Property and Equipment (Details) - USD ($)	3 Months Ended
	Mar. 31, 2017	Dec. 31, 2016
Components of property and equipment
Property and equipment, gross	$ 54,018,165	$ 53,610,710
Less: accumulated depreciation	(24,879,267)	(23,732,035)
Property and equipment, net	$ 29,138,898	29,878,675
Office equipment and furniture [Member]
Components of property and equipment
Property and equipment, useful life	5 years
Property and equipment, gross	$ 67,146	65,209
Manufacturing equipment [Member]
Components of property and equipment
Property and equipment, gross	$ 32,484,174	32,240,010
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	$ 171,059	169,773
Building and building improvements [Member]
Components of property and equipment
Property and equipment, gross	$ 21,295,786	$ 21,135,718
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