Segment Information (Details) - USD ($) $ in Millions	3 Months Ended				9 Months Ended
	Sep. 30, 2023		Sep. 30, 2022		Sep. 30, 2023		Sep. 30, 2022
Segment Reporting Information [Line Items]
Net income	$ 260		$ 269		$ 526		$ 514
Natural gas	65		102		563		703
Other	13		12		35		33
Regulated and Unregulated Operating Revenue	1,591		1,844		4,556		5,044
Affiliate Revenue	130		132		368		394
Total revenues
Segment Reporting Information [Line Items]
Regulated and Unregulated Operating Revenue	1,592	[1],[2]	1,844	[1],[2]	4,558	[3],[4]	5,045	[3],[4]
Intersegment Eliminations
Segment Reporting Information [Line Items]
Regulated and Unregulated Operating Revenue	(1)		0		(2)		(1)
Regulated Electric
Segment Reporting Information [Line Items]
Net income	263		275		508		486
Revenues Including Intersegment Revenues	1,513	[1]	1,730	[1]	3,958	[3]	4,308	[3]
Regulated Natural Gas
Segment Reporting Information [Line Items]
Net income	(8)		(12)		13		21
Revenues Including Intersegment Revenues	66		102		565		704
Regulated Natural Gas | Total revenues
Segment Reporting Information [Line Items]
Natural gas	65	[2]	102	[2]	563	[4]	703	[4]
Regulated Natural Gas | Intersegment Eliminations
Segment Reporting Information [Line Items]
Natural gas	1		0		2		1
All Other
Segment Reporting Information [Line Items]
Net income	5		6		5		7
All Other | Total revenues
Segment Reporting Information [Line Items]
Other	$ 13		$ 12		$ 35		$ 33

[1] Operating revenues include $130 million and $132 million of affiliate electric revenue for the three months ended Sept. 30, 2023 and 2022.

[2] Operating revenues include an immaterial amount of affiliate gas revenue for the three months ended Sept. 30, 2023 and 2022.

[3] Operating revenues include $368 million and $394 million of affiliate electric revenue for the six months ended Sept. 30, 2023 and 2022.

[4] Operating revenues include an immaterial amount of affiliate gas revenue for the nine months ended Sept. 30, 2023 and 2022.