Annual report pursuant to Section 13 and 15(d)

Contingencies - Sales to Major Customers (Details)

v3.20.4
Contingencies - Sales to Major Customers (Details) - Customer concentration risk - Revenue
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Company A      
Product Information [Line Items]      
Percentage of sales to major customers 12.00% 14.00% 17.00%
Company B      
Product Information [Line Items]      
Percentage of sales to major customers     10.00%