Qualifying Cash Flow Hedges (Details) - USD ($)		12 Months Ended
		Dec. 31, 2024	Dec. 31, 2023		Dec. 31, 2022
Impact of Derivative Activity
Fair Value Hedges, Net		$ 0	$ 0		$ 0
Not Designated as Hedging Instrument
Impact of Derivative Activity
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, before Tax		0	0		0
Derivative Instruments Gain (Loss) Reclassified To Regulatory Assets And Liabilities Net		48,000,000	(150,000,000)		(26,000,000)
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net		0	0		0
Pre-tax gains (losses) reclassified into income during the period from regulatory assets and (liabilities)		(22,000,000)	(138,000,000)		(13,000,000)
Derivative, Gain (Loss) on Derivative, Net		(49,000,000)	(34,000,000)		(2,000,000)
Not Designated as Hedging Instrument | Commodity Trading Contract
Impact of Derivative Activity
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net		0	0		0
Pre-tax gains (losses) reclassified into income during the period from regulatory assets and (liabilities)		0	0		0
Derivative, Gain (Loss) on Derivative, Net	[1]	(27,000,000)	(7,000,000)		25,000,000
Not Designated as Hedging Instrument | Electric Commodity Contract
Impact of Derivative Activity
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, before Tax		0	0		0
Derivative Instruments Gain (Loss) Reclassified To Regulatory Assets And Liabilities Net		44,000,000	(137,000,000)		(10,000,000)
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net		0	0		0
Pre-tax gains (losses) reclassified into income during the period from regulatory assets and (liabilities)	[2]	22,000,000	(123,000,000)		(3,000,000)
Derivative, Gain (Loss) on Derivative, Net		0	0		0
Not Designated as Hedging Instrument | Natural Gas Commodity Contract
Impact of Derivative Activity
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, before Tax		0	0		0
Derivative Instruments Gain (Loss) Reclassified To Regulatory Assets And Liabilities Net		4,000,000	(13,000,000)		(16,000,000)
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net		0	0		0
Pre-tax gains (losses) reclassified into income during the period from regulatory assets and (liabilities)		0	15,000,000	[3]	(10,000,000)	[3]
Derivative, Gain (Loss) on Derivative, Net	[3],[4]	(22,000,000)	(27,000,000)		(27,000,000)
Cash Flow Hedges | Designated as Hedging Instrument
Impact of Derivative Activity
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, before Tax		29,000,000	(2,000,000)		22,000,000
Derivative Instruments Gain (Loss) Reclassified To Regulatory Assets And Liabilities Net		0	0		0
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net		(3,000,000)	(5,000,000)		(7,000,000)
Pre-tax gains (losses) reclassified into income during the period from regulatory assets and (liabilities)		0	0		0
Derivative, Gain (Loss) on Derivative, Net		0	0		0
Cash Flow Hedges | Designated as Hedging Instrument | Interest Rate Contract
Impact of Derivative Activity
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, before Tax		29,000,000	(2,000,000)		22,000,000
Derivative Instruments Gain (Loss) Reclassified To Regulatory Assets And Liabilities Net		0	0		0
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	[5]	(3,000,000)	(5,000,000)		(7,000,000)
Pre-tax gains (losses) reclassified into income during the period from regulatory assets and (liabilities)		0	0		0
Derivative, Gain (Loss) on Derivative, Net		$ 0	$ 0		$ 0

[1] Recorded to electric revenues. Presented amounts do not reflect non-derivative transactions or margin sharing with customers.

[2] 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.

[3] Other than $3 million of 2024 losses recorded to electric fuel and purchased power, amounts are recorded to cost of natural gas sold and transported. Amounts are subject to cost-recovery mechanisms and reclassified out of income to a regulatory asset, as appropriate.

[4] Relates primarily to option premium amortization.

[5] Recorded to interest charges.