Impact of Derivative Activities on Income and Accumulated Other Comprehensive Loss (Details) - Not Designated as Hedging Instrument - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Derivative [Line Items]
Derivative Instruments Gain (Loss) Reclassified To Regulatory Assets And Liabilities Net		$ (3)	$ 28	$ (7)
Pre-tax gains (losses) reclassified into income during the period from regulatory assets and (liabilities)		2	(20)
Electric Commodity Contract
Derivative [Line Items]
Derivative Instruments Gain (Loss) Reclassified To Regulatory Assets And Liabilities Net		(3)	28	$ (7)
Pre-tax gains (losses) reclassified into income during the period from regulatory assets and (liabilities)	[1]	$ (2)	$ 20

[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.