OPERATING REVENUES - OTHER NON-UTILITY OPERATING REVENUES (Details) - Revenues from contracts with customers - 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
Revenues from contracts with customers	$ 1,854.3	$ 1,944.0	$ 6,202.2	$ 6,612.2
Other non-utility revenues
Disaggregation of Operating Revenues
Revenues from contracts with customers	51.2	48.8	167.0	150.1
Other non-utility revenues | We Power revenues
Disaggregation of Operating Revenues
Revenues from contracts with customers	6.1	5.7	18.2	17.5
Transferred over time | Other non-utility revenues | Wind generation revenues
Disaggregation of Operating Revenues
Revenues from contracts with customers	40.0	38.2	133.8	117.8
Transferred over time | Other non-utility revenues | Appliance service revenues
Disaggregation of Operating Revenues
Revenues from contracts with customers	$ 5.1	$ 4.9	$ 15.0	$ 14.8