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Derivatives and Hedging (Details) gal in Millions, MWh in Millions, MMBTU in Millions | 3 Months Ended | 6 Months Ended | 12 Months Ended
--- | --- | --- | ---
Jun. 30, 2024 USD ($) MWh MMBTU gal | Jun. 30, 2023 USD ($) | Jun. 30, 2024 USD ($) MWh MMBTU gal | Jun. 30, 2023 USD ($) | Dec. 31, 2023 USD ($) MWh MMBTU gal
Cash Collateral Netting |  |  |  |  |  |  |  |  |
Cash Collateral Received Netted Against Risk Management Assets |  | $ 155,000,000 |  |  | $ 155,000,000 |  |  | $ 46,000,000 |
Fair Value of Derivative Instruments |  |  |  |  |  |  |  |  |
Current Risk Management Assets |  | 322,700,000 |  |  | 322,700,000 |  |  | 217,500,000 |
Long-term Risk Management Assets |  | 255,400,000 |  |  | 255,400,000 |  |  | 321,200,000 |
Total Assets |  | 578,100,000 |  |  | 578,100,000 |  |  | 538,700,000 |
Current Risk Management Liabilities |  | 155,000,000.0 |  |  | 155,000,000.0 |  |  | 229,600,000 |
Long-term Risk Management Liabilities |  | 261,400,000 |  |  | 261,400,000 |  |  | 241,800,000 |
Total Liabilities |  | 416,400,000 |  |  | 416,400,000 |  |  | 471,400,000 |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  | 77,000,000.0 |  | $ (34,300,000) | 73,900,000 |  | $ (212,500,000) |  |
Carrying Amount of Hedged Asset (Liability) | [1],[2] | (876,800,000) |  |  | (876,800,000) |  |  | (878,200,000) |
Cumulative Fair Value Hedging Adjustment in the Carrying Amount of the Hedged Asset (Liability) | [1],[2] | 70,400,000 |  |  | 70,400,000 |  |  | 68,400,000 |
Gain (Loss) on Hedging Instruments |  |  |  |  |  |  |  |  |
Gain (Loss) on Fair Value Hedging Instruments | [3] | 18,200,000 |  | (4,200,000) | 1,800,000 |  | 2,700,000 |  |
Gain (Loss) on Fair Value Portion of Long Term Debt | [3] | (18,200,000) |  | 4,200,000 | (1,800,000) |  | (2,700,000) |  |
Collateral Triggering Events [Abstract] |  |  |  |  |  |  |  |  |
Fair Value Of Derivative Liabilities Subject To Cross Acceleration Provisions |  | 97,000,000 |  |  | 97,000,000 |  |  | 107,000,000 |
Fair Value Of Derivative Liabilities Subject To Cross Default Provisions |  | 233,000,000 |  |  | 233,000,000 |  |  | 242,000,000 |
Derivatives and Hedging (Textuals) [Abstract] |  |  |  |  |  |  |  |  |
Hedged Liability, Discontinued Fair Value Hedge, Cumulative Increase (Decrease) |  | (26,000,000) |  |  | (26,000,000) |  |  | (30,000,000) |
AEP Texas Inc. [Member] |  |  |  |  |  |  |  |  |
Fair Value of Derivative Instruments |  |  |  |  |  |  |  |  |
Total Liabilities |  |  |  |  |  |  |  | 2,700,000 |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  | 100,000 |  | (200,000) | 500,000 |  | (600,000) |  |
Appalachian Power Co [Member] |  |  |  |  |  |  |  |  |
Fair Value of Derivative Instruments |  |  |  |  |  |  |  |  |
Current Risk Management Assets |  | 67,700,000 |  |  | 67,700,000 |  |  | 22,400,000 |
Current Risk Management Liabilities |  | 9,000,000.0 |  |  | 9,000,000.0 |  |  | 15,900,000 |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  | 28,600,000 |  | 24,600,000 | 42,600,000 |  | (8,100,000) |  |
Collateral Triggering Events [Abstract] |  |  |  |  |  |  |  |  |
Fair Value Of Derivative Liabilities Subject To Cross Default Provisions |  | 13,000,000 |  |  | 13,000,000 |  |  | 22,000,000 |
Indiana Michigan Power Co [Member] |  |  |  |  |  |  |  |  |
Fair Value of Derivative Instruments |  |  |  |  |  |  |  |  |
Current Risk Management Assets |  | 28,100,000 |  |  | 28,100,000 |  |  | 27,800,000 |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  | 16,300,000 |  | 19,100,000 | (8,900,000) |  | 14,500,000 |  |
Ohio Power Co [Member] |  |  |  |  |  |  |  |  |
Fair Value of Derivative Instruments |  |  |  |  |  |  |  |  |
Current Risk Management Liabilities |  | 6,000,000.0 |  |  | 6,000,000.0 |  |  | 6,800,000 |
Long-term Risk Management Liabilities |  | 37,200,000 |  |  | 37,200,000 |  |  | 43,900,000 |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  | (3,000,000.0) |  | (12,800,000) | 5,600,000 |  | (25,100,000) |  |
Public Service Co Of Oklahoma [Member] |  |  |  |  |  |  |  |  |
Fair Value of Derivative Instruments |  |  |  |  |  |  |  |  |
Current Risk Management Assets |  | 49,400,000 |  |  | 49,400,000 |  |  | 19,000,000.0 |
Current Risk Management Liabilities |  | 19,100,000 |  |  | 19,100,000 |  |  | 28,900,000 |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  | 42,700,000 |  | 40,100,000 | 59,800,000 |  | 56,900,000 |  |
Collateral Triggering Events [Abstract] |  |  |  |  |  |  |  |  |
Fair Value Of Derivative Liabilities Subject To Cross Default Provisions |  | 23,000,000 |  |  | 23,000,000 |  |  | 29,000,000 |
Southwestern Electric Power Co [Member] |  |  |  |  |  |  |  |  |
Fair Value of Derivative Instruments |  |  |  |  |  |  |  |  |
Current Risk Management Assets |  | 38,200,000 |  |  | 38,200,000 |  |  | 11,600,000 |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  | 34,900,000 |  | 32,700,000 | 54,800,000 |  | 43,100,000 |  |
Collateral Triggering Events [Abstract] |  |  |  |  |  |  |  |  |
Fair Value Of Derivative Liabilities Subject To Cross Default Provisions |  | 10,000,000 |  |  | 10,000,000 |  |  | 15,000,000 |
Risk Management Contracts [Member] |  |  |  |  |  |  |  |  |
Fair Value of Derivative Instruments |  |  |  |  |  |  |  |  |
Total Assets | [5] | 435,200,000 | [4] |  | 435,200,000 | [4] |  | 403,900,000 | [6]
Total Liabilities | [5] | 318,700,000 | [4] |  | 318,700,000 | [4] |  | 362,300,000 | [6]
Risk Management Contracts [Member] | AEP Texas Inc. [Member] |  |  |  |  |  |  |  |  |
Fair Value of Derivative Instruments |  |  |  |  |  |  |  |  |
Total Liabilities | [5] |  |  |  |  |  |  | 0 |
Risk Management Contracts [Member] | Appalachian Power Co [Member] |  |  |  |  |  |  |  |  |
Fair Value of Derivative Instruments |  |  |  |  |  |  |  |  |
Total Assets | [5] | 67,700,000 |  |  | 67,700,000 |  |  | 22,400,000 |
Total Liabilities | [5] | 13,300,000 |  |  | 13,300,000 |  |  | 22,500,000 |
Risk Management Contracts [Member] | Indiana Michigan Power Co [Member] |  |  |  |  |  |  |  |  |
Fair Value of Derivative Instruments |  |  |  |  |  |  |  |  |
Total Assets | [5] | 28,100,000 |  |  | 28,100,000 |  |  | 39,600,000 |
