Operating Revenues - Other Non-Utility Operating Revenues (Details) - Revenues from contracts with customers - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Disaggregation of Operating Revenues
Revenues from contracts with customers	$ 8,785.3	$ 9,568.1	$ 8,235.7
Other non-utility revenues
Disaggregation of Operating Revenues
Revenues from contracts with customers	208.1	143.2	101.5
Other non-utility revenues | We Power revenues
Disaggregation of Operating Revenues
Revenues from contracts with customers	23.5	23.4	23.3
Other non-utility revenues | Other
Disaggregation of Operating Revenues
Revenues from contracts with customers	0.1	0.1	0.1
Transferred over time | Other non-utility revenues | Wind generation revenues
Disaggregation of Operating Revenues
Revenues from contracts with customers	164.9	101.0	60.3
Transferred over time | Other non-utility revenues | Appliance service repairs
Disaggregation of Operating Revenues
Revenues from contracts with customers	$ 19.6	$ 18.7	$ 17.8