PENSION, HEALTH CARE AND OTHER POSTRETIREMENT BENEFITS - Summary of the Fair Value of the Defined Benefit Pension Plan Assets (Details) - Defined Benefit Pension - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Defined Benefit Plan Disclosure [Line Items]
Total investments in fair value hierarchy	$ 389.1	$ 354.7	$ 356.5
Total investments	416.8	380.0	381.8
NAV
Defined Benefit Plan Disclosure [Line Items]
Investments measured at NAV or its equivalent	27.7	25.3	25.3
Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Total investments in fair value hierarchy	150.6	132.1	109.7
Significant  Other Observable  Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Total investments in fair value hierarchy	238.5	222.6	246.8
Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Total investments in fair value hierarchy	7.6	8.7
Cash and cash equivalents | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Total investments in fair value hierarchy	7.6	8.7
Cash and cash equivalents | Significant  Other Observable  Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Total investments in fair value hierarchy	0.0	0.0
Equity investments
Defined Benefit Plan Disclosure [Line Items]
Total investments in fair value hierarchy	104.3	95.3	133.0
Equity investments | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Total investments in fair value hierarchy	99.4	86.6	72.9
Equity investments | Significant  Other Observable  Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Total investments in fair value hierarchy	4.9	8.7	60.1
Fixed income investments
Defined Benefit Plan Disclosure [Line Items]
Total investments in fair value hierarchy	248.9	226.5	188.9
Fixed income investments | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Total investments in fair value hierarchy	43.6	36.8	36.8
Fixed income investments | Significant  Other Observable  Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Total investments in fair value hierarchy	205.3	189.7	152.1
Other assets
Defined Benefit Plan Disclosure [Line Items]
Total investments in fair value hierarchy	28.3	24.2	34.6
Other assets | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Total investments in fair value hierarchy	0.0	0.0	0.0
Other assets | Significant  Other Observable  Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Total investments in fair value hierarchy	$ 28.3	$ 24.2	$ 34.6