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v3.23.3

Property, Plant and Equipment (Details) - USD ($) $ in Millions | 9 Months Ended |
--- | --- | ---
Sep. 30, 2023 | Dec. 31, 2022
Asset Retirement Obligations (ARO) |  |  |
Beginning Balance | [1],[2],[3],[4],[5],[6] | $ 2,944.9 |
Accretion Expense | [1],[2],[3],[4],[5],[6] | 86.0 |
Liabilities Incurred | [1],[2],[3],[4],[5],[6] | 12.9 |
Liabilities Settled | [1],[2],[3],[4],[5],[6] | (98.1) |
Asset Retirement Obligation, Revision of Estimate | [1],[2],[3],[4],[5],[6] | 13.8 |
Ending Balance | [1],[2],[3],[4],[5],[6] | 2,959.5 |
Competitive Contracted Renewable Portfolio |  |  |
Asset Retirement Obligations (ARO) |  |  |
Liabilities Settled |  | (31.0) |
Southwestern Electric Power Co [Member] |  |  |
Asset Retirement Obligations (ARO) |  |  |
Beginning Balance | [1],[3],[4],[5] | 282.2 |
Accretion Expense | [1],[3],[4],[5] | 10.0 |
Liabilities Incurred | [1],[3],[4],[5] | 7.1 |
Liabilities Settled | [1],[3],[4],[5] | (37.9) |
Asset Retirement Obligation, Revision of Estimate | [1],[3],[4],[5] | 0.4 |
Ending Balance | [1],[3],[4],[5] | 261.8 |
Pirkey Power Plant and Dolet Hills Power Station | Southwestern Electric Power Co [Member] |  |  |
Asset Retirement Obligations (ARO) |  |  |
Liabilities Settled |  | (35.0) |
Cook plant | Indiana Michigan Power Co [Member] |  |  |
Property, Plant and Equipment (Textuals) |  |  |
Asset Retirement Obligations (ARO) Liability for Nuclear Decommissioning of the Cook Plant |  | $ 2,050.0 | $ 2,000.0
[1] | In 2023, SWEPCo settled $35 million of costs related to closure/reclamation work performed due to the recent retirements of the Pirkey Plant and Dolet Hills Power Station. See “Coal-Fired Generation Plants” section of Note 4 for additional information.
[2] | In August 2023, AEP completed the sale of its competitive contracted renewables portfolio to a nonaffiliated party and settled ARO liabilities of $31 million. See “Disposition of the Competitive Contracted Renewables Portfolio” section of Note 6 for additional information
[3] | Includes ARO related to Sabine and DHLC.
[4] | Includes ARO related to asbestos removal.
[5] | Includes ARO related to ash disposal facilities.
[6] | Includes ARO related to nuclear decommissioning costs for the Cook Plant of $2.05 billion and $2 billion as of September 30, 2023 and December 31, 2022, respectively.

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- Definition 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/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 -Topic 410 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org//1943274/2147481850/410-20-50-1 + Details
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- Definition 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 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 410 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (c)(3) -Publisher FASB -URI https://asc.fasb.org//1943274/2147481850/410-20-50-1 + Details
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- Definition 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 -Topic 410 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (c)(2) -Publisher FASB -URI https://asc.fasb.org//1943274/2147481850/410-20-50-1 + Details
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