Segment Information (Details) - USD ($) $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2023		Jun. 30, 2022		Jun. 30, 2023		Jun. 30, 2022
Segment Reporting Information [Line Items]
Regulated Operating Revenue, Electric	$ 844		$ 884		$ 1,764		$ 1,712
Revenues Including Intersegment Revenues					1,764		1,712
Net income	93		132		307		308
Unregulated Operating Revenue	13		11		29		28
Regulated and Unregulated Operating Revenue	1,128		1,169		2,875		2,592
Affiliate Revenue	1		1		2		2
Total revenues
Segment Reporting Information [Line Items]
Regulated and Unregulated Operating Revenue			1,128		2,875
Regulated Electric
Segment Reporting Information [Line Items]
Revenues Including Intersegment Revenues	844		884
Net income	103		116		202		212
Regulated Natural Gas
Segment Reporting Information [Line Items]
Revenues Including Intersegment Revenues	271		274		1,082		852
Net income	(16)		14		97		95
All Other
Segment Reporting Information [Line Items]
Net income	6		2		8		1
All Other | Total revenues
Segment Reporting Information [Line Items]
Unregulated Operating Revenue	$ 13	[1]	$ 11	[1]	$ 29	[2]	$ 28	[2]

[1] Total revenues include $1 million of other affiliate revenue for the three months ended June 30, 2023 and 2022.

[2] Total revenues include $2 million of other affiliate revenue for the six months ended June 30, 2023 and 2022.