Property and Equipment (Details) (USD $)	6 Months Ended
	Jun. 30, 2014	Dec. 31, 2013
Components of property and equipment
Property and equipment, gross	$ 102,390,106	$ 96,438,747
Less: accumulated depreciation	(29,562,448)	(25,843,609)
Property and equipment, net	72,827,658	70,595,138
Office equipment and furniture [Member]
Components of property and equipment
Property and equipment, useful life	5 years
Property and equipment, gross	161,655	156,810
Manufacturing equipment [Member]
Components of property and equipment
Property and equipment, gross	74,509,161	74,187,972
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	205,156	129,380
Construction in progress [Member]
Components of property and equipment
Property and equipment, useful life	0 years
Property and equipment, gross	3,173,902	477,299
Building and building improvements [Member]
Components of property and equipment
Property and equipment, useful life	20 years
Property and equipment, gross	$ 24,340,232	$ 21,487,286