Note 3 - Share-based Compensation - Components of Share-based Compensation (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Restricted Stock Units (RSUs) [Member]
Pretax compensation expense	$ 13,409	$ 14,731	$ 25,817	$ 27,454
Tax benefit	3,540	3,799	6,816	7,080
Restricted share unit expense, net of tax	9,869	10,932	19,001	20,374
Performance Shares [Member]
Pretax compensation expense	5,746	5,866	11,747	12,391
Tax benefit	1,517	1,513	3,101	3,196
Restricted share unit expense, net of tax	$ 4,229	$ 4,353	$ 8,646	$ 9,195