Derivatives, Hedging Programs and Other Financial Instruments - Summary of Derivative Positions (Details) Mmlb in Millions	3 Months Ended
	Mar. 31, 2023 Mmlb EUR (€) MMBTU GBP (£)
Purchase | Euro
Derivative [Line Items]
Derivative non-monetary notional amount | €	690,816
Purchase | British Pounds
Derivative [Line Items]
Derivative non-monetary notional amount | £	202,128
Purchase | Minimum | Euro
Derivative [Line Items]
Derivative maturity period	Jul. 31, 2023
Purchase | Minimum | British Pounds
Derivative [Line Items]
Derivative maturity period	May 31, 2023
Purchase | Maximum | Euro
Derivative [Line Items]
Derivative maturity period	Feb. 29, 2024
Purchase | Maximum | British Pounds
Derivative [Line Items]
Derivative maturity period	Sep. 30, 2023
Purchase | Natural Gas
Derivative [Line Items]
Derivative non-monetary notional amount | MMBTU	3,780,000
Purchase | Natural Gas | Minimum
Derivative [Line Items]
Derivative maturity period	Apr. 30, 2023
Purchase | Natural Gas | Maximum
Derivative [Line Items]
Derivative maturity period	Dec. 31, 2026
Purchase | Aluminum
Derivative [Line Items]
Derivative non-monetary notional amount	63.4
Purchase | Aluminum | Minimum
Derivative [Line Items]
Derivative maturity period	Apr. 30, 2023
Purchase | Aluminum | Maximum
Derivative [Line Items]
Derivative maturity period	Jul. 31, 2024
Purchase | Midwest premium purchase contracts
Derivative [Line Items]
Derivative non-monetary notional amount	74.4
Purchase | Midwest premium purchase contracts | Minimum
Derivative [Line Items]
Derivative maturity period	Apr. 30, 2023
Purchase | Midwest premium purchase contracts | Maximum
Derivative [Line Items]
Derivative maturity period	Jul. 31, 2024
Purchase | Alloying Metals
Derivative [Line Items]
Derivative non-monetary notional amount	0.9
Purchase | Alloying Metals | Minimum
Derivative [Line Items]
Derivative maturity period	Apr. 30, 2023
Purchase | Alloying Metals | Maximum
Derivative [Line Items]
Derivative maturity period	Dec. 31, 2023
Sales | Midwest premium sale contracts
Derivative [Line Items]
Derivative non-monetary notional amount	21.0
Sales | Midwest premium sale contracts | Minimum
Derivative [Line Items]
Derivative maturity period	Jul. 31, 2023
Sales | Midwest premium sale contracts | Maximum
Derivative [Line Items]
Derivative maturity period	Sep. 30, 2023