Property, plant and equipment (Details) (USD $)			12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013 Building and Improvements [Member]	Dec. 31, 2013 Manufacturing and warehouse equipment [Member] Minimum [Member]	Dec. 31, 2013 Manufacturing and warehouse equipment [Member] Maximum [Member]	Dec. 31, 2013 Office equipment and furniture [Member] Minimum [Member]	Dec. 31, 2013 Office equipment and furniture [Member] Maximum [Member]	Dec. 31, 2013 Leasehold improvements [Member] Minimum [Member]	Dec. 31, 2013 Leasehold improvements [Member] Maximum [Member]	Dec. 31, 2013 Automobile [Member]
Summary of property, plant and equipment
Land	$ 278,325	$ 278,325
Building and Improvements	4,632,565	4,489,377
Manufacturing and warehouse equipment	8,160,173	7,982,669
Office equipment and furniture	830,950	738,584
Construction in process	19,604	249,027
Leasehold improvements	419,315	122,644
Automobile	32,263
Property, plant and equipment, gross	14,373,195	13,860,626
Less accumulated depreciation	9,256,754	8,532,717
Property, plant and equipment, net	$ 5,116,441	$ 5,327,909
Estimated Useful Life			30 years	6 years	20 years	3 years	5 years	10 years	15 years	3 years