Segment Information (Details) - USD ($) $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2024		Jun. 30, 2023		Jun. 30, 2024		Jun. 30, 2023
Segment Reporting Information [Line Items]
Net income	$ 23		$ 26		$ 66		$ 71
Regulated and Unregulated Operating Revenue	267		260		577	[1]	591	[1]
Natural gas	21		24		75		101
Total revenues
Segment Reporting Information [Line Items]
Regulated and Unregulated Operating Revenue	267	[2]	260	[2]	577		592
Intersegment Eliminations
Segment Reporting Information [Line Items]
Regulated and Unregulated Operating Revenue					0		(1)
Regulated Electric
Segment Reporting Information [Line Items]
Net income	23		30		56		63
Regulated Electric | Total revenues
Segment Reporting Information [Line Items]
Regulated Operating Revenue, Electric	246	[2]	236	[2]	502	[1]	490	[1]
Regulated Natural Gas
Segment Reporting Information [Line Items]
Net income	(2)		(3)		8		8
Revenues Including Intersegment Revenues	21		24		75		102
Regulated Natural Gas | Total revenues
Segment Reporting Information [Line Items]
Natural gas					75		101
Regulated Natural Gas | Intersegment Eliminations
Segment Reporting Information [Line Items]
Natural gas					0		1
All Other
Segment Reporting Information [Line Items]
Net income	$ 2		$ (1)		$ 2		$ 0

[1] Total revenues include $107 million and $101 million of affiliate electric revenue for the six months ended June 30, 2024 and 2023, respectively.

[2] Total revenues include $54 million and $51 million of affiliate electric revenue for the three months ended June 30, 2024 and 2023, respectively.