Note 13 - Earnings Per Common Share - Summary of Earnings Per Share Calculation (Details) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018
Income available to common stockholders									$ 6,979,863	$ 3,613,710
Weighted Average Shares of Common Stock Outstanding (in shares)									2,849,239	2,799,706
Net Income Per Common Share - Basic (in dollars per share)	$ 0.58	$ 0.59	$ 0.66	$ 0.63	$ 0.50	$ 0.55	$ 0.14	$ 0.13	$ 2.45	$ 1.29
Options and warrants under convertible note (in shares)									428,618	381,866
Weighted Average Shares of Common Stock Outstanding - Diluted (in shares)									3,277,857	3,181,572
Income available to common stockholders									$ 6,979,863	$ 3,613,710
Net Income Per Common Share - Diluted (in dollars per share)	$ 0.51	$ 0.52	$ 0.57	$ 0.55	$ 0.43	$ 0.48	$ 0.13	$ 0.11	$ 2.13	$ 1.14