PROPERTY, PLANT AND EQUIPMENT - Maturities of Lease Liabilities (Details) $ in Millions	Dec. 31, 2020 USD ($)
Operating Leases
2021	$ 36.5
2022	27.7
2023	22.9
2024	18.8
2025	13.7
Thereafter	52.7
Total undiscounted cash flows	172.3
Short-term lease liability	16.3
Long-term lease liability	86.6
Total lease liability	102.9
Difference between undiscounted cash flows and discounted cash flows	69.4
Finance Leases
2021	0.5
2022	0.3
2023	0.0
2024	0.0
2025	0.0
Thereafter	0.0
Total undiscounted cash flows	0.8
Short-term lease liability	0.3
Long-term lease liability	0.3
Total lease liability	0.6
Difference between undiscounted cash flows and discounted cash flows	$ 0.2