Contingencies and Legal Matters (Details)	6 Months Ended
	Jun. 30, 2020 employee
Workforce Subject to Collective Bargaining Arrangements Expiring within One Year
Concentrations
Number of Employees	384
IG BCE | Germany | Workforce Subject to Collective Bargaining Arrangements
Concentrations
Percentage of salaried employees eligible to be represented by Mining, Chemicals and Energy Trade Union (IG BCE)	50.00%
Percentage of hourly employees eligible to be represented by Mining, Chemicals and Energy Trade Union (IG BCE)	80.00%
USW | Whiting, WI | January 2021 | Workforce Subject to Collective Bargaining Arrangements Expiring within One Year
Concentrations
Number of Employees	201
USW | Neenah, WI | June 2021 | Workforce Subject to Collective Bargaining Arrangements Expiring within One Year
Concentrations
Number of Employees	183
USW | Munising, MI | July 2021 | Workforce Subject to Collective Bargaining Arrangements
Concentrations
Number of Employees	180
USW | Lowville, NY | November 2021 | Workforce Subject to Collective Bargaining Arrangements
Concentrations
Number of Employees	94
USW | Appleton, WI | May 2022 | Workforce Subject to Collective Bargaining Arrangements
Concentrations
Number of Employees	84