Annual report [Section 13 and 15(d), not S-K Item 405]

BENEFIT PLANS - Fair Value of Postretirement Assets (Details)

v3.25.4
BENEFIT PLANS - Fair Value of Postretirement Assets (Details) - USD ($)
$ in Millions
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets   $ 263.1  
U.S. Equity      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets   34.2  
International Equity      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets   14.3  
Fixed Income      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets   193.0  
Private Equity      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets   13.3  
Real Assets      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets   4.5  
Cash      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets   3.8  
Other Benefits      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets $ 9.8 10.7 $ 10.7
Other Benefits | Fair Value      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 9.8 10.7  
Fair Value, Inputs, Level 1, Level 2, and Level 3 | Other Benefits | Fair Value      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 7.6 8.5  
Fair Value, Inputs, Level 1, Level 2, and Level 3 | Other Benefits | U.S. Equity | Fair Value      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 1.2 1.1  
Fair Value, Inputs, Level 1, Level 2, and Level 3 | Other Benefits | International Equity | Fair Value      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 0.6 0.5  
Fair Value, Inputs, Level 1, Level 2, and Level 3 | Other Benefits | Fixed Income | Fair Value      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 5.0 6.2  
Fair Value, Inputs, Level 1, Level 2, and Level 3 | Other Benefits | Private Equity | Fair Value      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 0.4 0.4  
Fair Value, Inputs, Level 1, Level 2, and Level 3 | Other Benefits | Real Assets | Fair Value      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 0.1 0.2  
Fair Value, Inputs, Level 1, Level 2, and Level 3 | Other Benefits | Cash | Fair Value      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 0.3 0.1  
Quoted Prices in Active Markets for Identical Assets (Level 1)      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets   3.8  
Quoted Prices in Active Markets for Identical Assets (Level 1) | U.S. Equity      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets   0.0  
Quoted Prices in Active Markets for Identical Assets (Level 1) | International Equity      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets   0.0  
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fixed Income      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets   0.0  
Quoted Prices in Active Markets for Identical Assets (Level 1) | Private Equity      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets   0.0  
Quoted Prices in Active Markets for Identical Assets (Level 1) | Real Assets      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets   0.0  
Quoted Prices in Active Markets for Identical Assets (Level 1) | Cash      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets   3.8  
Quoted Prices in Active Markets for Identical Assets (Level 1) | Other Benefits | Fair Value      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 0.3 0.1  
Quoted Prices in Active Markets for Identical Assets (Level 1) | Other Benefits | U.S. Equity | Fair Value      
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) | Other Benefits | International Equity | Fair Value      
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) | Other Benefits | Fixed Income | Fair Value      
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) | Other Benefits | Private Equity | Fair Value      
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) | Other Benefits | Real Assets | Fair Value      
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) | Other Benefits | Cash | Fair Value      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 0.3 0.1  
Significant Other Observable Inputs (Level 2)      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets   241.5  
Significant Other Observable Inputs (Level 2) | U.S. Equity      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets   34.2  
Significant Other Observable Inputs (Level 2) | International Equity      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets   14.3  
Significant Other Observable Inputs (Level 2) | Fixed Income      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets   193.0  
Significant Other Observable Inputs (Level 2) | Private Equity      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets   0.0  
Significant Other Observable Inputs (Level 2) | Real Assets      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets   0.0  
Significant Other Observable Inputs (Level 2) | Cash      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets   0.0  
Significant Other Observable Inputs (Level 2) | Other Benefits | Fair Value      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 6.8 7.8  
Significant Other Observable Inputs (Level 2) | Other Benefits | U.S. Equity | Fair Value      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 1.2 1.1  
Significant Other Observable Inputs (Level 2) | Other Benefits | International Equity | Fair Value      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 0.6 0.5  
Significant Other Observable Inputs (Level 2) | Other Benefits | Fixed Income | Fair Value      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 5.0 6.2  
Significant Other Observable Inputs (Level 2) | Other Benefits | Private Equity | Fair Value      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 0.0 0.0  
Significant Other Observable Inputs (Level 2) | Other Benefits | Real Assets | Fair Value      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 0.0 0.0  
Significant Other Observable Inputs (Level 2) | Other Benefits | Cash | Fair Value      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 0.0 0.0  
Significant Unobservable Inputs (Level 3)      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets   17.8  
Significant Unobservable Inputs (Level 3) | U.S. Equity      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets   0.0  
Significant Unobservable Inputs (Level 3) | International Equity      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets   0.0  
Significant Unobservable Inputs (Level 3) | Fixed Income      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets   0.0  
Significant Unobservable Inputs (Level 3) | Private Equity      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 12.5 13.3 13.8
Significant Unobservable Inputs (Level 3) | Real Assets      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 3.4 4.5 $ 4.8
Significant Unobservable Inputs (Level 3) | Cash      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets   0.0  
Significant Unobservable Inputs (Level 3) | Other Benefits | Fair Value      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 0.5 0.6  
Significant Unobservable Inputs (Level 3) | Other Benefits | U.S. Equity | Fair Value      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 0.0 0.0  
Significant Unobservable Inputs (Level 3) | Other Benefits | International Equity | Fair Value      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 0.0 0.0  
Significant Unobservable Inputs (Level 3) | Other Benefits | Fixed Income | Fair Value      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 0.0 0.0  
Significant Unobservable Inputs (Level 3) | Other Benefits | Private Equity | Fair Value      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 0.4 0.4  
Significant Unobservable Inputs (Level 3) | Other Benefits | Real Assets | Fair Value      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 0.1 0.2  
Significant Unobservable Inputs (Level 3) | Other Benefits | Cash | Fair Value      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 0.0 0.0  
Investments measured at net asset value | Other Benefits | Fair Value      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets $ 2.2 $ 2.2