XML 204 R133.htm IDEA: XBRL DOCUMENT
v3.25.0.1

EFFECTS OF REGULATION - Regulatory Asset - I&M (Details) - USD ($) $ in Millions | 12 Months Ended |
--- | --- | ---
Dec. 31, 2023 | Dec. 31, 2024
Regulatory Asset [Line Items] |  |
Total Current Regulatory Assets | $ 514.0 | $ 445.9
Total Noncurrent Regulatory Assets | 5,092.4 | 5,129.2
Pending final regulatory approval |  |
Regulatory Asset [Line Items] |  |
Total Noncurrent Regulatory Assets | 837.3 | 1,310.8
Approved for recovery |  |
Regulatory Asset [Line Items] |  |
Total Noncurrent Regulatory Assets | 4,255.1 | 3,818.4
Earns/earning a return | Under-recovered Fuel Costs |  |
Regulatory Asset [Line Items] |  |
Total Current Regulatory Assets | 357.4 | $ 245.7
Remaining Recovery Period |  | 1 year
Earns/earning a return | Pending final regulatory approval |  |
Regulatory Asset [Line Items] |  |
Total Noncurrent Regulatory Assets | 349.9 | $ 395.1
Earns/earning a return | Pending final regulatory approval | Other Regulatory Assets Pending Final Regulatory Approval |  |
Regulatory Asset [Line Items] |  |
Total Noncurrent Regulatory Assets | 49.8 | 20.7
Earns/earning a return | Pending final regulatory approval | Storm-Related Costs |  |
Regulatory Asset [Line Items] |  |
Total Noncurrent Regulatory Assets | 0.0 | 51.0
Earns/earning a return | Approved for recovery |  |
Regulatory Asset [Line Items] |  |
Total Noncurrent Regulatory Assets | 1,946.9 | $ 1,711.5
Earns/earning a return | Approved for recovery | Plant Retirement Costs - Asset Retirement Obligation Costs |  |
Regulatory Asset [Line Items] |  |
Remaining Recovery Period |  | 16 years
Total Noncurrent Regulatory Assets | 110.8 | $ 111.0
Earns/earning a return | Approved for recovery | Storm-Related Costs |  |
Regulatory Asset [Line Items] |  |
Remaining Recovery Period |  | 7 years
Total Noncurrent Regulatory Assets | 170.9 | $ 106.7
Earns/earning a return | Approved for recovery | Plant Retirement Costs - Unrecovered Plant |  |
Regulatory Asset [Line Items] |  |
Remaining Recovery Period |  | 22 years
Total Noncurrent Regulatory Assets | 664.2 | $ 661.2
Earns/earning a return | Approved for recovery | Rockport Plant Dry Sorbent Injection System and Selective Catalytic Reduction |  |
Regulatory Asset [Line Items] |  |
Remaining Recovery Period |  | 4 years
Total Noncurrent Regulatory Assets | 46.9 | $ 37.3
Earns/earning a return | Approved for recovery | Other Regulatory Assets Approved for Recovery |  |
Regulatory Asset [Line Items] |  |
Total Noncurrent Regulatory Assets | 124.9 | 159.9
Does not earns/earning a return | Under-recovered Fuel Costs |  |
Regulatory Asset [Line Items] |  |
Total Current Regulatory Assets | 62.7 | $ 116.0
Remaining Recovery Period |  | 1 year
Does not earns/earning a return | Pending final regulatory approval |  |
Regulatory Asset [Line Items] |  |
Total Noncurrent Regulatory Assets | 487.4 | $ 915.7
Does not earns/earning a return | Pending final regulatory approval | Other Regulatory Assets Pending Final Regulatory Approval |  |
Regulatory Asset [Line Items] |  |
Total Noncurrent Regulatory Assets | 52.6 | 86.3
Does not earns/earning a return | Pending final regulatory approval | Plant Retirement Costs - Asset Retirement Obligation Costs |  |
Regulatory Asset [Line Items] |  |
Total Noncurrent Regulatory Assets | 25.9 | 357.4
Does not earns/earning a return | Pending final regulatory approval | Storm-Related Costs |  |
Regulatory Asset [Line Items] |  |
Total Noncurrent Regulatory Assets | 408.9 | 300.8
Does not earns/earning a return | Approved for recovery |  |
Regulatory Asset [Line Items] |  |
Total Noncurrent Regulatory Assets | 2,308.2 | $ 2,106.9
Does not earns/earning a return | Approved for recovery | Plant Retirement Costs - Asset Retirement Obligation Costs |  |
Regulatory Asset [Line Items] |  |
Remaining Recovery Period |  | 18 years
Total Noncurrent Regulatory Assets | 330.2 | $ 360.1
Does not earns/earning a return | Approved for recovery | Storm-Related Costs |  |
Regulatory Asset [Line Items] |  |
Remaining Recovery Period |  | 7 years
Total Noncurrent Regulatory Assets | 38.5 | $ 66.5
Does not earns/earning a return | Approved for recovery | Other Regulatory Assets Approved for Recovery |  |
