Inventories, net - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Inventories, net additional information
Charges to cost of sales due to lower of cost or market value	$ 3.7	$ 2.8	$ 2.2
Inventory on consignment at customer locations	4.9	5.0
Inventory reserves
Inventories, net additional information
Increase in inventory reserves	0.1
Inventory reserves	$ 8.3	$ 8.2