Total Liabilities | [5] | 0 |  |  | 0 |  |  | 2,000,000.0 |
Risk Management Contracts [Member] | Ohio Power Co [Member] |  |  |  |  |  |  |  |  |
Fair Value of Derivative Instruments |  |  |  |  |  |  |  |  |
Total Liabilities |  | 43,200,000 | [5] |  | 43,200,000 | [5] |  | 50,700,000 |
Risk Management Contracts [Member] | Public Service Co Of Oklahoma [Member] |  |  |  |  |  |  |  |  |
Fair Value of Derivative Instruments |  |  |  |  |  |  |  |  |
Total Assets | [5] | 49,400,000 |  |  | 49,400,000 |  |  | 19,000,000.0 |
Total Liabilities | [5] | 22,800,000 |  |  | 22,800,000 |  |  | 29,900,000 |
Risk Management Contracts [Member] | Southwestern Electric Power Co [Member] |  |  |  |  |  |  |  |  |
Fair Value of Derivative Instruments |  |  |  |  |  |  |  |  |
Total Assets | [5] | 38,200,000 |  |  | 38,200,000 |  |  | 11,600,000 |
Total Liabilities | [5] | 11,100,000 |  |  | 11,100,000 |  |  | 15,600,000 |
Commodity [Member] |  |  |  |  |  |  |  |  |
Impact of Cash Flow Hedges on the Condensed Balance Sheet |  |  |  |  |  |  |  |  |
AOCI Gain (Loss) Net of Tax |  | 103,700,000 |  |  | 103,700,000 |  |  | 104,900,000 |
Portion Expected to be Reclassified to Net Income During the Next Twelve Months |  |  |  |  | $ 35,500,000 |  |  | 38,300,000 |
Derivatives and Hedging (Textuals) [Abstract] |  |  |  |  |  |  |  |  |
Maximum Term for Exposure to Variability of Future Cash Flows |  |  |  |  | 81 months |  |  |  |
Cross Acceleration Provisions Maximum Third Party Obligation Amount |  | 50,000,000 |  |  | $ 50,000,000 |  |  |  |
Cross Default Provisions Maximum Third Party Obligation Amount |  | 50,000,000 |  |  | 50,000,000 |  |  |  |
Commodity [Member] | AEP Texas Inc. [Member] |  |  |  |  |  |  |  |  |
Impact of Cash Flow Hedges on the Condensed Balance Sheet |  |  |  |  |  |  |  |  |
AOCI Gain (Loss) Net of Tax |  | 0 |  |  | 0 |  |  | 0 |
Portion Expected to be Reclassified to Net Income During the Next Twelve Months |  |  |  |  | 0 |  |  | 0 |
Commodity [Member] | Appalachian Power Co [Member] |  |  |  |  |  |  |  |  |
Impact of Cash Flow Hedges on the Condensed Balance Sheet |  |  |  |  |  |  |  |  |
AOCI Gain (Loss) Net of Tax |  | 0 |  |  | 0 |  |  | 0 |
Portion Expected to be Reclassified to Net Income During the Next Twelve Months |  |  |  |  | 0 |  |  | 0 |
Commodity [Member] | Indiana Michigan Power Co [Member] |  |  |  |  |  |  |  |  |
Impact of Cash Flow Hedges on the Condensed Balance Sheet |  |  |  |  |  |  |  |  |
AOCI Gain (Loss) Net of Tax |  | 0 |  |  | 0 |  |  | 0 |
Portion Expected to be Reclassified to Net Income During the Next Twelve Months |  |  |  |  | 0 |  |  | 0 |
Commodity [Member] | Public Service Co Of Oklahoma [Member] |  |  |  |  |  |  |  |  |
Impact of Cash Flow Hedges on the Condensed Balance Sheet |  |  |  |  |  |  |  |  |
AOCI Gain (Loss) Net of Tax |  | 0 |  |  | 0 |  |  | 0 |
Portion Expected to be Reclassified to Net Income During the Next Twelve Months |  |  |  |  | 0 |  |  | 0 |
Commodity [Member] | Southwestern Electric Power Co [Member] |  |  |  |  |  |  |  |  |
Impact of Cash Flow Hedges on the Condensed Balance Sheet |  |  |  |  |  |  |  |  |
AOCI Gain (Loss) Net of Tax |  | 0 |  |  | 0 |  |  | 0 |
Portion Expected to be Reclassified to Net Income During the Next Twelve Months |  |  |  |  | 0 |  |  | 0 |
Commodity [Member] | Risk Management Contracts [Member] |  |  |  |  |  |  |  |  |
Fair Value of Derivative Instruments |  |  |  |  |  |  |  |  |
Current Risk Management Assets |  | 590,600,000 |  |  | 590,600,000 |  |  | 555,100,000 |
Long-term Risk Management Assets |  | 549,600,000 |  |  | 549,600,000 |  |  | 468,800,000 |
Current Risk Management Liabilities |  | 403,000,000.0 |  |  | 403,000,000.0 |  |  | 588,000,000.0 |
Long-term Risk Management Liabilities |  | 468,100,000 |  |  | 468,100,000 |  |  | 377,600,000 |
Commodity [Member] | Risk Management Contracts [Member] | AEP Texas Inc. [Member] |  |  |  |  |  |  |  |  |
Fair Value of Derivative Instruments |  |  |  |  |  |  |  |  |
Current Risk Management Assets |  | 0 |  |  | 0 |  |  | 0 |
Long-term Risk Management Assets |  | 0 |  |  | 0 |  |  | 0 |
Current Risk Management Liabilities |  | 0 |  |  | 0 |  |  | 200,000 |
Long-term Risk Management Liabilities |  | 0 |  |  | 0 |  |  | 0 |
Commodity [Member] | Risk Management Contracts [Member] | Appalachian Power Co [Member] |  |  |  |  |  |  |  |  |
Fair Value of Derivative Instruments |  |  |  |  |  |  |  |  |
Current Risk Management Assets |  | 72,800,000 |  |  | 72,800,000 |  |  | 24,600,000 |
Long-term Risk Management Assets |  | 800,000 |  |  | 800,000 |  |  | 300,000 |
Current Risk Management Liabilities |  | 15,500,000 |  |  | 15,500,000 |  |  | 18,500,000 |
Long-term Risk Management Liabilities |  | 5,100,000 |  |  | 5,100,000 |  |  | 6,900,000 |
Commodity [Member] | Risk Management Contracts [Member] | Indiana Michigan Power Co [Member] |  |  |  |  |  |  |  |  |
Fair Value of Derivative Instruments |  |  |  |  |  |  |  |  |
Current Risk Management Assets |  | 34,800,000 |  |  | 34,800,000 |  |  | 30,100,000 |
Long-term Risk Management Assets |  | 0 |  |  | 0 |  |  | 12,000,000.0 |
Current Risk Management Liabilities |  | 6,700,000 |  |  | 6,700,000 |  |  | 5,400,000 |
Long-term Risk Management Liabilities |  | 0 |  |  | 0 |  |  | 200,000 |
Commodity [Member] | Risk Management Contracts [Member] | Ohio Power Co [Member] |  |  |  |  |  |  |  |  |
Fair Value of Derivative Instruments |  |  |  |  |  |  |  |  |
Current Risk Management Assets |  | 0 |  |  | 0 |  |  | 0 |
Long-term Risk Management Assets |  | 0 |  |  | 0 |  |  | 0 |
Current Risk Management Liabilities |  | 6,000,000.0 |  |  | 6,000,000.0 |  |  | 6,900,000 |
Long-term Risk Management Liabilities |  | 37,200,000 |  |  | 37,200,000 |  |  | 43,900,000 |
Commodity [Member] | Risk Management Contracts [Member] | Public Service Co Of Oklahoma [Member] |  |  |  |  |  |  |  |  |
Fair Value of Derivative Instruments |  |  |  |  |  |  |  |  |
Current Risk Management Assets |  | 49,800,000 |  |  | 49,800,000 |  |  | 19,700,000 |
Long-term Risk Management Assets |  | 900,000 |  |  | 900,000 |  |  | 0 |
Current Risk Management Liabilities |  | 19,500,000 |  |  | 19,500,000 |  |  | 29,700,000 |
