Note 7 - Segment Information (Details) - Net sales for geographic areas: (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Revenues from External Customers and Long-Lived Assets [Line Items]
Geographic locations	$ 18,524,604	$ 17,000,728	$ 56,735,444	$ 52,082,061
United States [Member] | Three Months [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Geographic locations			15,466,317	14,221,642
United States [Member] | Nine Months [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Geographic locations			47,404,281	43,861,288
Canada [Member] | Three Months [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Geographic locations			1,889,696	1,761,960
Canada [Member] | Nine Months [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Geographic locations			5,728,405	5,214,782
All Other Countries [Member] | Three Months [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Geographic locations			1,168,591	1,017,126
All Other Countries [Member] | Nine Months [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Geographic locations			3,602,758	3,005,991
Three Months [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Geographic locations			18,524,604	17,000,728
Nine Months [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Geographic locations			$ 56,735,444	$ 52,082,061