Annual report pursuant to Section 13 and 15(d)

Contingencies - Sales to Major Customers (Details)

v3.10.0.1
Contingencies - Sales to Major Customers (Details) - Customer concentration risk - Sales Revenue, Net
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Company A      
Product Information [Line Items]      
Percentage of sales to major customers 17.00% 40.00% 59.00%
Company B      
Product Information [Line Items]      
Percentage of sales to major customers 10.00%   12.00%
Company C      
Product Information [Line Items]      
Percentage of sales to major customers     10.00%