Quarterly report pursuant to Section 13 or 15(d)

Inventories (Details)

v3.19.2
Inventories (Details) - USD ($)
Jun. 30, 2019
Dec. 31, 2018
Inventory Disclosure [Abstract]    
Raw materials $ 55,329,614 $ 59,778,767
Work-in-process 17,768,751 21,033,532
Finished goods 37,317,877 33,389,087
Total inventories $ 110,416,242 $ 114,201,386