Note 1 - Nature of Business and Significant Accounting Policies - Adoption of ASU No. 2014-09, Results from Operations (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Net sales	$ 36,115,741	$ 41,788,782
Net loss	(1,903,341)	$ (696,912)
Calculated under Revenue Guidance in Effect before Topic 606 [Member]
Net sales	36,086,633
Net loss	(1,932,449)
Difference between Revenue Guidance in Effect before and after Topic 606 [Member]
Net sales	29,108
Net loss	$ 29,108