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Income Taxes - Roll-forward of Unrecognized Tax Benefits and Associated Accrued Interest and Penalties (Detail) - USD ($) $ in Millions | 3 Months Ended |
--- | --- | ---
Mar. 31, 2024 | Dec. 31, 2023
Income Tax Contingency [Line Items] |  |
Opening balance at January 1 | $ 14.8 |
Net change for tax positions of prior periods | 0.2 |
Closing balance at March 31 | 15.0 |
Current | (4.5) | $ (1.2)
Non-current | 10.5 | $ 13.6
Interest and Penalties [Member] |  |
Income Tax Contingency [Line Items] |  |
Opening balance at January 1 | 4.3 |
Net change for tax positions of prior periods | 0.3 |
Closing balance at March 31 | 4.6 |
Current | (1.3) |
Non-current | 3.3 |
Unrecognized Tax Benefits [Member] |  |
Income Tax Contingency [Line Items] |  |
Opening balance at January 1 | 10.5 |
Net change for tax positions of prior periods | (0.1) |
Closing balance at March 31 | 10.4 |
Current | (3.2) |
Non-current | $ 7.2 |

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