Note 9 - Cash Dividends (Details Textual) - USD ($)	1 Months Ended	6 Months Ended
	Jan. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Payments of Dividends, Total		$ 2,600,000	$ 2,600,000
Dividends Accrued		$ 104,346	$ 52,383
Subsequent Event [Member]
Quarterly Indicated Per Share Dividend Rate (in dollars per share)	$ 0.05
Dividends Payable, Date to be Paid	Feb. 09, 2021
Dividends Payable, Date of Record	Feb. 01, 2021
Annual Indicated per Share Dividend Rate (in dollars per share)	$ 0.20