Fair Value Measurements, Including Derivatives (Schedule of Assets and Liabilities Measured at Fair Value on Recurring Basis and Included in Level 3) (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2023	Mar. 31, 2022
Regulatory Assets
Beginning balance	$ 251	$ 148
Included in earnings:
Purchased power	1	3
Settlements	(1)	(3)
Transfers out of Level 3	0	0
Ending balance	188	225
Other Regulatory Assets Liabilities
Included in earnings:
Included in regulatory assets/liabilities	$ (63)	$ 77

Costs of power used for operations in prior periods that were expected to be recovered from customers in future periods.

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Amount of transfers of financial instrument classified as derivative asset (liability) after deduction of derivative liability (asset) out of level 3 of the fair value hierarchy.

+ References

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-Publisher FASB
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Fair value of financial instrument classified as derivative asset (liability) after deduction of derivative liability (asset), measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Amount of gain (loss) included in earnings for investments classified as other.

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Amount of gain (loss) recognized in settlement of litigation and insurance claims. Excludes claims within an insurance entity's normal claims settlement process.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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