Long-term Risk Management Liabilities |  | 4,600,000 |  |  | 4,600,000 |  |  | 1,000,000.0 |
Commodity [Member] | Risk Management Contracts [Member] | Southwestern Electric Power Co [Member] |  |  |  |  |  |  |  |  |
Fair Value of Derivative Instruments |  |  |  |  |  |  |  |  |
Current Risk Management Assets |  | 38,600,000 |  |  | 38,600,000 |  |  | 12,000,000.0 |
Long-term Risk Management Assets |  | 0 |  |  | 0 |  |  | 500,000 |
Current Risk Management Liabilities |  | 9,800,000 |  |  | 9,800,000 |  |  | 14,900,000 |
Long-term Risk Management Liabilities |  | 1,700,000 |  |  | 1,700,000 |  |  | 1,700,000 |
Commodity [Member] | Hedging Contracts [Member] |  |  |  |  |  |  |  |  |
Fair Value of Derivative Instruments |  |  |  |  |  |  |  |  |
Current Risk Management Assets |  | 48,600,000 |  |  | 48,600,000 |  |  | 56,700,000 |
Long-term Risk Management Assets |  | 86,900,000 |  |  | 86,900,000 |  |  | 86,800,000 |
Current Risk Management Liabilities |  | 3,600,000 |  |  | 3,600,000 |  |  | 8,200,000 |
Long-term Risk Management Liabilities |  | 300,000 |  |  | 300,000 |  |  | 2,200,000 |
Commodity [Member] | Hedging Contracts [Member] | AEP Texas Inc. [Member] |  |  |  |  |  |  |  |  |
Fair Value of Derivative Instruments |  |  |  |  |  |  |  |  |
Current Risk Management Assets |  | 0 |  |  | 0 |  |  | 0 |
Long-term Risk Management Assets |  | 0 |  |  | 0 |  |  | 0 |
Current Risk Management Liabilities |  | 0 |  |  | 0 |  |  | 0 |
Long-term Risk Management Liabilities |  | 0 |  |  | 0 |  |  | 0 |
Commodity [Member] | Hedging Contracts [Member] | Appalachian Power Co [Member] |  |  |  |  |  |  |  |  |
Fair Value of Derivative Instruments |  |  |  |  |  |  |  |  |
Current Risk Management Assets |  | 0 |  |  | 0 |  |  | 0 |
Long-term Risk Management Assets |  | 0 |  |  | 0 |  |  | 0 |
Current Risk Management Liabilities |  | 0 |  |  | 0 |  |  | 0 |
Long-term Risk Management Liabilities |  | 0 |  |  | 0 |  |  | 0 |
Commodity [Member] | Hedging Contracts [Member] | Indiana Michigan Power Co [Member] |  |  |  |  |  |  |  |  |
Fair Value of Derivative Instruments |  |  |  |  |  |  |  |  |
Current Risk Management Assets |  | 0 |  |  | 0 |  |  | 0 |
Long-term Risk Management Assets |  | 0 |  |  | 0 |  |  | 0 |
Current Risk Management Liabilities |  | 0 |  |  | 0 |  |  | 0 |
Long-term Risk Management Liabilities |  | 0 |  |  | 0 |  |  | 0 |
Commodity [Member] | Hedging Contracts [Member] | Ohio Power Co [Member] |  |  |  |  |  |  |  |  |
Fair Value of Derivative Instruments |  |  |  |  |  |  |  |  |
Current Risk Management Assets |  | 0 |  |  | 0 |  |  | 0 |
Long-term Risk Management Assets |  | 0 |  |  | 0 |  |  | 0 |
Current Risk Management Liabilities |  | 0 |  |  | 0 |  |  | 0 |
Long-term Risk Management Liabilities |  | 0 |  |  | 0 |  |  | 0 |
Commodity [Member] | Hedging Contracts [Member] | Public Service Co Of Oklahoma [Member] |  |  |  |  |  |  |  |  |
Fair Value of Derivative Instruments |  |  |  |  |  |  |  |  |
Current Risk Management Assets |  | 0 |  |  | 0 |  |  | 0 |
Long-term Risk Management Assets |  | 0 |  |  | 0 |  |  | 0 |
Current Risk Management Liabilities |  | 0 |  |  | 0 |  |  | 0 |
Long-term Risk Management Liabilities |  | 0 |  |  | 0 |  |  | 0 |
Commodity [Member] | Hedging Contracts [Member] | Southwestern Electric Power Co [Member] |  |  |  |  |  |  |  |  |
Fair Value of Derivative Instruments |  |  |  |  |  |  |  |  |
Current Risk Management Assets |  | 0 |  |  | 0 |  |  | 0 |
Long-term Risk Management Assets |  | 0 |  |  | 0 |  |  | 0 |
Current Risk Management Liabilities |  | 0 |  |  | 0 |  |  | 0 |
Long-term Risk Management Liabilities |  | 0 |  |  | 0 |  |  | 0 |
Interest Rate [Member] |  |  |  |  |  |  |  |  |
Commodity: |  |  |  |  |  |  |  |  |
Derivative, Notional Amount |  | 1,350,000,000 |  |  | 1,350,000,000 |  |  | 1,300,000,000 |
Impact of Cash Flow Hedges on the Condensed Balance Sheet |  |  |  |  |  |  |  |  |
AOCI Gain (Loss) Net of Tax |  | 9,300,000 |  |  | 9,300,000 |  |  | (8,100,000) |
Portion Expected to be Reclassified to Net Income During the Next Twelve Months |  |  |  |  | 4,300,000 |  |  | 3,200,000 |
Interest Rate [Member] | AEP Texas Inc. [Member] |  |  |  |  |  |  |  |  |
Commodity: |  |  |  |  |  |  |  |  |
Derivative, Notional Amount |  | 0 |  |  | 0 |  |  | 150,000,000.0 |
Impact of Cash Flow Hedges on the Condensed Balance Sheet |  |  |  |  |  |  |  |  |
AOCI Gain (Loss) Net of Tax |  | 6,600,000 |  |  | 6,600,000 |  |  | 500,000 |
Portion Expected to be Reclassified to Net Income During the Next Twelve Months |  |  |  |  | 700,000 |  |  | 200,000 |
Interest Rate [Member] | Appalachian Power Co [Member] |  |  |  |  |  |  |  |  |
Commodity: |  |  |  |  |  |  |  |  |
Derivative, Notional Amount |  | 0 |  |  | 0 |  |  | 0 |
Impact of Cash Flow Hedges on the Condensed Balance Sheet |  |  |  |  |  |  |  |  |
AOCI Gain (Loss) Net of Tax |  | 5,500,000 |  |  | 5,500,000 |  |  | 5,900,000 |
Portion Expected to be Reclassified to Net Income During the Next Twelve Months |  |  |  |  | 800,000 |  |  | 800,000 |
Interest Rate [Member] | Indiana Michigan Power Co [Member] |  |  |  |  |  |  |  |  |
Commodity: |  |  |  |  |  |  |  |  |
Derivative, Notional Amount |  | 0 |  |  | 0 |  |  | 0 |
Impact of Cash Flow Hedges on the Condensed Balance Sheet |  |  |  |  |  |  |  |  |
AOCI Gain (Loss) Net of Tax |  | (5,300,000) |  |  | (5,300,000) |  |  | (5,500,000) |
Portion Expected to be Reclassified to Net Income During the Next Twelve Months |  |  |  |  | (400,000) |  |  | (400,000) |
Interest Rate [Member] | Ohio Power Co [Member] |  |  |  |  |  |  |  |  |
Commodity: |  |  |  |  |  |  |  |  |
Derivative, Notional Amount |  | 0 |  |  | 0 |  |  | 0 |
Interest Rate [Member] | Public Service Co Of Oklahoma [Member] |  |  |  |  |  |  |  |  |
Commodity: |  |  |  |  |  |  |  |  |
Derivative, Notional Amount |  | 0 |  |  | 0 |  |  | 0 |
Impact of Cash Flow Hedges on the Condensed Balance Sheet |  |  |  |  |  |  |  |  |
AOCI Gain (Loss) Net of Tax |  | (200,000) |  |  | (200,000) |  |  | (200,000) |
Portion Expected to be Reclassified to Net Income During the Next Twelve Months |  |  |  |  | 0 |  |  | 0 |
Interest Rate [Member] | Southwestern Electric Power Co [Member] |  |  |  |  |  |  |  |  |