Regulatory Asset [Line Items] |  |
Total Noncurrent Regulatory Assets | 269.1 | $ 240.1
Does not earns/earning a return | Approved for recovery | Cook Plant Nuclear Refueling Outage Levelization |  |
Regulatory Asset [Line Items] |  |
Remaining Recovery Period |  | 3 years
Total Noncurrent Regulatory Assets | 55.7 | $ 43.0
Does not earns/earning a return | Approved for recovery | Pension and OPEB Funded Status |  |
Regulatory Asset [Line Items] |  |
Remaining Recovery Period |  | 12 years
Total Noncurrent Regulatory Assets | 1,054.1 | $ 974.2
Does not earns/earning a return | Approved for recovery | Unamortized Loss on Reacquired Debt |  |
Regulatory Asset [Line Items] |  |
Remaining Recovery Period |  | 24 years
Total Noncurrent Regulatory Assets | 97.2 | $ 90.9
Does not earns/earning a return | Approved for recovery | Postemployment Benefits |  |
Regulatory Asset [Line Items] |  |
Remaining Recovery Period |  | 3 years
Total Noncurrent Regulatory Assets | 30.6 | $ 27.9
INDIANA MICHIGAN POWER COMPANY |  |
Regulatory Asset [Line Items] |  |
Total Current Regulatory Assets | 14.8 | 10.6
Total Noncurrent Regulatory Assets | 406.3 | 548.1
INDIANA MICHIGAN POWER COMPANY | Pending final regulatory approval |  |
Regulatory Asset [Line Items] |  |
Total Noncurrent Regulatory Assets | 33.2 | 115.0
INDIANA MICHIGAN POWER COMPANY | Approved for recovery |  |
Regulatory Asset [Line Items] |  |
Total Noncurrent Regulatory Assets | 373.1 | 433.1
INDIANA MICHIGAN POWER COMPANY | Earns/earning a return | Under-recovered Fuel Costs |  |
Regulatory Asset [Line Items] |  |
Total Current Regulatory Assets | 14.8 | $ 10.6
Remaining Recovery Period |  | 1 year
INDIANA MICHIGAN POWER COMPANY | Earns/earning a return | Pending final regulatory approval |  |
Regulatory Asset [Line Items] |  |
Total Noncurrent Regulatory Assets | 0.2 | $ 6.4
INDIANA MICHIGAN POWER COMPANY | Earns/earning a return | Pending final regulatory approval | Other Regulatory Assets Pending Final Regulatory Approval |  |
Regulatory Asset [Line Items] |  |
Total Noncurrent Regulatory Assets | 0.2 | 6.4
INDIANA MICHIGAN POWER COMPANY | Earns/earning a return | Approved for recovery |  |
Regulatory Asset [Line Items] |  |
Total Noncurrent Regulatory Assets | 229.3 | $ 194.8
INDIANA MICHIGAN POWER COMPANY | Earns/earning a return | Approved for recovery | Plant Retirement Costs - Unrecovered Plant |  |
Regulatory Asset [Line Items] |  |
Remaining Recovery Period |  | 4 years
Total Noncurrent Regulatory Assets | 122.5 | $ 98.0
INDIANA MICHIGAN POWER COMPANY | Earns/earning a return | Approved for recovery | Rockport Plant Dry Sorbent Injection System and Selective Catalytic Reduction |  |
Regulatory Asset [Line Items] |  |
Remaining Recovery Period |  | 4 years
Total Noncurrent Regulatory Assets | 46.9 | $ 37.3
INDIANA MICHIGAN POWER COMPANY | Earns/earning a return | Approved for recovery | Cook Plant Uprate Project |  |
Regulatory Asset [Line Items] |  |
Remaining Recovery Period |  | 9 years
Total Noncurrent Regulatory Assets | 22.9 | $ 20.5
INDIANA MICHIGAN POWER COMPANY | Earns/earning a return | Approved for recovery | Deferred Cook Plant Life Cycle Management Project Costs - Michigan, FERC |  |
Regulatory Asset [Line Items] |  |
Remaining Recovery Period |  | 10 years
Total Noncurrent Regulatory Assets | 11.1 | $ 10.1
INDIANA MICHIGAN POWER COMPANY | Earns/earning a return | Approved for recovery | Cook Plant Turbine - Indiana |  |
Regulatory Asset [Line Items] |  |
Remaining Recovery Period |  | 14 years
Total Noncurrent Regulatory Assets | 8.4 | $ 7.8
INDIANA MICHIGAN POWER COMPANY | Earns/earning a return | Approved for recovery | Other Regulatory Assets Approved for Recovery |  |
Regulatory Asset [Line Items] |  |
Total Noncurrent Regulatory Assets | 17.5 | 21.1
INDIANA MICHIGAN POWER COMPANY | Does not earns/earning a return | Pending final regulatory approval |  |
Regulatory Asset [Line Items] |  |
Total Noncurrent Regulatory Assets | 33.0 | 108.6
INDIANA MICHIGAN POWER COMPANY | Does not earns/earning a return | Pending final regulatory approval | Other Regulatory Assets Pending Final Regulatory Approval |  |
