Note 17 - Segment and Related Information - Geographical Information (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
Sales	$ 21,103,124	$ 22,244,681	$ 24,514,636	$ 21,836,087	$ 21,135,277	$ 19,771,137	$ 13,593,192	$ 11,878,700	$ 89,698,527	$ 66,378,306
UNITED STATES
Sales									89,370,005	64,874,554
CANADA
Sales									283,011	351,211
CHINA
Sales									23,134
MEXICO
Sales										53,246
POLAND
Sales									1,750	10,299
PERU
Sales									12,202
Other Foreign Countries [Member]
Sales									$ 8,425	$ 1,088,996