Note 13 - Subsequent Event (Details Textual) - $ / shares		3 Months Ended				12 Months Ended
	Feb. 08, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019
Common Stock, Dividends, Per Share, Declared (in dollars per share)		$ 0.20	$ 0.20	$ 0.20	$ 0.20	$ 0.80	$ 0.64
Subsequent Event [Member]
Common Stock, Dividends, Per Share, Declared (in dollars per share)	$ 0.20