v3.26.1
Derivatives and Fair Value Measurements - Location and Fair Value Amount of Derivative Instruments (Detail) - Level 2 [Member] - USD ($)
$ in Millions
Jun. 30, 2026
Dec. 31, 2025
Derivatives Fair Value [Line Items]    
Asset Derivatives, Fair Value $ 21.0 $ 12.2
Liability Derivatives, Fair Value 22.1 12.5
Derivatives Not Designated as Hedging Instruments under ASC 815 [Member] | Metal Commodity Contracts [Member]    
Derivatives Fair Value [Line Items]    
Asset Derivatives, Fair Value $ 19.8 $ 12.2
Derivative Asset, Statement of Financial Position [Extensible Enumeration] Prepaid Expense and Other Assets, Current Prepaid Expense and Other Assets, Current
Derivatives Not Designated as Hedging Instruments under ASC 815 [Member] | Metal Commodity Contracts [Member] | Location, Statement of Financial Position, Balance [Axis]: us-gaap:OtherAccruedLiabilitiesCurrent    
Derivatives Fair Value [Line Items]    
Liability Derivatives, Fair Value $ 8.1 $ 2.6
Derivatives Not Designated as Hedging Instruments under ASC 815 [Member] | Energy Commodity Contracts [Member]    
Derivatives Fair Value [Line Items]    
Asset Derivatives, Fair Value $ 1.1  
Derivative Asset, Statement of Financial Position [Extensible Enumeration] Prepaid Expense and Other Assets, Current  
Derivatives Not Designated as Hedging Instruments under ASC 815 [Member] | Energy Commodity Contracts [Member] | Location, Statement of Financial Position, Balance [Axis]: us-gaap:OtherAccruedLiabilitiesCurrent    
Derivatives Fair Value [Line Items]    
Liability Derivatives, Fair Value   0.2
Derivatives Not Designated as Hedging Instruments under ASC 815 [Member] | Embedded Customer Derivatives [Member] | Location, Statement of Financial Position, Balance [Axis]: us-gaap:OtherAccruedLiabilitiesCurrent    
Derivatives Fair Value [Line Items]    
Liability Derivatives, Fair Value $ 14.0 $ 9.7
Derivatives Not Designated as Hedging Instruments under ASC 815 [Member] | Foreign Currency Exchange Contracts [Member]    
Derivatives Fair Value [Line Items]    
Asset Derivatives, Fair Value $ 0.1  
Derivative Asset, Statement of Financial Position [Extensible Enumeration] Prepaid Expense and Other Assets, Current