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Pension and Post-Employment Benefits - Reconciliation of Fair Value of Plan Assets Measured Using Significant Unobservable Inputs (Detail) - United Kingdom Plan [Member] - Significant Unobservable Inputs (Level 3) [Member] - Other Assets [Member] - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2024 | Dec. 31, 2023
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |  |
Beginning balance | $ 438.7 | $ 431.8
Realized/unrealized gains/(losses): |  |
Relating to assets still held at the reporting date | (2.2) | 16.9
Purchases, issuances and settlements | (438.8) | (33.7)
Exchange effect | 2.3 | 23.7
Ending balance | $ 0.0 | $ 438.7

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