Fair Value Measurements - Carrying Amount and Fair Values of the Company's Assets and Liabilities Measured on a Recurring Basis (Detail) - Recurring [Member] - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Carrying Amount [Member]
Non-derivatives:
Cash and cash equivalents	$ 147.5	$ 147.1
Carrying Amount [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Foreign Currency Forward Exchange Contracts [Member]
Derivatives (Level 1 measurement):
Foreign currency forward exchange contracts	0.8	0.5
Carrying Amount [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Emission Trading Scheme Credits [Member]
Derivatives (Level 1 measurement):
Emissions Trading Scheme credits	2.5	2.7
Carrying Amount [Member] | Significant Unobservable Inputs (Level 3) [Member]
Non-financial liabilities (Level 3 measurement):
Stock equivalent units	16.6	26.4
Fair Value [Member]
Non-derivatives:
Cash and cash equivalents	147.5	147.1
Fair Value [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Foreign Currency Forward Exchange Contracts [Member]
Derivatives (Level 1 measurement):
Foreign currency forward exchange contracts	0.8	0.5
Fair Value [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Emission Trading Scheme Credits [Member]
Derivatives (Level 1 measurement):
Emissions Trading Scheme credits	2.5	2.7
Fair Value [Member] | Significant Unobservable Inputs (Level 3) [Member]
Non-financial liabilities (Level 3 measurement):
Stock equivalent units	$ 16.6	$ 26.4