Property, Plant and Equipment - Additional Information (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Property Plant And Equipment [Line Items]
Depreciation expense	$ 3,389,814	$ 3,085,140	$ 6,658,713	$ 6,081,309
Product
Property Plant And Equipment [Line Items]
Cost of goods sold, depreciation	$ 1,498,334	$ 1,448,015	$ 2,989,329	$ 2,881,632