Property and Equipment (Details) - USD ($)	6 Months Ended
	Jun. 30, 2015	Dec. 31, 2014
Components of property and equipment
Property and equipment, gross	$ 104,175,136	$ 103,326,097
Less: accumulated depreciation	(38,133,408)	(33,697,500)
Property and equipment, net	$ 66,041,728	69,628,597
Office equipment and furniture [Member]
Components of property and equipment
Property and equipment, useful life	5 years
Property and equipment, gross	$ 172,886	166,734
Manufacturing equipment [Member]
Components of property and equipment
Property and equipment, gross	$ 77,498,325	76,870,025
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	$ 207,393	205,714
Building and building improvements [Member]
Components of property and equipment
Property and equipment, gross	$ 26,296,532	$ 26,083,624
Building and building improvements [Member] | Minimum [Member]
Components of property and equipment
Property and equipment, useful life	5 years
Building and building improvements [Member] | Maximum [Member]
Components of property and equipment
Property and equipment, useful life	20 years