Fair Value of Financial Assets and Liabilities - Commodity Derivatives (Details) MWh in Millions, $ in Millions |
3 Months Ended | 6 Months Ended | |||||||
|---|---|---|---|---|---|---|---|---|---|
|
Jun. 30, 2026
USD ($)
MWh
|
Jun. 30, 2025
USD ($)
|
Jun. 30, 2026
USD ($)
MWh
|
Jun. 30, 2025
USD ($)
|
Dec. 31, 2025
MWh
|
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| Other Derivative Instruments | |||||||||
| Derivative [Line Items] | |||||||||
| Pre-tax gains (losses) reclassified into income during the period from regulatory assets and (liabilities) | $ 18 | $ (19) | $ 21 | $ (29) | |||||
| Electric Commodity [Member] | |||||||||
| Derivative [Line Items] | |||||||||
| Mwh of electricity | MWh | [1] | 15 | 15 | 7 | |||||
| cash flow hedge commodity | |||||||||
| Derivative [Line Items] | |||||||||
| Commodity contracts designated as cash flow hedges | $ 0 | $ 0 | |||||||
| Electric Commodity | Other Derivative Instruments | |||||||||
| Derivative [Line Items] | |||||||||
| Pre-tax gains (losses) reclassified into income during the period from regulatory assets and (liabilities) | [2] | $ 18 | $ (19) | $ 21 | $ (29) | ||||
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