted average common and equivalent shares outstanding (in shares)	38,512	39,301
Earnings per common share:
Basic (in dollars per share)	$ 0.41	$ 0.6
Diluted (in dollars per share)	$ 0.41	$ 0.59