Commodity: |  |  |  |  |  |  |  |  |
Derivative, Notional Amount |  | 0 |  |  | 0 |  |  | 0 |
Impact of Cash Flow Hedges on the Condensed Balance Sheet |  |  |  |  |  |  |  |  |
AOCI Gain (Loss) Net of Tax |  | 1,200,000 |  |  | 1,200,000 |  |  | 1,300,000 |
Portion Expected to be Reclassified to Net Income During the Next Twelve Months |  |  |  |  | 300,000 |  |  | 300,000 |
Interest Rate [Member] | Hedging Contracts [Member] |  |  |  |  |  |  |  |  |
Fair Value of Derivative Instruments |  |  |  |  |  |  |  |  |
Current Risk Management Assets |  | 10,300,000 |  |  | 10,300,000 |  |  | 0 |
Long-term Risk Management Assets |  | 0 |  |  | 0 |  |  | 0 |
Current Risk Management Liabilities |  | 43,300,000 |  |  | 43,300,000 |  |  | 50,500,000 |
Long-term Risk Management Liabilities |  | 53,400,000 |  |  | 53,400,000 |  |  | 56,900,000 |
Interest Rate [Member] | Hedging Contracts [Member] | AEP Texas Inc. [Member] |  |  |  |  |  |  |  |  |
Fair Value of Derivative Instruments |  |  |  |  |  |  |  |  |
Current Risk Management Assets |  | 0 |  |  | 0 |  |  | 0 |
Long-term Risk Management Assets |  | 0 |  |  | 0 |  |  | 0 |
Current Risk Management Liabilities |  | 0 |  |  | 0 |  |  | 2,700,000 |
Long-term Risk Management Liabilities |  | 0 |  |  | 0 |  |  | 0 |
Interest Rate [Member] | Hedging Contracts [Member] | Appalachian Power Co [Member] |  |  |  |  |  |  |  |  |
Fair Value of Derivative Instruments |  |  |  |  |  |  |  |  |
Current Risk Management Assets |  | 0 |  |  | 0 |  |  | 0 |
Long-term Risk Management Assets |  | 0 |  |  | 0 |  |  | 0 |
Current Risk Management Liabilities |  | 0 |  |  | 0 |  |  | 0 |
Long-term Risk Management Liabilities |  | 0 |  |  | 0 |  |  | 0 |
Interest Rate [Member] | Hedging Contracts [Member] | Indiana Michigan Power Co [Member] |  |  |  |  |  |  |  |  |
Fair Value of Derivative Instruments |  |  |  |  |  |  |  |  |
Current Risk Management Assets |  | 0 |  |  | 0 |  |  | 0 |
Long-term Risk Management Assets |  | 0 |  |  | 0 |  |  | 0 |
Current Risk Management Liabilities |  | 0 |  |  | 0 |  |  | 0 |
Long-term Risk Management Liabilities |  | 0 |  |  | 0 |  |  | 0 |
Interest Rate [Member] | Hedging Contracts [Member] | Ohio Power Co [Member] |  |  |  |  |  |  |  |  |
Fair Value of Derivative Instruments |  |  |  |  |  |  |  |  |
Current Risk Management Assets |  | 0 |  |  | 0 |  |  | 0 |
Long-term Risk Management Assets |  | 0 |  |  | 0 |  |  | 0 |
Current Risk Management Liabilities |  | 0 |  |  | 0 |  |  | 0 |
Long-term Risk Management Liabilities |  | 0 |  |  | 0 |  |  | 0 |
Interest Rate [Member] | Hedging Contracts [Member] | Public Service Co Of Oklahoma [Member] |  |  |  |  |  |  |  |  |
Fair Value of Derivative Instruments |  |  |  |  |  |  |  |  |
Current Risk Management Assets |  | 0 |  |  | 0 |  |  | 0 |
Long-term Risk Management Assets |  | 0 |  |  | 0 |  |  | 0 |
Current Risk Management Liabilities |  | 0 |  |  | 0 |  |  | 0 |
Long-term Risk Management Liabilities |  | 0 |  |  | 0 |  |  | 0 |
Interest Rate [Member] | Hedging Contracts [Member] | Southwestern Electric Power Co [Member] |  |  |  |  |  |  |  |  |
Fair Value of Derivative Instruments |  |  |  |  |  |  |  |  |
Current Risk Management Assets |  | 0 |  |  | 0 |  |  | 0 |
Long-term Risk Management Assets |  | 0 |  |  | 0 |  |  | 0 |
Current Risk Management Liabilities |  | 0 |  |  | 0 |  |  | 0 |
Long-term Risk Management Liabilities |  | 0 |  |  | 0 |  |  | 0 |
Gross Amounts of Risk Management Assets/Liabilities Recognized [Member] |  |  |  |  |  |  |  |  |
Fair Value of Derivative Instruments |  |  |  |  |  |  |  |  |
Current Risk Management Assets |  | 649,500,000 |  |  | 649,500,000 |  |  | 611,800,000 |
Long-term Risk Management Assets |  | 636,500,000 |  |  | 636,500,000 |  |  | 555,600,000 |
Total Assets |  | 1,286,000,000 |  |  | 1,286,000,000 |  |  | 1,167,400,000 |
Current Risk Management Liabilities |  | 449,900,000 |  |  | 449,900,000 |  |  | 646,700,000 |
Long-term Risk Management Liabilities |  | 521,800,000 |  |  | 521,800,000 |  |  | 436,700,000 |
Total Liabilities |  | 971,700,000 |  |  | 971,700,000 |  |  | 1,083,400,000 |
Total MTM Derivative Contract Net Assets (Liabilities) |  | 314,300,000 |  |  | 314,300,000 |  |  | 84,000,000.0 |
Gross Amounts of Risk Management Assets/Liabilities Recognized [Member] | AEP Texas Inc. [Member] |  |  |  |  |  |  |  |  |
Fair Value of Derivative Instruments |  |  |  |  |  |  |  |  |
Current Risk Management Assets |  | 0 |  |  | 0 |  |  | 0 |
Long-term Risk Management Assets |  | 0 |  |  | 0 |  |  | 0 |
Total Assets |  | 0 |  |  | 0 |  |  | 0 |
Current Risk Management Liabilities |  | 0 |  |  | 0 |  |  | 2,900,000 |
Long-term Risk Management Liabilities |  | 0 |  |  | 0 |  |  | 0 |
Total Liabilities |  | 0 |  |  | 0 |  |  | 2,900,000 |
Total MTM Derivative Contract Net Assets (Liabilities) |  | 0 |  |  | 0 |  |  | (2,900,000) |
Gross Amounts of Risk Management Assets/Liabilities Recognized [Member] | Appalachian Power Co [Member] |  |  |  |  |  |  |  |  |
Fair Value of Derivative Instruments |  |  |  |  |  |  |  |  |
Current Risk Management Assets |  | 72,800,000 |  |  | 72,800,000 |  |  | 24,600,000 |
Long-term Risk Management Assets |  | 800,000 |  |  | 800,000 |  |  | 300,000 |
Total Assets |  | 73,600,000 |  |  | 73,600,000 |  |  | 24,900,000 |
Current Risk Management Liabilities |  | 15,500,000 |  |  | 15,500,000 |  |  | 18,500,000 |
Long-term Risk Management Liabilities |  | 5,100,000 |  |  | 5,100,000 |  |  | 6,900,000 |
Total Liabilities |  | 20,600,000 |  |  | 20,600,000 |  |  | 25,400,000 |
Total MTM Derivative Contract Net Assets (Liabilities) |  | 53,000,000.0 |  |  | 53,000,000.0 |  |  | (500,000) |
Gross Amounts of Risk Management Assets/Liabilities Recognized [Member] | Indiana Michigan Power Co [Member] |  |  |  |  |  |  |  |  |
Fair Value of Derivative Instruments |  |  |  |  |  |  |  |  |
Current Risk Management Assets |  | 34,800,000 |  |  | 34,800,000 |  |  | 30,100,000 |
Long-term Risk Management Assets |  | 0 |  |  | 0 |  |  | 12,000,000.0 |
Total Assets |  | 34,800,000 |  |  | 34,800,000 |  |  | 42,100,000 |
Current Risk Management Liabilities |  | 6,700,000 |  |  | 6,700,000 |  |  | 5,400,000 |
