Revenues (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025		Sep. 30, 2024
C&I | Customer Concentration Risk | Revenue from Contract with Customer Benchmark
Disaggregation of Revenue [Line Items]
Concentration Risk, Percentage			9.30%		10.10%
Regulated Electric
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 645	$ 584	$ 1,658		$ 1,419
Regulated Electric | Total revenues
Disaggregation of Revenue [Line Items]
Total revenues	655	594	1,684		1,480
Regulated Electric | Retail
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	528	474	1,337		1,101
Regulated Electric | Retail | Residential
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	153	152	362		321
Regulated Electric | Retail | C&I
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	359	308	936	[1]	744	[1]
Regulated Electric | Retail | Other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	16	14	39		36
Regulated Electric | Wholesale
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	33	29	81		95
Regulated Electric | Transmission
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	84	80	238		221
Regulated Electric | Alternative and Other
Disaggregation of Revenue [Line Items]
Alternative revenue and other	10	10	26		61
Regulated Electric | Other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 0	$ 1	$ 2		$ 2

[1] For the nine months ended Sept. 30, 2025 and 2024, revenues from one C&I customer represented approximately 9.3% and 10.1% of total revenues, respectively.