OPERATING REVENUES - OTHER OPERATING REVENUES (Details) - Other operating revenues - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Disaggregation of Operating Revenues
Other operating revenues	$ 9.2	$ 13.4	$ 113.5	$ 63.3
Late payment charges
Disaggregation of Operating Revenues
Other operating revenues	10.4	12.4	39.1	45.8
Alternative revenues
Disaggregation of Operating Revenues
Other operating revenues	(1.7)	0.0	71.1	13.9
Other
Disaggregation of Operating Revenues
Other operating revenues	$ 0.5	$ 1.0	$ 3.3	$ 3.6