Note 10 - Income Per Common Share - Income Per Share (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Basic Income Per Common Share	$ 2,428,499	$ (342,984)	$ 4,548,863	$ 1,012,761
Weighted average common shares outstanding, basic (in shares)	4,452,798	4,404,029	4,445,750	4,397,907
Basic Income Per Common Share (in dollars per share)	$ 0.55	$ (0.08)	$ 1.02	$ 0.23
Effect of Dilutive Securities, Average Common Shares Outstanding (in shares)	51,166		55,631	71,513
Diluted Income Per Common Share	$ 2,428,499	$ (342,984)	$ 4,548,863	$ 1,012,761
Weighted average common shares outstanding, diluted (in shares)	4,503,964	4,404,029	4,501,381	4,469,420
Diluted Income Per Common Share (in dollars per share)	$ 0.54	$ (0.08)	$ 1.01	$ 0.23