Quarterly report pursuant to Section 13 or 15(d)

Major Customers and Vendors (Details)

v3.10.0.1
Major Customers and Vendors (Details)
 3 Months Ended 9 Months Ended 12 Months Ended
Sep. 30, 2018
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Sep. 30, 2017
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Sep. 30, 2018
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Sep. 30, 2017
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Dec. 31, 2017
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Purchases | Vendor concentration risk          
Significant Customers and Vendors          
Number of vendors | item 2 2 2 2  
Purchases | Vendor concentration risk | Major vendor one          
Significant Customers and Vendors          
Percentage of concentration risk 22.60% 27.90% 25.10% 27.00%  
Purchases | Vendor concentration risk | Major vendor two          
Significant Customers and Vendors          
Percentage of concentration risk 15.20% 14.10% 14.80% 14.10%  
Net sales | Customer concentration risk          
Significant Customers and Vendors          
Number of customers 2 2 2 2  
Net sales | Customer one | Customer concentration risk          
Significant Customers and Vendors          
Percentage of concentration risk 37.30% 20.80% 27.50% 20.30%  
Net sales | Customer two | Customer concentration risk          
Significant Customers and Vendors          
Percentage of concentration risk 15.60% 17.20% 16.50% 17.90%  
Net accounts receivable | Customer concentration risk          
Significant Customers and Vendors          
Number of customers     2   2
Net accounts receivable | Customer one | Customer concentration risk          
Significant Customers and Vendors          
Percentage of concentration risk     40.60%   28.60%
Net accounts receivable | Customer two | Customer concentration risk          
Significant Customers and Vendors          
Percentage of concentration risk     8.80%   15.10%