Regulatory Asset [Line Items] |  |
Total Noncurrent Regulatory Assets | 3.3 | 1.6
INDIANA MICHIGAN POWER COMPANY | Does not earns/earning a return | Pending final regulatory approval | Plant Retirement Costs - Asset Retirement Obligation Costs |  |
Regulatory Asset [Line Items] |  |
Total Noncurrent Regulatory Assets | 0.0 | 74.0
INDIANA MICHIGAN POWER COMPANY | Does not earns/earning a return | Pending final regulatory approval | NOLC Costs - Indiana |  |
Regulatory Asset [Line Items] |  |
Total Noncurrent Regulatory Assets | 0.0 | 26.7
INDIANA MICHIGAN POWER COMPANY | Does not earns/earning a return | Pending final regulatory approval | Storm-Related Costs |  |
Regulatory Asset [Line Items] |  |
Total Noncurrent Regulatory Assets | 29.7 | 6.3
INDIANA MICHIGAN POWER COMPANY | Does not earns/earning a return | Approved for recovery |  |
Regulatory Asset [Line Items] |  |
Total Noncurrent Regulatory Assets | 143.8 | $ 238.3
INDIANA MICHIGAN POWER COMPANY | Does not earns/earning a return | Approved for recovery | Storm-Related Costs |  |
Regulatory Asset [Line Items] |  |
Remaining Recovery Period |  | 4 years
Total Noncurrent Regulatory Assets | 3.4 | $ 20.2
INDIANA MICHIGAN POWER COMPANY | Does not earns/earning a return | Approved for recovery | Other Regulatory Assets Approved for Recovery |  |
Regulatory Asset [Line Items] |  |
Total Noncurrent Regulatory Assets | 17.6 | 20.2
INDIANA MICHIGAN POWER COMPANY | Does not earns/earning a return | Approved for recovery | Income Taxes, Net |  |
Regulatory Asset [Line Items] |  |
Total Noncurrent Regulatory Assets | 0.0 | $ 108.8
Regulatory asset, not subject to rate normalization requirements, amount | $ 12.0 |
Regulatory asset, not subject to rate normalization requirements, refund period | 4 years |
INDIANA MICHIGAN POWER COMPANY | Does not earns/earning a return | Approved for recovery | Cook Plant Nuclear Refueling Outage Levelization |  |
Regulatory Asset [Line Items] |  |
Remaining Recovery Period |  | 3 years
Total Noncurrent Regulatory Assets | $ 55.7 | $ 43.0
INDIANA MICHIGAN POWER COMPANY | Does not earns/earning a return | Approved for recovery | Pension and OPEB Funded Status |  |
Regulatory Asset [Line Items] |  |
Remaining Recovery Period |  | 12 years
Total Noncurrent Regulatory Assets | 25.4 | $ 14.6
INDIANA MICHIGAN POWER COMPANY | Does not earns/earning a return | Approved for recovery | Excess SO2 Allowance Inventory - Indiana |  |
Regulatory Asset [Line Items] |  |
Remaining Recovery Period |  | 4 years
Total Noncurrent Regulatory Assets | 14.8 | $ 11.9
INDIANA MICHIGAN POWER COMPANY | Does not earns/earning a return | Approved for recovery | Unamortized Loss on Reacquired Debt |  |
Regulatory Asset [Line Items] |  |
Remaining Recovery Period |  | 24 years
Total Noncurrent Regulatory Assets | 11.8 | $ 10.9
INDIANA MICHIGAN POWER COMPANY | Does not earns/earning a return | Approved for recovery | Postemployment Benefits |  |
Regulatory Asset [Line Items] |  |
Remaining Recovery Period |  | 3 years
Total Noncurrent Regulatory Assets | 7.0 | $ 7.3
INDIANA MICHIGAN POWER COMPANY | Does not earns/earning a return | Approved for recovery | Environmental Cost Rider - Indiana |  |
Regulatory Asset [Line Items] |  |
Remaining Recovery Period |  | 2 years
Total Noncurrent Regulatory Assets | $ 8.1 | $ 1.4

X
- Definition Regulatory Asset, Not Subject to Rate Normalization Requirements. Amount + References No definition available. + Details
Name: | aep_RegulatoryAssetNotSubjectToRateNormalizationRequirements.Amount
Namespace Prefix: | aep_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Regulatory Asset, Not Subject to Rate Normalization Requirements, Refund Period + References No definition available. + Details
Name: | aep_RegulatoryAssetNotSubjectToRateNormalizationRequirementsRefundPeriod
Namespace Prefix: | aep_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amortization period for the recovery of regulatory asset, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References No definition available. + Details
Name: | us-gaap_RegulatoryAssetAmortizationPeriod
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | instant

