The aggregate costs related to goods produced and sold and services rendered by an entity during the reporting period. This excludes costs incurred during the reporting period related to financial services rendered and other revenue generating activities.

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Derivatives, Hedging Programs and Other Financial Instruments - Summary of Loss (Gain) Associated with Derivative Contracts (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Derivative Instruments Gain Loss [Line Items]
Total of income and expense line items presented in our Statements of Consolidated Income (Loss) in which the effects of cash flow hedges are recorded	$ 718.4	$ 898.4	$ 1,449.5	$ 1,764.3
Derivative, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Total of income and expense line items presented in our Statements of Consolidated Income (Loss) in which the effects of cash flow hedges are recorded	Total of income and expense line items presented in our Statements of Consolidated Income (Loss) in which the effects of cash flow hedges are recorded	Total of income and expense line items presented in our Statements of Consolidated Income (Loss) in which the effects of cash flow hedges are recorded	Total of income and expense line items presented in our Statements of Consolidated Income (Loss) in which the effects of cash flow hedges are recorded
Not Designated as Hedging Instrument
Derivative Instruments Gain Loss [Line Items]
Loss (gain) recognized in our Statements of Consolidated Income (Loss)	$ 0.2	$ 2.4	$ 0.1	$ 0.8
Not Designated as Hedging Instrument \| Alloying Metals
Derivative Instruments Gain Loss [Line Items]
Loss (gain) recognized in our Statements of Consolidated Income (Loss)		(0.5)		(1.1)
Loss (gain) recognized in our Statements of Consolidated Income (Loss) Unrealized loss	0.2	2.9	0.1	1.9
Cash Flow Hedges
Derivative Instruments Gain Loss [Line Items]
Total of income and expense line items presented in our Statements of Consolidated Income (Loss) in which the effects of cash flow hedges are recorded	718.4	898.4	1,449.5	1,764.3
Cash Flow Hedges \| Designated as Hedging Instrument
Derivative Instruments Gain Loss [Line Items]
Loss (gain) recognized in our Statements of Consolidated Income (Loss)	5.5	2.9	5.7	(17.0)
Cash Flow Hedges \| Designated as Hedging Instrument \| Electricity
Derivative Instruments Gain Loss [Line Items]
Loss (gain) recognized in our Statements of Consolidated Income (Loss)		(1.1)		(1.4)
Cash Flow Hedges \| Designated as Hedging Instrument \| Natural Gas
Derivative Instruments Gain Loss [Line Items]
Loss (gain) recognized in our Statements of Consolidated Income (Loss)	0.3	(1.9)		(2.8)
Cash Flow Hedges \| Designated as Hedging Instrument \| Aluminum
Derivative Instruments Gain Loss [Line Items]
Loss (gain) recognized in our Statements of Consolidated Income (Loss)	$ 5.2	$ 5.9	$ 5.7	$ (12.8)