Long-term Risk Management Liabilities |  | 0 |  |  | 0 |  |  | 200,000 |
Total Liabilities |  | 6,700,000 |  |  | 6,700,000 |  |  | 5,600,000 |
Total MTM Derivative Contract Net Assets (Liabilities) |  | 28,100,000 |  |  | 28,100,000 |  |  | 36,500,000 |
Gross Amounts of Risk Management Assets/Liabilities Recognized [Member] | Ohio Power Co [Member] |  |  |  |  |  |  |  |  |
Fair Value of Derivative Instruments |  |  |  |  |  |  |  |  |
Current Risk Management Assets |  | 0 |  |  | 0 |  |  | 0 |
Long-term Risk Management Assets |  | 0 |  |  | 0 |  |  | 0 |
Total Assets |  | 0 |  |  | 0 |  |  | 0 |
Current Risk Management Liabilities |  | 6,000,000.0 |  |  | 6,000,000.0 |  |  | 6,900,000 |
Long-term Risk Management Liabilities |  | 37,200,000 |  |  | 37,200,000 |  |  | 43,900,000 |
Total Liabilities |  | 43,200,000 |  |  | 43,200,000 |  |  | 50,800,000 |
Total MTM Derivative Contract Net Assets (Liabilities) |  | (43,200,000) |  |  | (43,200,000) |  |  | (50,800,000) |
Gross Amounts of Risk Management Assets/Liabilities Recognized [Member] | Public Service Co Of Oklahoma [Member] |  |  |  |  |  |  |  |  |
Fair Value of Derivative Instruments |  |  |  |  |  |  |  |  |
Current Risk Management Assets |  | 49,800,000 |  |  | 49,800,000 |  |  | 19,700,000 |
Long-term Risk Management Assets |  | 900,000 |  |  | 900,000 |  |  | 0 |
Total Assets |  | 50,700,000 |  |  | 50,700,000 |  |  | 19,700,000 |
Current Risk Management Liabilities |  | 19,500,000 |  |  | 19,500,000 |  |  | 29,700,000 |
Long-term Risk Management Liabilities |  | 4,600,000 |  |  | 4,600,000 |  |  | 1,000,000.0 |
Total Liabilities |  | 24,100,000 |  |  | 24,100,000 |  |  | 30,700,000 |
Total MTM Derivative Contract Net Assets (Liabilities) |  | 26,600,000 |  |  | 26,600,000 |  |  | (11,000,000.0) |
Gross Amounts of Risk Management Assets/Liabilities Recognized [Member] | Southwestern Electric Power Co [Member] |  |  |  |  |  |  |  |  |
Fair Value of Derivative Instruments |  |  |  |  |  |  |  |  |
Current Risk Management Assets |  | 38,600,000 |  |  | 38,600,000 |  |  | 12,000,000.0 |
Long-term Risk Management Assets |  | 0 |  |  | 0 |  |  | 500,000 |
Total Assets |  | 38,600,000 |  |  | 38,600,000 |  |  | 12,500,000 |
Current Risk Management Liabilities |  | 9,800,000 |  |  | 9,800,000 |  |  | 14,900,000 |
Long-term Risk Management Liabilities |  | 1,700,000 |  |  | 1,700,000 |  |  | 1,700,000 |
Total Liabilities |  | 11,500,000 |  |  | 11,500,000 |  |  | 16,600,000 |
Total MTM Derivative Contract Net Assets (Liabilities) |  | 27,100,000 |  |  | 27,100,000 |  |  | (4,100,000) |
Gross Amounts Offset in the Statement of Financial Position [Member] |  |  |  |  |  |  |  |  |
Fair Value of Derivative Instruments |  |  |  |  |  |  |  |  |
Current Risk Management Assets |  | (326,800,000) |  |  | (326,800,000) |  |  | (394,300,000) |
Long-term Risk Management Assets |  | (381,100,000) |  |  | (381,100,000) |  |  | (234,400,000) |
Current Risk Management Liabilities |  | (294,900,000) |  |  | (294,900,000) |  |  | (417,100,000) |
Long-term Risk Management Liabilities |  | (260,400,000) |  |  | (260,400,000) |  |  | (194,900,000) |
Gross Amounts Offset in the Statement of Financial Position [Member] | AEP Texas Inc. [Member] |  |  |  |  |  |  |  |  |
Fair Value of Derivative Instruments |  |  |  |  |  |  |  |  |
Current Risk Management Assets |  | 0 |  |  | 0 |  |  | 0 |
Long-term Risk Management Assets |  | 0 |  |  | 0 |  |  | 0 |
Current Risk Management Liabilities |  | 0 |  |  | 0 |  |  | (200,000) |
Long-term Risk Management Liabilities |  | 0 |  |  | 0 |  |  | 0 |
Gross Amounts Offset in the Statement of Financial Position [Member] | Appalachian Power Co [Member] |  |  |  |  |  |  |  |  |
Fair Value of Derivative Instruments |  |  |  |  |  |  |  |  |
Current Risk Management Assets |  | (5,100,000) |  |  | (5,100,000) |  |  | (2,200,000) |
Long-term Risk Management Assets |  | (800,000) |  |  | (800,000) |  |  | (300,000) |
Current Risk Management Liabilities |  | (6,500,000) |  |  | (6,500,000) |  |  | (2,600,000) |
Long-term Risk Management Liabilities |  | (800,000) |  |  | (800,000) |  |  | (300,000) |
Gross Amounts Offset in the Statement of Financial Position [Member] | Indiana Michigan Power Co [Member] |  |  |  |  |  |  |  |  |
Fair Value of Derivative Instruments |  |  |  |  |  |  |  |  |
Current Risk Management Assets |  | (6,700,000) |  |  | (6,700,000) |  |  | (2,300,000) |
Long-term Risk Management Assets |  | 0 |  |  | 0 |  |  | (200,000) |
Current Risk Management Liabilities |  | (6,700,000) |  |  | (6,700,000) |  |  | (3,400,000) |
Long-term Risk Management Liabilities |  | 0 |  |  | 0 |  |  | (200,000) |
Gross Amounts Offset in the Statement of Financial Position [Member] | Ohio Power Co [Member] |  |  |  |  |  |  |  |  |
Fair Value of Derivative Instruments |  |  |  |  |  |  |  |  |
Current Risk Management Assets |  | 0 |  |  | 0 |  |  | 0 |
Long-term Risk Management Assets |  | 0 |  |  | 0 |  |  | 0 |
Current Risk Management Liabilities |  | 0 |  |  | 0 |  |  | (100,000) |
Long-term Risk Management Liabilities |  | 0 |  |  | 0 |  |  | 0 |
Gross Amounts Offset in the Statement of Financial Position [Member] | Public Service Co Of Oklahoma [Member] |  |  |  |  |  |  |  |  |
Fair Value of Derivative Instruments |  |  |  |  |  |  |  |  |
Current Risk Management Assets |  | (400,000) |  |  | (400,000) |  |  | (700,000) |
Long-term Risk Management Assets |  | (900,000) |  |  | (900,000) |  |  | 0 |
Current Risk Management Liabilities |  | (400,000) |  |  | (400,000) |  |  | (800,000) |
Long-term Risk Management Liabilities |  | (900,000) |  |  | (900,000) |  |  | 0 |
Gross Amounts Offset in the Statement of Financial Position [Member] | Southwestern Electric Power Co [Member] |  |  |  |  |  |  |  |  |
Fair Value of Derivative Instruments |  |  |  |  |  |  |  |  |
Current Risk Management Assets |  | (400,000) |  |  | (400,000) |  |  | (400,000) |
Long-term Risk Management Assets |  | 0 |  |  | 0 |  |  | (500,000) |
Current Risk Management Liabilities |  | (400,000) |  |  | (400,000) |  |  | (500,000) |
Long-term Risk Management Liabilities |  | 0 |  |  | 0 |  |  | (500,000) |
Net Amounts of Assets/Liabilities Presented in the Statement of Financial Position [Member] |  |  |  |  |  |  |  |  |
