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Pension and Other Post-retirement Benefits - Fair Value Measurement of Plan Assets (Details) - USD ($)
$ in Millions
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Defined Benefit Plan Disclosure [Line Items]      
Total fair value of plan asset investments $ 18.5 $ 20.2  
Non-investment plan assets 0.1 0.1  
Total plan assets 18.6 20.3  
Short-term investments      
Defined Benefit Plan Disclosure [Line Items]      
Total fair value of plan asset investments 0.2 0.2  
Common stocks      
Defined Benefit Plan Disclosure [Line Items]      
Total fair value of plan asset investments 2.3 2.5  
U.S. Treasury securities      
Defined Benefit Plan Disclosure [Line Items]      
Total fair value of plan asset investments 6.5 6.7  
Other fixed income securities      
Defined Benefit Plan Disclosure [Line Items]      
Total fair value of plan asset investments 7.4 7.4  
Mutual funds      
Defined Benefit Plan Disclosure [Line Items]      
Total fair value of plan asset investments 1.2 1.0  
Private equity      
Defined Benefit Plan Disclosure [Line Items]      
Total fair value of plan asset investments 0.9 2.4  
Quoted Prices in Active Markets for Identical Contracts (Level 1)      
Defined Benefit Plan Disclosure [Line Items]      
Total fair value of plan asset investments 3.3 3.3  
Quoted Prices in Active Markets for Identical Contracts (Level 1) | Short-term investments      
Defined Benefit Plan Disclosure [Line Items]      
Total fair value of plan asset investments 0.2 0.2  
Quoted Prices in Active Markets for Identical Contracts (Level 1) | Common stocks      
Defined Benefit Plan Disclosure [Line Items]      
Total fair value of plan asset investments 2.3 2.5  
Quoted Prices in Active Markets for Identical Contracts (Level 1) | U.S. Treasury securities      
Defined Benefit Plan Disclosure [Line Items]      
Total fair value of plan asset investments 0.8 0.6  
Quoted Prices in Active Markets for Identical Contracts (Level 1) | Other fixed income securities      
Defined Benefit Plan Disclosure [Line Items]      
Total fair value of plan asset investments 0.0 0.0  
Quoted Prices in Active Markets for Identical Contracts (Level 1) | Mutual funds      
Defined Benefit Plan Disclosure [Line Items]      
Total fair value of plan asset investments 0.0 0.0  
Quoted Prices in Active Markets for Identical Contracts (Level 1) | Private equity      
Defined Benefit Plan Disclosure [Line Items]      
Total fair value of plan asset investments 0.0 0.0  
Significant Other Observable Inputs (Level 2)      
Defined Benefit Plan Disclosure [Line Items]      
Total fair value of plan asset investments 14.3 14.5  
Significant Other Observable Inputs (Level 2) | Short-term investments      
Defined Benefit Plan Disclosure [Line Items]      
Total fair value of plan asset investments 0.0 0.0  
Significant Other Observable Inputs (Level 2) | Common stocks      
Defined Benefit Plan Disclosure [Line Items]      
Total fair value of plan asset investments 0.0 0.0  
Significant Other Observable Inputs (Level 2) | U.S. Treasury securities      
Defined Benefit Plan Disclosure [Line Items]      
Total fair value of plan asset investments 5.7 6.1  
Significant Other Observable Inputs (Level 2) | Other fixed income securities      
Defined Benefit Plan Disclosure [Line Items]      
Total fair value of plan asset investments 7.4 7.4  
Significant Other Observable Inputs (Level 2) | Mutual funds      
Defined Benefit Plan Disclosure [Line Items]      
Total fair value of plan asset investments 1.2 1.0  
Significant Other Observable Inputs (Level 2) | Private equity      
Defined Benefit Plan Disclosure [Line Items]      
Total fair value of plan asset investments 0.0 0.0  
Significant Non- observable Inputs (Level 3)      
Defined Benefit Plan Disclosure [Line Items]      
Total fair value of plan asset investments 0.9 2.4  
Significant Non- observable Inputs (Level 3) | Short-term investments      
Defined Benefit Plan Disclosure [Line Items]      
Total fair value of plan asset investments 0.0 0.0  
Significant Non- observable Inputs (Level 3) | Common stocks      
Defined Benefit Plan Disclosure [Line Items]      
Total fair value of plan asset investments 0.0 0.0  
Significant Non- observable Inputs (Level 3) | U.S. Treasury securities      
Defined Benefit Plan Disclosure [Line Items]      
Total fair value of plan asset investments 0.0 0.0  
Significant Non- observable Inputs (Level 3) | Other fixed income securities      
Defined Benefit Plan Disclosure [Line Items]      
Total fair value of plan asset investments 0.0 0.0  
Significant Non- observable Inputs (Level 3) | Mutual funds      
Defined Benefit Plan Disclosure [Line Items]      
Total fair value of plan asset investments 0.0 0.0  
Significant Non- observable Inputs (Level 3) | Private equity      
Defined Benefit Plan Disclosure [Line Items]      
Total fair value of plan asset investments $ 0.9 $ 2.4 $ 2.2