Annual report pursuant to Section 13 and 15(d)

Property, Plant and Equipment (Details)

v3.8.0.1
Property, Plant and Equipment (Details) - USD ($)
 12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Property, Plant and Equipment [Line Items]      
Total property, plant and equipment, gross $ 85,531,445 $ 72,543,401  
Less accumulated depreciation 50,451,436 45,219,309  
Property, plant and equipment, net 35,080,009 27,324,092  
Depreciation expense 5,294,695 4,235,203 $ 4,356,911
Capital Leases, Lessee Balance Sheet, Assets by Major Class, Accumulated Depreciation 86,357 25,341  
Land [Member]      
Property, Plant and Equipment [Line Items]      
Total property, plant and equipment, gross 62,916 62,916  
Land improvements [Member]      
Property, Plant and Equipment [Line Items]      
Total property, plant and equipment, gross 544,186 120,915  
Building [Member]      
Property, Plant and Equipment [Line Items]      
Total property, plant and equipment, gross 412,301 641,526  
Machinery, fixtures and equipment [Member]      
Property, Plant and Equipment [Line Items]      
Total property, plant and equipment, gross 81,229,311 66,099,880  
Machinery and equipment under capital lease      
Property, Plant and Equipment [Line Items]      
Total property, plant and equipment, gross 401,077 199,767  
Construction-in-progress [Member]      
Property, Plant and Equipment [Line Items]      
Total property, plant and equipment, gross $ 2,881,654 $ 5,418,397