Fair Value of Derivative Instruments |  |  |  |  |  |  |  |  |
Current Risk Management Assets |  | 322,700,000 |  |  | 322,700,000 |  |  | 217,500,000 |
Long-term Risk Management Assets |  | 255,400,000 |  |  | 255,400,000 |  |  | 321,200,000 |
Total Assets |  | 578,100,000 |  |  | 578,100,000 |  |  | 538,700,000 |
Current Risk Management Liabilities |  | 155,000,000.0 |  |  | 155,000,000.0 |  |  | 229,600,000 |
Long-term Risk Management Liabilities |  | 261,400,000 |  |  | 261,400,000 |  |  | 241,800,000 |
Total Liabilities |  | 416,400,000 |  |  | 416,400,000 |  |  | 471,400,000 |
Total MTM Derivative Contract Net Assets (Liabilities) |  | 161,700,000 |  |  | 161,700,000 |  |  | 67,300,000 |
Net Amounts of Assets/Liabilities Presented in the Statement of Financial Position [Member] | AEP Texas Inc. [Member] |  |  |  |  |  |  |  |  |
Fair Value of Derivative Instruments |  |  |  |  |  |  |  |  |
Current Risk Management Assets |  | 0 |  |  | 0 |  |  | 0 |
Long-term Risk Management Assets |  | 0 |  |  | 0 |  |  | 0 |
Total Assets |  | 0 |  |  | 0 |  |  | 0 |
Current Risk Management Liabilities |  | 0 |  |  | 0 |  |  | 2,700,000 |
Long-term Risk Management Liabilities |  | 0 |  |  | 0 |  |  | 0 |
Total Liabilities |  | 0 |  |  | 0 |  |  | 2,700,000 |
Total MTM Derivative Contract Net Assets (Liabilities) |  | 0 |  |  | 0 |  |  | (2,700,000) |
Net Amounts of Assets/Liabilities Presented in the Statement of Financial Position [Member] | Appalachian Power Co [Member] |  |  |  |  |  |  |  |  |
Fair Value of Derivative Instruments |  |  |  |  |  |  |  |  |
Current Risk Management Assets |  | 67,700,000 |  |  | 67,700,000 |  |  | 22,400,000 |
Long-term Risk Management Assets |  | 0 |  |  | 0 |  |  | 0 |
Total Assets |  | 67,700,000 |  |  | 67,700,000 |  |  | 22,400,000 |
Current Risk Management Liabilities |  | 9,000,000.0 |  |  | 9,000,000.0 |  |  | 15,900,000 |
Long-term Risk Management Liabilities |  | 4,300,000 |  |  | 4,300,000 |  |  | 6,600,000 |
Total Liabilities |  | 13,300,000 |  |  | 13,300,000 |  |  | 22,500,000 |
Total MTM Derivative Contract Net Assets (Liabilities) |  | 54,400,000 |  |  | 54,400,000 |  |  | (100,000) |
Net Amounts of Assets/Liabilities Presented in the Statement of Financial Position [Member] | Indiana Michigan Power Co [Member] |  |  |  |  |  |  |  |  |
Fair Value of Derivative Instruments |  |  |  |  |  |  |  |  |
Current Risk Management Assets |  | 28,100,000 |  |  | 28,100,000 |  |  | 27,800,000 |
Long-term Risk Management Assets |  | 0 |  |  | 0 |  |  | 11,800,000 |
Total Assets |  | 28,100,000 |  |  | 28,100,000 |  |  | 39,600,000 |
Current Risk Management Liabilities |  | 0 |  |  | 0 |  |  | 2,000,000.0 |
Long-term Risk Management Liabilities |  | 0 |  |  | 0 |  |  | 0 |
Total Liabilities |  | 0 |  |  | 0 |  |  | 2,000,000.0 |
Total MTM Derivative Contract Net Assets (Liabilities) |  | 28,100,000 |  |  | 28,100,000 |  |  | 37,600,000 |
Net Amounts of Assets/Liabilities Presented in the Statement of Financial Position [Member] | Ohio Power Co [Member] |  |  |  |  |  |  |  |  |
Fair Value of Derivative Instruments |  |  |  |  |  |  |  |  |
Current Risk Management Assets |  | 0 |  |  | 0 |  |  | 0 |
Long-term Risk Management Assets |  | 0 |  |  | 0 |  |  | 0 |
Total Assets |  | 0 |  |  | 0 |  |  | 0 |
Current Risk Management Liabilities |  | 6,000,000.0 |  |  | 6,000,000.0 |  |  | 6,800,000 |
Long-term Risk Management Liabilities |  | 37,200,000 |  |  | 37,200,000 |  |  | 43,900,000 |
Total Liabilities |  | 43,200,000 |  |  | 43,200,000 |  |  | 50,700,000 |
Total MTM Derivative Contract Net Assets (Liabilities) |  | (43,200,000) |  |  | (43,200,000) |  |  | (50,700,000) |
Net Amounts of Assets/Liabilities Presented in the Statement of Financial Position [Member] | Public Service Co Of Oklahoma [Member] |  |  |  |  |  |  |  |  |
Fair Value of Derivative Instruments |  |  |  |  |  |  |  |  |
Current Risk Management Assets |  | 49,400,000 |  |  | 49,400,000 |  |  | 19,000,000.0 |
Long-term Risk Management Assets |  | 0 |  |  | 0 |  |  | 0 |
Total Assets |  | 49,400,000 |  |  | 49,400,000 |  |  | 19,000,000.0 |
Current Risk Management Liabilities |  | 19,100,000 |  |  | 19,100,000 |  |  | 28,900,000 |
Long-term Risk Management Liabilities |  | 3,700,000 |  |  | 3,700,000 |  |  | 1,000,000.0 |
Total Liabilities |  | 22,800,000 |  |  | 22,800,000 |  |  | 29,900,000 |
Total MTM Derivative Contract Net Assets (Liabilities) |  | 26,600,000 |  |  | 26,600,000 |  |  | (10,900,000) |
Net Amounts of Assets/Liabilities Presented in the Statement of Financial Position [Member] | Southwestern Electric Power Co [Member] |  |  |  |  |  |  |  |  |
Fair Value of Derivative Instruments |  |  |  |  |  |  |  |  |
Current Risk Management Assets |  | 38,200,000 |  |  | 38,200,000 |  |  | 11,600,000 |
Long-term Risk Management Assets |  | 0 |  |  | 0 |  |  | 0 |
Total Assets |  | 38,200,000 |  |  | 38,200,000 |  |  | 11,600,000 |
Current Risk Management Liabilities |  | 9,400,000 |  |  | 9,400,000 |  |  | 14,400,000 |
Long-term Risk Management Liabilities |  | 1,700,000 |  |  | 1,700,000 |  |  | 1,200,000 |
Total Liabilities |  | 11,100,000 |  |  | 11,100,000 |  |  | 15,600,000 |
Total MTM Derivative Contract Net Assets (Liabilities) |  | $ 27,100,000 |  |  | $ 27,100,000 |  |  | $ (4,000,000.0) |
Power [Member] |  |  |  |  |  |  |  |  |
Commodity: |  |  |  |  |  |  |  |  |
Derivative, Energy Notional Amount | MWh |  | 339.4 |  |  | 339.4 |  |  | 246.8 |
Power [Member] | AEP Texas Inc. [Member] |  |  |  |  |  |  |  |  |
Commodity: |  |  |  |  |  |  |  |  |
Derivative, Energy Notional Amount | MWh |  | 0.0 |  |  | 0.0 |  |  | 0.0 |
Power [Member] | Appalachian Power Co [Member] |  |  |  |  |  |  |  |  |
Commodity: |  |  |  |  |  |  |  |  |
Derivative, Energy Notional Amount | MWh |  | 51.5 |  |  | 51.5 |  |  | 16.8 |
Power [Member] | Indiana Michigan Power Co [Member] |  |  |  |  |  |  |  |  |
Commodity: |  |  |  |  |  |  |  |  |
Derivative, Energy Notional Amount | MWh |  | 12.6 |  |  | 12.6 |  |  | 5.9 |
Power [Member] | Ohio Power Co [Member] |  |  |  |  |  |  |  |  |
Commodity: |  |  |  |  |  |  |  |  |
