Derivatives, Hedging Programs and Other Financial Instruments - Summary of Percentage of Expected Variable Priced Purchases of Metals Alloys and Energy (Details) - Scenario, Forecast	Dec. 31, 2026	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Zinc
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount, Percent of Required Need, Coverage				11.00%
Copper
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount, Percent of Required Need, Coverage				19.00%
Magnesium
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount, Percent of Required Need, Coverage		27.00%	67.00%	98.00%
Silicon
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount, Percent of Required Need, Coverage				100.00%
Natural Gas
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount, Percent of Required Need, Coverage	19.00%	23.00%	42.00%	44.00%
Electricity
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount, Percent of Required Need, Coverage				56.00%