Impact of Derivative Activities on Income and Accumulated Other Comprehensive Loss (Details) - USD ($)		12 Months Ended
		Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Derivative [Line Items]
Fair Value Hedges, Net		$ 0	$ 0	$ 0
Not Designated as Hedging Instrument
Derivative [Line Items]
Derivative Instruments Gain (Loss) Reclassified To Regulatory Assets And Liabilities Net		15,000,000	62,000,000	(88,000,000)
Pre-tax gains (losses) reclassified into income during the period from regulatory assets and (liabilities)		(26,000,000)	(43,000,000)	78,000,000
Electric Commodity Contract | Not Designated as Hedging Instrument
Derivative [Line Items]
Derivative Instruments Gain (Loss) Reclassified To Regulatory Assets And Liabilities Net		15,000,000	62,000,000	(88,000,000)
Pre-tax gains (losses) reclassified into income during the period from regulatory assets and (liabilities)	[1]	$ (26,000,000)	$ (43,000,000)	$ 78,000,000

[1] Recorded to electric fuel and purchased power. These derivative settlement gains and losses are shared with electric customers through fuel and purchased energy cost-recovery mechanisms and reclassified out of income as regulatory assets or liabilities, as appropriate. FTR settlements are shared with customers and do not have a material impact on net income. Presented amounts reflect changes in fair value between auction and settlement dates, but exclude the original auction fair value.