Derivative, Energy Notional Amount | MWh |  | 2.1 |  |  | 2.1 |  |  | 2.2 |
Power [Member] | Public Service Co Of Oklahoma [Member] |  |  |  |  |  |  |  |  |
Commodity: |  |  |  |  |  |  |  |  |
Derivative, Energy Notional Amount | MWh |  | 11.5 |  |  | 11.5 |  |  | 4.1 |
Power [Member] | Southwestern Electric Power Co [Member] |  |  |  |  |  |  |  |  |
Commodity: |  |  |  |  |  |  |  |  |
Derivative, Energy Notional Amount | MWh |  | 9.8 |  |  | 9.8 |  |  | 2.9 |
Natural Gas [Member] |  |  |  |  |  |  |  |  |
Commodity: |  |  |  |  |  |  |  |  |
Derivative, Energy Notional Amount | MMBTU |  | 170.7 |  |  | 170.7 |  |  | 151.6 |
Natural Gas [Member] | AEP Texas Inc. [Member] |  |  |  |  |  |  |  |  |
Commodity: |  |  |  |  |  |  |  |  |
Derivative, Energy Notional Amount | MMBTU |  | 0.0 |  |  | 0.0 |  |  | 0.0 |
Natural Gas [Member] | Appalachian Power Co [Member] |  |  |  |  |  |  |  |  |
Commodity: |  |  |  |  |  |  |  |  |
Derivative, Energy Notional Amount | MMBTU |  | 47.5 |  |  | 47.5 |  |  | 37.3 |
Natural Gas [Member] | Indiana Michigan Power Co [Member] |  |  |  |  |  |  |  |  |
Commodity: |  |  |  |  |  |  |  |  |
Derivative, Energy Notional Amount | MMBTU |  | 0.0 |  |  | 0.0 |  |  | 0.0 |
Natural Gas [Member] | Ohio Power Co [Member] |  |  |  |  |  |  |  |  |
Commodity: |  |  |  |  |  |  |  |  |
Derivative, Energy Notional Amount | MMBTU |  | 0.0 |  |  | 0.0 |  |  | 0.0 |
Natural Gas [Member] | Public Service Co Of Oklahoma [Member] |  |  |  |  |  |  |  |  |
Commodity: |  |  |  |  |  |  |  |  |
Derivative, Energy Notional Amount | MMBTU |  | 48.0 |  |  | 48.0 |  |  | 34.9 |
Natural Gas [Member] | Southwestern Electric Power Co [Member] |  |  |  |  |  |  |  |  |
Commodity: |  |  |  |  |  |  |  |  |
Derivative, Energy Notional Amount | MMBTU |  | 19.9 |  |  | 19.9 |  |  | 17.9 |
Heating Oil and Gasoline [Member] |  |  |  |  |  |  |  |  |
Commodity: |  |  |  |  |  |  |  |  |
Derivative, Volume Notional Amount | gal |  | 6.0 |  |  | 6.0 |  |  | 6.5 |
Heating Oil and Gasoline [Member] | AEP Texas Inc. [Member] |  |  |  |  |  |  |  |  |
Commodity: |  |  |  |  |  |  |  |  |
Derivative, Volume Notional Amount | gal |  | 1.5 |  |  | 1.5 |  |  | 1.8 |
Heating Oil and Gasoline [Member] | Appalachian Power Co [Member] |  |  |  |  |  |  |  |  |
Commodity: |  |  |  |  |  |  |  |  |
Derivative, Volume Notional Amount | gal |  | 0.8 |  |  | 0.8 |  |  | 1.0 |
Heating Oil and Gasoline [Member] | Indiana Michigan Power Co [Member] |  |  |  |  |  |  |  |  |
Commodity: |  |  |  |  |  |  |  |  |
Derivative, Volume Notional Amount | gal |  | 1.0 |  |  | 1.0 |  |  | 0.6 |
Heating Oil and Gasoline [Member] | Ohio Power Co [Member] |  |  |  |  |  |  |  |  |
Commodity: |  |  |  |  |  |  |  |  |
Derivative, Volume Notional Amount | gal |  | 1.0 |  |  | 1.0 |  |  | 1.2 |
Heating Oil and Gasoline [Member] | Public Service Co Of Oklahoma [Member] |  |  |  |  |  |  |  |  |
Commodity: |  |  |  |  |  |  |  |  |
Derivative, Volume Notional Amount | gal |  | 0.6 |  |  | 0.6 |  |  | 0.7 |
Heating Oil and Gasoline [Member] | Southwestern Electric Power Co [Member] |  |  |  |  |  |  |  |  |
Commodity: |  |  |  |  |  |  |  |  |
Derivative, Volume Notional Amount | gal |  | 0.7 |  |  | 0.7 |  |  | 0.9 |
Interest Rate Contract [Member] |  |  |  |  |  |  |  |  |
Commodity: |  |  |  |  |  |  |  |  |
Derivative, Notional Amount |  | $ 69,600,000 |  |  | $ 69,600,000 |  |  | $ 80,100,000 |
Interest Rate Contract [Member] | AEP Texas Inc. [Member] |  |  |  |  |  |  |  |  |
Commodity: |  |  |  |  |  |  |  |  |
Derivative, Notional Amount |  | 0 |  |  | 0 |  |  | 0 |
Interest Rate Contract [Member] | Appalachian Power Co [Member] |  |  |  |  |  |  |  |  |
Commodity: |  |  |  |  |  |  |  |  |
Derivative, Notional Amount |  | 0 |  |  | 0 |  |  | 0 |
Interest Rate Contract [Member] | Indiana Michigan Power Co [Member] |  |  |  |  |  |  |  |  |
Commodity: |  |  |  |  |  |  |  |  |
Derivative, Notional Amount |  | 0 |  |  | 0 |  |  | 0 |
Interest Rate Contract [Member] | Ohio Power Co [Member] |  |  |  |  |  |  |  |  |
Commodity: |  |  |  |  |  |  |  |  |
Derivative, Notional Amount |  | 0 |  |  | 0 |  |  | 0 |
Interest Rate Contract [Member] | Public Service Co Of Oklahoma [Member] |  |  |  |  |  |  |  |  |
Commodity: |  |  |  |  |  |  |  |  |
Derivative, Notional Amount |  | 0 |  |  | 0 |  |  | 0 |
Interest Rate Contract [Member] | Southwestern Electric Power Co [Member] |  |  |  |  |  |  |  |  |
Commodity: |  |  |  |  |  |  |  |  |
Derivative, Notional Amount |  | 0 |  |  | 0 |  |  | $ 0 |
Vertically Integrated Utilities Revenues [Member] |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  | 4,300,000 |  | 17,000,000.0 | (21,400,000) |  | 11,700,000 |  |
Vertically Integrated Utilities Revenues [Member] | AEP Texas Inc. [Member] |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  | 0 |  | 0 | 0 |  | 0 |  |
Vertically Integrated Utilities Revenues [Member] | Appalachian Power Co [Member] |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  | 0 |  | 0 | 0 |  | 0 |  |
Vertically Integrated Utilities Revenues [Member] | Indiana Michigan Power Co [Member] |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  | 0 |  | 0 | 0 |  | 0 |  |
Vertically Integrated Utilities Revenues [Member] | Ohio Power Co [Member] |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  | 0 |  | 0 | 0 |  | 0 |  |
Vertically Integrated Utilities Revenues [Member] | Public Service Co Of Oklahoma [Member] |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  | 0 |  | 0 | 0 |  | 0 |  |
Vertically Integrated Utilities Revenues [Member] | Southwestern Electric Power Co [Member] |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  | 0 |  | 0 | 0 |  | 0 |  |
Generation and Marketing Revenues [Member] |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  | (53,000,000.0) |  | (141,800,000) | (97,700,000) |  | (289,200,000) |  |
Generation and Marketing Revenues [Member] | AEP Texas Inc. [Member] |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  | 0 |  | 0 | 0 |  | 0 |  |
Generation and Marketing Revenues [Member] | Appalachian Power Co [Member] |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  | 0 |  | 0 | 0 |  | 0 |  |
