Income Taxes (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Taxes [Abstract]
Investment Tax Credit	$ 94	$ 67	$ 64
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate	21.00%	21.00%	21.00%
Tax Adjustments, Settlements, and Unusual Provisions	$ 166	$ 149	$ 139
Deferred Tax Assets, Valuation Allowance	(21)	(21)
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	11	8	$ 7
Operating Loss Carryforwards, Valuation Allowance	$ 19	$ 21

Income Taxes [Abstract]

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- Definition

Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized.

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- Definition

Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

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- Definition

The amount deducted from an entities' taxes, reflecting a percentage of an amount invested in certain assets spread over the useful life of those assets; includes deferred investment tax credits.

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The portion of the valuation allowance pertaining to the deferred tax asset representing potential future taxable deductions from net operating loss carryforwards for which it is more likely than not that a tax benefit will not be realized.

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Amount of increase (decrease) to previously recorded tax expense. Includes, but is not limited to, significant settlements of income tax disputes, and unusual tax positions or infrequent actions taken by the entity, including tax assessment reversal, and IRS tax settlement.

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The total amount of unrecognized tax benefits that, if recognized, would affect the effective tax rate.

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