Derivatives and Fair Value Measurements - Location and Amount of Gains and Losses on Derivatives Not Designated as Hedging Instruments Reported in Condensed Consolidated Statements of Comprehensive Income (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Derivative Instruments Gain Loss [Line Items]
Amount of Gain/ (Loss) Recognized in Income on Derivatives	$ 10.3	$ (9.1)
Derivatives Not Designated as Hedging Instruments under ASC 815 [Member]
Derivative Instruments Gain Loss [Line Items]
Amount of Gain/ (Loss) Recognized in Income on Derivatives	(1.5)	(10.3)
Amount of Gain/ (Loss) Reclassified from Other Comprehensive Income into Income	(0.7)	(0.5)
Derivatives Not Designated as Hedging Instruments under ASC 815 [Member] | Metal Commodity Contracts [Member] | Cost of Materials Sold [Member]
Derivative Instruments Gain Loss [Line Items]
Amount of Gain/ (Loss) Recognized in Income on Derivatives	(2.6)	(10.7)
Derivatives Not Designated as Hedging Instruments under ASC 815 [Member] | Diesel Fuel Commodity Contracts [Member] | Warehousing, Delivery, Selling, General, and Administrative [Member]
Derivative Instruments Gain Loss [Line Items]
Amount of Gain/ (Loss) Recognized in Income on Derivatives	0.7
Derivatives Not Designated as Hedging Instruments under ASC 815 [Member] | 2028 Notes Embedded Derivative [Member] | Other Income and (Expense), Net [Member]
Derivative Instruments Gain Loss [Line Items]
Amount of Gain/ (Loss) Recognized in Income on Derivatives	(0.2)	0.3
Derivatives Not Designated as Hedging Instruments under ASC 815 [Member] | Foreign Exchange Contracts [Member] | Other Income and (Expense), Net [Member]
Derivative Instruments Gain Loss [Line Items]
Amount of Gain/ (Loss) Recognized in Income on Derivatives		0.1
Derivatives Not Designated as Hedging Instruments under ASC 815 [Member] | Interest Rate Swaps [Member] | Interest and Other Expense on Debt [Member]
Derivative Instruments Gain Loss [Line Items]
Amount of Gain/ (Loss) Recognized in Income on Derivatives	0.6
Amount of Gain/ (Loss) Reclassified from Other Comprehensive Income into Income	$ (0.7)	$ (0.5)