Revenues (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Total revenue from contracts with customers
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	$ 1,117	$ 1,162	$ 1,185
Retail
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	886	950	975
Retail | Residential
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	356	383	396
Retail | C&I
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	522	559	572
Retail | Other
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	8	8	7
Interchange
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	231	212	210
Alternative and Other [Member]
Disaggregation of Revenue [Line Items]
Alternative revenue and other	14	15	16
Regulated Electric | Total revenue from contracts with customers
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	983	1,007	991
Regulated Electric | Retail
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	758	800	785
Regulated Electric | Retail | Residential
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	283	299	293
Regulated Electric | Retail | C&I
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	468	494	485
Regulated Electric | Retail | Other
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	7	7	7
Regulated Electric | Interchange
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	225	207	206
Regulated Electric | Alternative and Other [Member]
Disaggregation of Revenue [Line Items]
Alternative revenue and other	12	12	11
Regulated Natural Gas | Total revenue from contracts with customers
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	133	154	194
Regulated Natural Gas | Retail
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	127	149	190
Regulated Natural Gas | Retail | Residential
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	73	84	103
Regulated Natural Gas | Retail | C&I
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	54	65	87
Regulated Natural Gas | Retail | Other
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0
Regulated Natural Gas | Interchange
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	6	5	4
Regulated Natural Gas | Alternative and Other [Member]
Disaggregation of Revenue [Line Items]
Alternative revenue and other	2	3	4
All Other | Total revenue from contracts with customers
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	1	1	0
All Other | Retail
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	1	1	0
All Other | Retail | Residential
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0
All Other | Retail | C&I
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0
All Other | Retail | Other
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	1	1	0
All Other | Interchange
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0
All Other | Alternative and Other [Member]
Disaggregation of Revenue [Line Items]
Alternative revenue and other	0	0	1
Total revenues
Disaggregation of Revenue [Line Items]
Total revenues	1,131	1,177	1,201
Total revenues | Regulated Electric
Disaggregation of Revenue [Line Items]
Total revenues	995	1,019	1,002
Total revenues | Regulated Natural Gas
Disaggregation of Revenue [Line Items]
Total revenues	135	157	198
Total revenues | All Other
Disaggregation of Revenue [Line Items]
Total revenues	$ 1	$ 1	$ 1