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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 | Jun. 30, 2023 | Dec. 31, 2022
--- | --- | ---
Carrying Amount [Member] |  |
Non-derivatives: |  |
Cash and cash equivalents | $ 165.9 | $ 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 | 0.3 | 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 | 2.0 | 2.7
Carrying Amount [Member] | Significant Unobservable Inputs (Level 3) [Member] |  |
Non-financial liabilities (Level 3 measurement): |  |
Stock equivalent units | 16.9 | 26.4
Fair Value [Member] |  |
Non-derivatives: |  |
Cash and cash equivalents | 165.9 | 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 | 0.3 | 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 | 2.0 | 2.7
Fair Value [Member] | Significant Unobservable Inputs (Level 3) [Member] |  |
Non-financial liabilities (Level 3 measurement): |  |
Stock equivalent units | $ 16.9 | $ 26.4

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- Definition Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. + References No definition available. + Details
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