FAIR VALUE MEASUREMENTS - FINANCIAL INSTRUMENTS (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Financial instruments
Preferred stock	$ 30.4	$ 30.4
Carrying amount
Financial instruments
Preferred stock	30.4	30.4
Long-term debt, including current portion	3,355.1	3,354.4
Fair value
Financial instruments
Preferred stock	20.3	21.4
Long-term debt, including current portion	$ 3,198.6	$ 3,255.4