Derivatives and Fair Value Measurements - Location and Fair Value Amount of Derivative Instruments (Detail) - USD ($) $ in Millions	Jun. 30, 2022	Dec. 31, 2021
Derivatives Fair Value [Line Items]
Asset Derivatives, Fair Value	$ 20.4	$ 13.2
Liability Derivatives, Fair Value	26.9	36.5
Derivatives Not Designated as Hedging Instruments under ASC 815 [Member] | Metal Commodity Contracts [Member] | Prepaid Expenses and Other Current Assets [Member]
Derivatives Fair Value [Line Items]
Asset Derivatives, Fair Value	19.3	13.0
Derivatives Not Designated as Hedging Instruments under ASC 815 [Member] | Metal Commodity Contracts [Member] | Other Accrued Liabilities [Member]
Derivatives Fair Value [Line Items]
Liability Derivatives, Fair Value	26.9	35.1
Derivatives Not Designated as Hedging Instruments under ASC 815 [Member] | Diesel Fuel Commodity Contracts [Member] | Prepaid Expenses and Other Current Assets [Member]
Derivatives Fair Value [Line Items]
Asset Derivatives, Fair Value	0.8
Derivatives Not Designated as Hedging Instruments under ASC 815 [Member] | 2028 Notes Embedded Derivative [Member] | Prepaid Expenses and Other Current Assets [Member]
Derivatives Fair Value [Line Items]
Asset Derivatives, Fair Value		0.2
Derivatives Not Designated as Hedging Instruments under ASC 815 [Member] | Interest Rate Swaps [Member] | Prepaid Expenses and Other Current Assets [Member]
Derivatives Fair Value [Line Items]
Asset Derivatives, Fair Value	$ 0.3
Derivatives Not Designated as Hedging Instruments under ASC 815 [Member] | Interest Rate Swaps [Member] | Other Accrued Liabilities [Member]
Derivatives Fair Value [Line Items]
Liability Derivatives, Fair Value		$ 1.4