Note 12 - Other Income (Expense), Net - Interest and Other Income Components (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Interest income	$ 6,071	$ 3,584	$ 16,844	$ 10,378
Amortization of discount (premium) on available-for-sale securities	1,647	(1,102)	1,591	(3,682)
Gain (loss) on deferred compensation plan investments	(1,611)	(1,330)	3,411	(8,607)
Charitable contributions	(3,850)	(1,700)	(9,650)	(4,700)
Gain on sales of equity investments	0	0	1,424	(0)
Other	32	553	509	891
Total	$ 2,289	$ 5	$ 14,129	$ (5,720)