Note 18 - Quarterly Data (Unaudited) - Summary of Quarterly Data (Unaudited) (Details) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2021	Dec. 31, 2020
Sales	$ 27,320,481	$ 26,397,857	$ 26,449,885	$ 23,994,004	$ 19,933,941	$ 21,277,797	$ 18,576,588	$ 25,281,574	$ 104,162,227	$ 85,069,900
Gross Profit	4,371,546	5,397,709	5,780,290	6,002,921	4,371,691	4,852,417	3,499,039	6,208,143	21,912,465	18,931,290
Operating Income	676,214	1,868,781	2,119,797	2,325,460	1,657,368	2,126,417	530,520	3,138,149	6,990,252	7,452,453
Net Income (Loss)	$ 64,698	$ 1,197,877	$ 1,247,305	$ 3,143,417	$ 2,108,890	$ 1,426,090	$ 228,837	$ 2,075,570	$ 5,653,298	$ 5,839,387
Net Income Per Common Share - Basic (in dollars per share)	$ 0.02	$ 0.35	$ 0.37	$ 0.93	$ 0.63	$ 0.43	$ 0.07	$ 0.63	$ 1.66	$ 1.76
Net Income Per Common Share - Diluted (in dollars per share)	$ 0.02	$ 0.35	$ 0.37	$ 0.93	$ 0.63	$ 0.43	$ 0.07	$ 0.63	$ 1.66	$ 1.76