Note 6 - Shareholder's Equity - Declared Dividends (Details) - USD ($)	3 Months Ended
	Mar. 31, 2022	May 03, 2021
Per Share Dividend (in dollars per share)		$ 0.30
Dividend Declared May 4, 2020 [Member]
Per Share Dividend (in dollars per share)	$ 0.30
Total Amount	$ 6,081
Record Date	May 21, 2021
Dividend Declared July 20, 2020 [Member]
Per Share Dividend (in dollars per share)	$ 0.30
Total Amount	$ 6,102
Record Date	Aug. 13, 2021
Dividend Declared October 26, 2020 [Member]
Per Share Dividend (in dollars per share)	$ 0.30
Total Amount	$ 6,283
Record Date	Nov. 19, 2021
Dividend Declared January 19, 2021 [Member]
Per Share Dividend (in dollars per share)	$ 0.30
Total Amount	$ 6,294
Record Date	Feb. 18, 2022