Property and Equipment (Details) (USD $)	9 Months Ended
	Sep. 30, 2013	Dec. 31, 2012
Components of property and equipment
Property and equipment, gross	$ 90,779,808	$ 78,079,102
Less: accumulated depreciation	(24,080,717)	(18,643,002)
Property and equipment, net	66,699,091	59,436,100
Office equipment and furniture [Member]
Components of property and equipment
Property and equipment, useful life	5 years
Property and equipment, gross	253,404	222,853
Manufacturing equipment [Member]
Components of property and equipment
Property and equipment, gross	67,477,040	56,916,700
Manufacturing equipment [Member] | Minimum [Member]
Components of property and equipment
Property and equipment, useful life	5 years
Manufacturing equipment [Member] | Maximum [Member]
Components of property and equipment
Property and equipment, useful life	10 years
Vehicles [Member]
Components of property and equipment
Property and equipment, useful life	5 years
Property and equipment, gross	128,518	125,167
Construction in progress [Member]
Components of property and equipment
Property and equipment, gross	1,578,728	28,785
Building and building improvements [Member]
Components of property and equipment
Property and equipment, useful life	20 years
Property and equipment, gross	$ 21,342,118	$ 20,785,597