FAIR VALUE MEASUREMENTS - FINANCIAL INSTRUMENTS (Details) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Financial instruments
Preferred stock of subsidiary	$ 30.4	$ 30.4
Carrying amount
Financial instruments
Preferred stock of subsidiary	30.4	30.4
Long-term debt, including current portion	16,517.2	15,464.2
Finance lease obligations	152.2	183.2
Fair value
Financial instruments
Preferred stock of subsidiary	21.5	22.7
Long-term debt, including current portion	$ 14,645.0	$ 13,921.3