Revenues (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Retail
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	$ 4,965	$ 4,049	$ 3,547
Retail | Residential
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	2,559	2,002	1,735
Retail | C&I
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	2,354	1,998	1,764
Retail | Other
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	52	49	48
Wholesale
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	286	228	212
Transmission
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	88	75	62
Other
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	204	203	181
Total revenue from contracts with customers
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	5,543	4,555	4,002
Alternative revenue and other
Disaggregation of Revenue [Line Items]
Alternative revenue and other	165	260	181
Regulated Electric | Retail
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	3,236	2,883	2,633
Regulated Electric | Retail | Residential
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	1,341	1,174	1,073
Regulated Electric | Retail | C&I
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	1,843	1,660	1,512
Regulated Electric | Retail | Other
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	52	49	48
Regulated Electric | Wholesale
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	286	228	212
Regulated Electric | Transmission
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	88	75	62
Regulated Electric | Other
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	53	44	56
Regulated Electric | Total revenue from contracts with customers
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	3,663	3,230	2,963
Regulated Electric | Alternative revenue and other
Disaggregation of Revenue [Line Items]
Alternative revenue and other	132	183	153
Regulated Natural Gas | Retail
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	1,682	1,124	875
Regulated Natural Gas | Retail | Residential
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	1,203	816	650
Regulated Natural Gas | Retail | C&I
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	479	308	225
Regulated Natural Gas | Retail | Other
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	0	0	0
Regulated Natural Gas | Wholesale
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	0	0	0
Regulated Natural Gas | Transmission
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	0	0	0
Regulated Natural Gas | Other
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	151	159	125
Regulated Natural Gas | Total revenue from contracts with customers
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	1,833	1,283	1,000
Regulated Natural Gas | Alternative revenue and other
Disaggregation of Revenue [Line Items]
Alternative revenue and other	27	72	24
All Other | Retail
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	47	42	39
All Other | Retail | Residential
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	15	12	12
All Other | Retail | C&I
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	32	30	27
All Other | Retail | Other
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	0	0	0
All Other | Wholesale
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	0	0	0
All Other | Transmission
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	0	0	0
All Other | Other
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	0	0	0
All Other | Total revenue from contracts with customers
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	47	42	39
All Other | Alternative revenue and other
Disaggregation of Revenue [Line Items]
Alternative revenue and other	6	5	4
Total revenues
Disaggregation of Revenue [Line Items]
Total revenues	5,708	4,815	4,183
Total revenues | Regulated Electric
Disaggregation of Revenue [Line Items]
Total revenues	3,795	3,413	3,116
Total revenues | Regulated Natural Gas
Disaggregation of Revenue [Line Items]
Total revenues	1,860	1,355	1,024
Total revenues | All Other
Disaggregation of Revenue [Line Items]
Total revenues	$ 53	$ 47	$ 43