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Pension and Post-Employment Benefits - Fair Value of Pension Assets (Detail) - USD ($) $ in Millions | Dec. 31, 2024 | Dec. 31, 2023
--- | --- | ---
Fair value of pension assets |  |
Total plan assets | $ 2.4 | $ 35.1
Non-US [Member] |  |
Fair value of pension assets |  |
Debt securities |  | 443.4
Cash | 2.5 | 15.8
Total plan assets | 2.5 | 459.2
Non-US [Member] | Debt Securities Issued by Non-U.S. Government and Government Agencies [Member] |  |
Fair value of pension assets |  |
Debt securities |  | 4.7
Non-US [Member] | Insurance Contracts [Member] |  |
Fair value of pension assets |  |
Debt securities |  | 438.7
Non-US [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] |  |
Fair value of pension assets |  |
Debt securities |  | 4.7
Cash | 2.5 | 15.8
Total plan assets | 2.5 | 20.5
Non-US [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Debt Securities Issued by Non-U.S. Government and Government Agencies [Member] |  |
Fair value of pension assets |  |
Debt securities |  | 4.7
Non-US [Member] | Significant Other Observable Inputs (Level 2) [Member] |  |
Fair value of pension assets |  |
Debt securities |  | 0.0
Total plan assets | 0.0 | 0.0
Non-US [Member] | Significant Unobservable Inputs (Level 3) [Member] |  |
Fair value of pension assets |  |
Debt securities |  | 438.7
Total plan assets | $ 0.0 | 438.7
Non-US [Member] | Significant Unobservable Inputs (Level 3) [Member] | Insurance Contracts [Member] | Other Asset Backed Securitites [Member] |  |
Fair value of pension assets |  |
Debt securities |  | $ 438.7

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