Annual report pursuant to Section 13 and 15(d)

BENEFIT PLANS - Fair Value of Pension Assets (Details)

v3.24.0.1
BENEFIT PLANS - Fair Value of Pension Assets (Details) - USD ($)
$ in Millions
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Private Equity Commitments      
Defined Benefit Plan Disclosure [Line Items]      
Commitments related to investments $ 10.0 $ 12.2  
Real Asset Commitments      
Defined Benefit Plan Disclosure [Line Items]      
Commitments related to investments 0.2 0.2  
Pension Benefits      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 363.5 399.0 $ 600.5
U.S. Equity | Pension Benefits      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 40.9 33.9  
International Equity | Pension Benefits      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 35.6 30.8  
Fixed Income | Pension Benefits      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 243.3 313.5  
Private Equity | Pension Benefits      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 13.8 13.1  
Real Assets | Pension Benefits      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 4.8 4.8  
Cash | Pension Benefits      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 25.1 2.9  
Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension Benefits      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 25.1 36.8  
Quoted Prices in Active Markets for Identical Assets (Level 1) | U.S. Equity | Pension Benefits      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 0.0 33.9  
Quoted Prices in Active Markets for Identical Assets (Level 1) | International Equity | Pension Benefits      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 0.0 0.0  
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fixed Income | Pension Benefits      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 0.0 0.0  
Quoted Prices in Active Markets for Identical Assets (Level 1) | Private Equity | Pension Benefits      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 0.0 0.0  
Quoted Prices in Active Markets for Identical Assets (Level 1) | Real Assets | Pension Benefits      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 0.0 0.0  
Quoted Prices in Active Markets for Identical Assets (Level 1) | Cash | Pension Benefits      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 25.1 2.9  
Significant Other Observable Inputs (Level 2) | Pension Benefits      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 319.8 344.3  
Significant Other Observable Inputs (Level 2) | U.S. Equity | Pension Benefits      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 40.9 0.0  
Significant Other Observable Inputs (Level 2) | International Equity | Pension Benefits      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 35.6 30.8  
Significant Other Observable Inputs (Level 2) | Fixed Income | Pension Benefits      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 243.3 313.5  
Significant Other Observable Inputs (Level 2) | Private Equity | Pension Benefits      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 0.0 0.0  
Significant Other Observable Inputs (Level 2) | Real Assets | Pension Benefits      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 0.0 0.0  
Significant Other Observable Inputs (Level 2) | Cash | Pension Benefits      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 0.0 0.0  
Significant Unobservable Inputs (Level 3) | Pension Benefits      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 18.6 17.9  
Significant Unobservable Inputs (Level 3) | U.S. Equity | Pension Benefits      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 0.0 0.0  
Significant Unobservable Inputs (Level 3) | International Equity | Pension Benefits      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 0.0 0.0  
Significant Unobservable Inputs (Level 3) | Fixed Income | Pension Benefits      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 0.0 0.0  
Significant Unobservable Inputs (Level 3) | Private Equity | Pension Benefits      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 13.8 13.1  
Significant Unobservable Inputs (Level 3) | Real Assets | Pension Benefits      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 4.8 4.8  
Significant Unobservable Inputs (Level 3) | Cash | Pension Benefits      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets $ 0.0 $ 0.0