X
- Definition 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. + References No definition available. + Details
Name: | us-gaap_RegulatoryAssetLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Carrying amount as of the balance sheet date of capitalized costs of regulated entities that are expected to be recovered through revenue sources within one year or the normal operating cycle, if longer. Such costs are capitalized if they meet both of the following criteria: a. It is probable that future revenue in an amount at least equal to the capitalized cost will result from inclusion of that cost in allowable costs for rate-making purposes. b. Based on available evidence, the future revenue will be provided to permit recovery of the previously incurred cost rather than to provide for expected levels of similar future costs. If the revenue will be provided through an automatic rate-adjustment clause, this criterion requires that the regulator's intent clearly be to permit recovery of the previously incurred cost. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 980 -SubTopic 340 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147478742/980-340-50-1 + Details
Name: | us-gaap_RegulatoryAssetsCurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Carrying amount as of the balance sheet date of capitalized costs of regulated entities that are not expected to be recovered through revenue sources within one year or the normal operating cycle if longer. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 980 -SubTopic 340 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147478742/980-340-50-1 + Details
Name: | us-gaap_RegulatoryAssetsNoncurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | aep_RegulatoryAssetsOrLiabilityRegulatoryStatusAxis=aep_RegulatoryAssetsPendingFinalApprovalMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | aep_RegulatoryAssetsOrLiabilityRegulatoryStatusAxis=aep_RegulatoryAssetsFinalApprovalMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | aep_RegulatoryAssetsOrLiabilityReturnStatusAxis=aep_RegulatoryAssetsEarningReturnMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAssetAxis=us-gaap_DeferredFuelCostsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAssetAxis=aep_OtherRegulatoryAssetsPendingFinalRegulatoryApprovalMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAssetAxis=us-gaap_StormCostsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAssetAxis=aep_PlantRetirementCostsAssetRetirementObligationCostsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAssetAxis=aep_PlantRetirementCostsUnrecoveredPlantMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAssetAxis=aep_RockportPlantDrySorbentInjectionSystemAndSelectiveCatalyticReductionMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAssetAxis=aep_OtherRegulatoryAssetsApprovedForRecoveryMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | aep_RegulatoryAssetsOrLiabilityReturnStatusAxis=aep_RegulatoryAssetsNotEarningReturnMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAssetAxis=aep_CookNuclearPlantRefuelingOutageLevelizationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAssetAxis=us-gaap_PensionCostsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAssetAxis=us-gaap_LossOnReacquiredDebtMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAssetAxis=aep_PostemploymentBenefitsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=aep_IndianaMichiganPowerCompanyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAssetAxis=aep_CookPlantUprateProjectMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAssetAxis=aep_DeferredCookPlantLifeCycleManagementProjectCostsMichiganFERCMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAssetAxis=aep_CookPlantTurbineMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAssetAxis=aep_NOLCCostsIndianaMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAssetAxis=aep_IncomeTaxesNetMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAssetAxis=aep_ExcessSO2AllowanceInventoryVirginiaMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAssetAxis=aep_EnvironmentalCostRiderIndianaMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |