Note 15 - Segment Information - Summary of Geographic Area Data (Details) - USD ($)		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017
Net sales		$ 36,115,741	$ 41,788,782
Assets by area		16,353,865	21,075,996
UNITED STATES
Net sales		27,673,352	32,474,797
Assets by area		13,584,424	18,100,872
Australia, New Zealand [Member]
Net sales		732,227	922,594
Assets by area		540,591	572,368
CANADA
Net sales		718,560	914,775
Assets by area		166,533	265,629
MEXICO
Net sales		474,372	445,299
Assets by area		179,713	219,501
Europe [Member]
Net sales	[1]	3,972,381	4,578,095
Assets by area	[1]	867,008	1,032,641
Asia [Member]
Net sales	[2]	2,544,849	2,453,222
Assets by area	[2]	$ 1,015,596	$ 884,985

[1] Europe consists of United Kingdom, Ireland, France, Germany, Austria, and the Netherlands.

[2] Asia consists of Philippines, Malaysia, and Singapore.