Property and Equipment (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Components of property and equipment
Property and equipment, gross	$ 96,438,747	$ 78,079,102
Less: accumulated depreciation	(25,843,609)	(18,643,002)
Property and equipment, net	70,595,138	59,436,100
Office equipment and furniture [Member]
Components of property and equipment
Property and equipment, useful life	5 years
Property and equipment, gross	156,810	222,853
Manufacturing equipment [Member]
Components of property and equipment
Property and equipment, gross	74,187,972	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	129,380	125,167
Construction in progress [Member]
Components of property and equipment
Property and equipment, useful life	0 years
Property and equipment, gross	477,299	28,785
Building and building improvements [Member]
Components of property and equipment
Property and equipment, useful life	20 years
Property and equipment, gross	$ 21,487,286	$ 20,785,597