Asset Retirement Obligations - Schedule of Asset Retirement Obligations (Details) - USD ($) $ in Millions	9 Months Ended
Sep. 30, 2025	Sep. 30, 2024	Dec. 31, 2024
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Liability at beginning of period	$ 4,078	$ 2,538
Accretion	144	126
Adjustment for change in estimates	(15)	18
Adjustment for obligations assumed through acquisition	0	1,368
Payments	(61)	(64)
Liability at end of period	4,146	3,986
Additions:
Accretion	144	126
Adjustment for change in estimates	(15)	18
Adjustment for obligations assumed through acquisition	0	1,368
Reductions:
Payments	(61)	(64)
Less amounts due currently	(202)	(102)	$ (142)
Noncurrent liability at end of period	3,944	3,884	$ 3,936
Asset retirement obligation, non-cash additions, asset retirement costs	(14)	7
Nuclear Plant Decommissioning
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Liability at beginning of period	3,240	1,742
Accretion	114	95
Adjustment for change in estimates	11	0
Adjustment for obligations assumed through acquisition	0	1,368
Payments	0	0
Liability at end of period	3,365	3,205
Additions:
Accretion	114	95
Adjustment for change in estimates	11	0
Adjustment for obligations assumed through acquisition	0	1,368
Reductions:
Payments	0	0
Less amounts due currently	0	0
Noncurrent liability at end of period	3,365	3,205
Increase (decrease) in regulatory liabilities	44	42
Nuclear Plant Decommissioning \| Operating Expense
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Accretion	70	53
Additions:
Accretion	70	53
Land Reclamation, Coal Ash, and Other
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Liability at beginning of period	838	796
Accretion	30	31
Adjustment for change in estimates	(26)	18
Adjustment for obligations assumed through acquisition	0	0
Payments	(61)	(64)
Liability at end of period	781	781
Additions:
Accretion	30	31
Adjustment for change in estimates	(26)	18
Adjustment for obligations assumed through acquisition	0	0
Reductions:
Payments	(61)	(64)
Less amounts due currently	(202)	(102)
Noncurrent liability at end of period	$ 579	$ 679

The carrying amount of a liability for an asset retirement obligation. An asset retirement obligation is a legal obligation associated with the disposal or retirement of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 410
-SubTopic 20
-Name Accounting Standards Codification
-Section 25
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481999/410-20-25-4

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
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-Publisher FASB
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Amount of accretion expense recognized during the period that is associated with an asset retirement obligation. Accretion expense measures and incorporates changes due to the passage of time into the carrying amount of the liability.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 410
-SubTopic 20
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481879/410-20-45-1

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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
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Current portion of the carrying amount of a liability for an asset retirement obligation. An asset retirement obligation is a legal obligation associated with the disposal or retirement of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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-Section 50
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Amount of asset retirement obligations settled, or otherwise disposed of, during the period. This may include asset retirement obligations transferred to third parties associated with the sale of a long-lived asset.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Noncurrent portion of the carrying amount of a liability for an asset retirement obligation. An asset retirement obligation is a legal obligation associated with the disposal or retirement of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees.

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The increase (decrease) during the reporting period in regulated liabilities. Regulated liabilities are created when regulatory agency permits an entity to defer revenues to the balance sheet.

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Asset Retirement Obligation Additions: [Abstract]

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Asset Retirement Obligation, Adjustment For New Cost Estimate

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Asset Retirement Obligation, Non-cash Additions, Asset Retirement Costs

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Asset Retirement Obligation, Obligation Assumed In Merger

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Asset Retirement Obligation Reductions: [Abstract]

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