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v3.25.4

Postretirement Health Care and Life Insurance Benefits - Net Periodic Postretirement Benefit Cost (Details) - Postretirement Health Care and Life Insurance Benefits - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2025 | Dec. 31, 2024 | Dec. 31, 2023
Defined Benefit Plan Disclosure [Line Items] |  |  |
Service cost | $ 0.3 | $ 0.5 | $ 0.5
Interest cost | 7.8 | 9.1 | 10.2
Expected return on plan assets | (0.3) | (0.4) | (0.5)
Amortization of prior service credit | (40.8) | (53.0) | (53.8)
Net actuarial gain | (8.5) | (17.0) | (2.6)
Net periodic postretirement benefit credit | $ (41.5) | $ (60.8) | $ (46.2)

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