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Employee Benefits - Summary of Total Expense Related to All Postretirement Benefit Plans (Details) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2025 | Sep. 30, 2024 | Sep. 30, 2025 | Sep. 30, 2024
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Net periodic postretirement and postemployment benefit cost relating to defined benefit plans | $ 1.2 | $ 1.5 | $ 3.8 | $ 3.3
Postretirement and Postemployment Benefit Plans |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Defined contribution plan, cost | 4.2 | 4.4 | 14.8 | 14.4
Deferred compensation arrangement with individual, compensation expense | 0.5 | 0.5 | 1.1 | 1.2
Multiemployer plan, contributions by employer | 1.6 | 1.6 | 4.7 | 4.6
Net periodic postretirement and postemployment benefit cost relating to defined benefit plans | 2.3 | 2.5 | 7.1 | 6.8
Total other employee benefit plans | $ 8.6 | $ 9.0 | $ 27.7 | $ 27.0

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