Revenues (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Retail
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	$ 976	$ 997	$ 2,519	$ 2,227
Retail | Residential
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	438	460	1,316	1,151
Retail | Commercial and Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	525	524	1,176	1,051
Retail | Other [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	13	13	27	25
Wholesale Distribution [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	42	71	117	137
Transmission Services [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	18	21	43	40
Other
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	45	45	100	100
Total revenue from contracts with customers
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	1,081	1,134	2,779	2,504
Alternative and Other [Member]
Disaggregation of Revenue [Line Items]
Alternative revenue and other	47	35	96	88
Regulated Electric | Retail
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	727	749	1,497	1,446
Regulated Electric | Retail | Residential
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	272	292	605	594
Regulated Electric | Retail | Commercial and Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	442	444	865	827
Regulated Electric | Retail | Other [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	13	13	27	25
Regulated Electric | Wholesale Distribution [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	42	71	117	137
Regulated Electric | Transmission Services [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	18	21	43	40
Regulated Electric | Other
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	17	12	28	24
Regulated Electric | Total revenue from contracts with customers
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	804	853	1,685	1,647
Regulated Electric | Alternative and Other [Member]
Disaggregation of Revenue [Line Items]
Alternative revenue and other	40	31	79	65
Regulated Natural Gas | Retail
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	236	237	993	765
Regulated Natural Gas | Retail | Residential
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	161	164	702	550
Regulated Natural Gas | Retail | Commercial and Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	75	73	291	215
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	28	33	72	76
Regulated Natural Gas | Total revenue from contracts with customers
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	264	270	1,065	841
Regulated Natural Gas | Alternative and Other [Member]
Disaggregation of Revenue [Line Items]
Alternative revenue and other	7	4	17	11
All Other | Retail
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	13	11	29	16
All Other | Retail | Residential
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	5	4	9	7
All Other | Retail | Commercial and Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	8	7	20	9
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	13	11	29	16
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	1,128	1,169	2,875	2,592
Total revenues | Regulated Electric
Disaggregation of Revenue [Line Items]
Total revenues	844	884	1,764	1,712
Total revenues | Regulated Natural Gas
Disaggregation of Revenue [Line Items]
Total revenues	271	274	1,082	852
Total revenues | All Other
Disaggregation of Revenue [Line Items]
Total revenues	$ 13	$ 11	$ 29	$ 28