Note 12 - Income Per Common Share - Income Per Share (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Basic Income Per Common Share	$ 1,897,776	$ 2,550,542	$ 5,886,004	$ 7,099,405
Basic Income Per Common Share (in shares)	4,337,615	4,396,241	4,328,145	4,429,066
Basic Income Per Common Share (in dollars per share)	$ 0.44	$ 0.58	$ 1.36	$ 1.60
Effect of Dilutive Securities, Average Common Shares Outstanding (in shares)	8,662	58,091	18,638	56,532
Diluted Income Per Common Share	$ 1,897,776	$ 2,550,542	$ 5,886,004	$ 7,099,405
Diluted Income Per Common Share (in shares)	4,346,277	4,454,332	4,346,783	4,485,598
Diluted Income Per Common Share (in dollars per share)	$ 0.44	$ 0.57	$ 1.35	$ 1.58