Revenues (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Retail
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	$ 1,093	$ 1,211	$ 3,612	$ 3,438
Retail | Residential
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	491	571	1,807	1,722
Retail | Commercial and Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	589	627	1,765	1,678
Retail | Other [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	13	13	40	38
Wholesale Distribution [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	53	63	170	200
Transmission Services [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	25	25	68	65
Other
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	43	45	143	145
Total revenue from contracts with customers
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	1,214	1,344	3,993	3,848
Alternative and Other [Member]
Disaggregation of Revenue [Line Items]
Alternative revenue and other	76	39	172	127
Regulated Electric | Retail
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	949	1,000	2,446	2,446
Regulated Electric | Retail | Residential
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	398	431	1,003	1,025
Regulated Electric | Retail | Commercial and Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	538	556	1,403	1,383
Regulated Electric | Retail | Other [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	13	13	40	38
Regulated Electric | Wholesale Distribution [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	53	63	170	200
Regulated Electric | Transmission Services [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	25	25	68	65
Regulated Electric | Other
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	16	15	44	39
Regulated Electric | Total revenue from contracts with customers
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	1,043	1,103	2,728	2,750
Regulated Electric | Alternative and Other [Member]
Disaggregation of Revenue [Line Items]
Alternative revenue and other	70	34	149	99
Regulated Natural Gas | Retail
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	132	200	1,125	965
Regulated Natural Gas | Retail | Residential
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	88	136	790	686
Regulated Natural Gas | Retail | Commercial and Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	44	64	335	279
Regulated Natural Gas | Retail | Other [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	0	0	0	0
Regulated Natural Gas | Wholesale Distribution [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	0	0	0	0
Regulated Natural Gas | Transmission Services [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	0	0	0	0
Regulated Natural Gas | Other
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	27	30	99	106
Regulated Natural Gas | Total revenue from contracts with customers
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	159	230	1,224	1,071
Regulated Natural Gas | Alternative and Other [Member]
Disaggregation of Revenue [Line Items]
Alternative revenue and other	6	5	23	16
All Other | Retail
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	12	11	41	27
All Other | Retail | Residential
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	5	4	14	11
All Other | Retail | Commercial and Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	7	7	27	16
All Other | Retail | Other [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	0	0	0	0
All Other | Wholesale Distribution [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	0	0	0	0
All Other | Transmission Services [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	0	0	0	0
All Other | Other
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	0	0	0	0
All Other | Total revenue from contracts with customers
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	12	11	41	27
All Other | Alternative and Other [Member]
Disaggregation of Revenue [Line Items]
Alternative revenue and other	0	0	0	12
Total revenues
Disaggregation of Revenue [Line Items]
Total revenues	1,290	1,383	4,165	3,975
Total revenues | Regulated Electric
Disaggregation of Revenue [Line Items]
Total revenues	1,113	1,137	2,877	2,849
Total revenues | Regulated Natural Gas
Disaggregation of Revenue [Line Items]
Total revenues	165	235	1,247	1,087
Total revenues | All Other
Disaggregation of Revenue [Line Items]
Total revenues	$ 12	$ 11	$ 41	$ 39