Revenue - Sales to Major Customers (Details)	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Total Net Sales \| Customer concentration \| Two Customers
Major Customers and Suppliers
Concentration risk	26.00%	28.00%	20.00%

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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