Note 12 - Segment Information - Net Sales for Geographic Areas (Details) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Net sales	$ 24,100,498	$ 18,628,362	$ 19,552,905	$ 20,672,227	$ 24,292,971	$ 19,355,937	$ 19,773,528	$ 20,788,764	$ 82,923,992	$ 84,161,200	$ 83,430,912
UNITED STATES
Net sales									70,886,401	72,061,009	69,791,099
CANADA
Net sales									7,199,155	7,543,468	8,342,896
All Other Countries [Member]
Net sales									$ 4,838,436	$ 4,556,723	$ 5,296,917