v3.26.1
Derivatives, Hedging Programs and Other Financial Instruments - Summary of (Gain) Loss Associated with Derivative Contracts (Details) - USD ($)
$ in Millions
 3 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Derivative Instruments Gain Loss [Line Items]    
Total of income and expense line items presented in our Statements of Consolidated Income in which the effects of cash flow hedges are recorded $ 943.2 $ 673.4
Cash Flow Hedges    
Derivative Instruments Gain Loss [Line Items]    
Total of income and expense line items presented in our Statements of Consolidated Income in which the effects of cash flow hedges are recorded 943.2 673.4
Cash Flow Hedges | Designated as Hedging Instrument    
Derivative Instruments Gain Loss [Line Items]    
Total gain recognized in our Statements of Consolidated Income related to cash flow hedges $ (9.3) $ (5.5)
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 in which the effects of cash flow hedges are recorded Total of income and expense line items presented in our Statements of Consolidated Income in which the effects of cash flow hedges are recorded
Cash Flow Hedges | Designated as Hedging Instrument | Aluminum    
Derivative Instruments Gain Loss [Line Items]    
Total gain recognized in our Statements of Consolidated Income related to cash flow hedges $ (8.5) $ (5.2)
Cash Flow Hedges | Designated as Hedging Instrument | Alloying Metals    
Derivative Instruments Gain Loss [Line Items]    
Total gain recognized in our Statements of Consolidated Income related to cash flow hedges (0.5) (0.4)
Cash Flow Hedges | Designated as Hedging Instrument | Foreign exchange contracts    
Derivative Instruments Gain Loss [Line Items]    
Total gain recognized in our Statements of Consolidated Income related to cash flow hedges   $ 0.1
Cash Flow Hedges | Designated as Hedging Instrument | Natural Gas    
Derivative Instruments Gain Loss [Line Items]    
Total gain recognized in our Statements of Consolidated Income related to cash flow hedges $ (0.3)