Revenues (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024		Sep. 30, 2023
One Commercial and Industrial Customer | Revenue Benchmark | Customer Concentration Risk
Disaggregation of Revenue [Line Items]
Concentration Risk, Percentage			10.10%
Regulated Electric
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 584	$ 670	$ 1,419		$ 1,656
Regulated Electric | Total revenues
Disaggregation of Revenue [Line Items]
Total revenues	594	677	1,480		1,681
Regulated Electric | Retail
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	474	501	1,101		1,243
Regulated Electric | Retail | Residential
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	152	164	321		356
Regulated Electric | Retail | C&I
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	308	319	744	[1]	843
Regulated Electric | Retail | Other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	14	18	36		44
Regulated Electric | Wholesale
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	29	88	95		184
Regulated Electric | Transmission
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	80	81	221		227
Regulated Electric | Alternative and Other
Disaggregation of Revenue [Line Items]
Alternative revenue and other	10	7	61		25
Regulated Electric | Other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 1	$ 0	$ 2		$ 2

[1] For the nine months ended Sept. 30, 2024, revenues from one C&I customer represented approximately 10.1% of total revenues.