OPERATING REVENUES - OTHER OPERATING REVENUES (Details) - Utility - Other operating revenues - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Disaggregation of Operating Revenues
Other operating revenues	$ 5.4	$ 0.7	$ 2.3
Late payment charges
Disaggregation of Operating Revenues
Other operating revenues	3.9	2.0	3.2
Alternative revenues
Disaggregation of Operating Revenues
Other operating revenues	1.4	(1.4)	(1.1)
Rental revenues
Disaggregation of Operating Revenues
Other operating revenues	$ 0.1	$ 0.1	$ 0.2