Note 3 - Share-based Compensation - Components of Share-based Compensation (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Restricted Stock Units (RSUs) [Member]
Pretax compensation expense	$ 12,722	$ 12,975
Tax benefit	3,252	3,250
Restricted share unit expense, net of tax	9,470	9,725
Performance Shares [Member]
Pretax compensation expense	6,526	6,166
Tax benefit	1,668	1,545
Restricted share unit expense, net of tax	$ 4,858	$ 4,621