Note 6 - Dividends (Details Textual) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Common Stock, Dividends, Per Share, Declared	$ 0.06	$ 0.06
Payments of Ordinary Dividends, Common Stock	$ 4,874	$ 4,975
Paid Quarterly [Member]
Common Stock, Dividends, Per Share, Declared	$ 0.06	$ 0.06
Payments of Ordinary Dividends, Common Stock	$ 4,900	$ 5,000