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Retirement and Postretirement Plans - Allocation of Plan Assets (Details) - USD ($) $ in Millions | 12 Months Ended |
--- | --- | ---
Dec. 31, 2024 | Dec. 31, 2023 | Dec. 31, 2022
Pension |  |  |
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Total Assets | $ 396.6 | $ 525.6 | $ 549.4
Pension | Level 1, 2 and 3 |  |  |
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Total Assets | 205.5 | 251.9 |
Pension | Level 1, 2 and 3 | Cash and cash equivalents |  |  |
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Total Assets | 12.6 | 5.8 |
Pension | Level 1, 2 and 3 | U.S government and agency securities |  |  |
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Total Assets | 36.3 | 59.8 |
Pension | Level 1, 2 and 3 | Corporate bonds |  |  |
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Total Assets |  | 39.8 |
Pension | Level 1, 2 and 3 | Mutual fund - equities |  |  |
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Total Assets | 80.9 | 83.3 |
Pension | Level 1, 2 and 3 | Mutual fund - fixed income |  |  |
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Total Assets | 12.5 | 12.2 |
Pension | Level 1, 2 and 3 | Mutual fund - tactical tilt |  |  |
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Total Assets | 10.8 | 10.6 |
Pension | Level 1, 2 and 3 | Equity securities |  |  |
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Total Assets | 0.5 |  |
Pension | Level 1, 2 and 3 | Real estate |  |  |
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Total Assets | 29.7 | 14.1 |
Pension | Level 1, 2 and 3 | Private debt |  |  |
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Total Assets | 22.2 | 25.7 |
Pension | Level 1, 2 and 3 | Other |  |  |
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Total Assets |  | 0.6 |
Pension | Level 1 |  |  |
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Total Assets | 144.3 | 156.8 |
Pension | Level 1 | Cash and cash equivalents |  |  |
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Total Assets | 3.3 | 0.0 |
Pension | Level 1 | U.S government and agency securities |  |  |
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Total Assets | 36.3 | 50.7 |
Pension | Level 1 | Corporate bonds |  |  |
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Total Assets |  | 0.0 |
Pension | Level 1 | Mutual fund - equities |  |  |
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Total Assets | 80.9 | 83.3 |
Pension | Level 1 | Mutual fund - fixed income |  |  |
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Total Assets | 12.5 | 12.2 |
Pension | Level 1 | Mutual fund - tactical tilt |  |  |
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Total Assets | 10.8 | 10.6 |
Pension | Level 1 | Equity securities |  |  |
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Total Assets | 0.5 |  |
Pension | Level 1 | Real estate |  |  |
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Total Assets | 0.0 | 0.0 |
Pension | Level 1 | Private debt |  |  |
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Total Assets | 0.0 | 0.0 |
Pension | Level 1 | Other |  |  |
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Total Assets |  | 0.0 |
Pension | Level 2 |  |  |
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Total Assets | 9.3 | 55.3 |
Pension | Level 2 | Cash and cash equivalents |  |  |
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Total Assets | 9.3 | 5.8 |
Pension | Level 2 | U.S government and agency securities |  |  |
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Total Assets | 0.0 | 9.1 |
Pension | Level 2 | Corporate bonds |  |  |
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Total Assets |  | 39.8 |
Pension | Level 2 | Equity securities |  |  |
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Total Assets | 0.0 |  |
Pension | Level 2 | Real estate |  |  |
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Total Assets | 0.0 | 0.0 |
Pension | Level 2 | Private debt |  |  |
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Total Assets | 0.0 | 0.0 |
Pension | Level 2 | Other |  |  |
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Total Assets |  | 0.6 |
Pension | Level 3 |  |  |
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Total Assets | 51.9 | 39.8 |
Pension | Level 3 | Cash and cash equivalents |  |  |
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Total Assets | 0.0 |  |
Pension | Level 3 | U.S government and agency securities |  |  |
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Total Assets | 0.0 |  |
Pension | Level 3 | Equity securities |  |  |
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Total Assets | 0.0 |  |
Pension | Level 3 | Real estate |  |  |
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Total Assets | 29.7 | 14.1 |
Pension | Level 3 | Private debt |  |  |
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Total Assets | 22.2 | 25.7 |
Pension | Assets measured at net asset value |  |  |
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Total Assets | $ 191.1 | $ 273.7 |
Redemption period | 90 days | 90 days |
Postretirement |  |  |
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Total Assets | $ 49.4 | $ 53.8 | $ 59.2
Postretirement | Level 1, 2 and 3 |  |  |
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Total Assets | 25.3 | 26.6 |
Postretirement | Level 1, 2 and 3 | Cash and cash equivalents |  |  |
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Total Assets | 3.6 | 2.2 |
Postretirement | Level 1, 2 and 3 | Mutual fund - equities |  |  |
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Total Assets | 11.9 | 13.5 |
Postretirement | Level 1, 2 and 3 | Mutual fund - fixed income |  |  |
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Total Assets | 6.6 | 7.3 |
Postretirement | Level 1, 2 and 3 | Mutual fund - tactical tilt |  |  |
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Total Assets | 2.3 | 2.5 |
Postretirement | Level 1, 2 and 3 | Real estate |  |  |
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Total Assets | 0.9 | 1.1 |
Postretirement | Level 1 |  |  |
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Total Assets | 25.3 | 26.6 |
Postretirement | Level 1 | Cash and cash equivalents |  |  |
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Total Assets | 3.6 | 2.2 |
Postretirement | Level 1 | Mutual fund - equities |  |  |
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Total Assets | 11.9 | 13.5 |
Postretirement | Level 1 | Mutual fund - fixed income |  |  |
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Total Assets | 6.6 | 7.3 |
Postretirement | Level 1 | Mutual fund - tactical tilt |  |  |
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Total Assets | 2.3 | 2.5 |
Postretirement | Level 1 | Real estate |  |  |
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Total Assets | 0.9 | 1.1 |
Postretirement | Assets measured at net asset value |  |  |
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Total Assets | $ 24.1 | $ 27.2 |

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