Generation and Marketing Revenues [Member] | Indiana Michigan Power Co [Member] |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  | 0 |  | 0 | 0 |  | 0 |  |
Generation and Marketing Revenues [Member] | Ohio Power Co [Member] |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  | 0 |  | 0 | 0 |  | 0 |  |
Generation and Marketing Revenues [Member] | Public Service Co Of Oklahoma [Member] |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  | 0 |  | 0 | 0 |  | 0 |  |
Generation and Marketing Revenues [Member] | Southwestern Electric Power Co [Member] |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  | 0 |  | 0 | 0 |  | 0 |  |
Electric Generation, Transmission and Distribution Revenues [Member] |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  | 0 |  | 0 | 0 |  | 0 |  |
Electric Generation, Transmission and Distribution Revenues [Member] | AEP Texas Inc. [Member] |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  | 0 |  | 0 | 0 |  | 0 |  |
Electric Generation, Transmission and Distribution Revenues [Member] | Appalachian Power Co [Member] |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  | 0 |  | 0 | 100,000 |  | 0 |  |
Electric Generation, Transmission and Distribution Revenues [Member] | Indiana Michigan Power Co [Member] |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  | 4,300,000 |  | 17,000,000.0 | (21,500,000) |  | 11,700,000 |  |
Electric Generation, Transmission and Distribution Revenues [Member] | Ohio Power Co [Member] |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  | 0 |  | 0 | 0 |  | 0 |  |
Electric Generation, Transmission and Distribution Revenues [Member] | Public Service Co Of Oklahoma [Member] |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  | 0 |  | 0 | 0 |  | 0 |  |
Electric Generation, Transmission and Distribution Revenues [Member] | Southwestern Electric Power Co [Member] |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  | 0 |  | 0 | 0 |  | 0 |  |
Purchased Electricity, Fuel and Other Consumables Used for Electric Generation [Member] |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  | 700,000 |  | 1,300,000 | 1,700,000 |  | 2,000,000.0 |  |
Purchased Electricity, Fuel and Other Consumables Used for Electric Generation [Member] | AEP Texas Inc. [Member] |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  | 0 |  | 0 | 0 |  | 0 |  |
Purchased Electricity, Fuel and Other Consumables Used for Electric Generation [Member] | Appalachian Power Co [Member] |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  | 700,000 |  | 1,300,000 | 1,600,000 |  | 1,900,000 |  |
Purchased Electricity, Fuel and Other Consumables Used for Electric Generation [Member] | Indiana Michigan Power Co [Member] |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  | 100,000 |  | 100,000 | 100,000 |  | 100,000 |  |
Purchased Electricity, Fuel and Other Consumables Used for Electric Generation [Member] | Ohio Power Co [Member] |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  | 0 |  | 0 | 0 |  | 0 |  |
Purchased Electricity, Fuel and Other Consumables Used for Electric Generation [Member] | Public Service Co Of Oklahoma [Member] |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  | 0 |  | 0 | 0 |  | 0 |  |
Purchased Electricity, Fuel and Other Consumables Used for Electric Generation [Member] | Southwestern Electric Power Co [Member] |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  | 0 |  | 0 | 0 |  | 0 |  |
Other Operation Expense [Member] |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  | 300,000 |  | (100,000) | 300,000 |  | (100,000) |  |
Other Operation Expense [Member] | AEP Texas Inc. [Member] |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  | 100,000 |  | 0 | 100,000 |  | 0 |  |
Other Operation Expense [Member] | Appalachian Power Co [Member] |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  | 0 |  | 0 | 0 |  | 0 |  |
Other Operation Expense [Member] | Indiana Michigan Power Co [Member] |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  | 100,000 |  | 0 | 100,000 |  | 0 |  |
Other Operation Expense [Member] | Ohio Power Co [Member] |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  | 0 |  | 0 | 0 |  | 0 |  |
Other Operation Expense [Member] | Public Service Co Of Oklahoma [Member] |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  | 0 |  | 0 | 0 |  | 0 |  |
Other Operation Expense [Member] | Southwestern Electric Power Co [Member] |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  | 0 |  | 0 | 0 |  | 0 |  |
Maintenance Expense [Member] |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  | 500,000 |  | (300,000) | 600,000 |  | (200,000) |  |
Maintenance Expense [Member] | AEP Texas Inc. [Member] |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  | 100,000 |  | (100,000) | 100,000 |  | (100,000) |  |
Maintenance Expense [Member] | Appalachian Power Co [Member] |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  | 100,000 |  | 0 | 100,000 |  | 0 |  |
Maintenance Expense [Member] | Indiana Michigan Power Co [Member] |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  | 100,000 |  | 0 | 100,000 |  | 0 |  |
Maintenance Expense [Member] | Ohio Power Co [Member] |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  | 100,000 |  | 0 | 100,000 |  | 0 |  |
Maintenance Expense [Member] | Public Service Co Of Oklahoma [Member] |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  | 0 |  | 0 | 0 |  | 0 |  |
Maintenance Expense [Member] | Southwestern Electric Power Co [Member] |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  | 100,000 |  | 0 | 100,000 |  | 0 |  |
Regulatory Assets [Member] |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts | [7] | 31,700,000 |  | (12,400,000) | 45,200,000 |  | (37,200,000) |  |
Regulatory Assets [Member] | AEP Texas Inc. [Member] |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts | [7] | 100,000 |  | (100,000) | 300,000 |  | (500,000) |  |
Regulatory Assets [Member] | Appalachian Power Co [Member] |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts | [7] | 15,200,000 |  | 5,900,000 | 15,100,000 |  | (1,200,000) |  |
Regulatory Assets [Member] | Indiana Michigan Power Co [Member] |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts | [7] | 4,600,000 |  | (1,600,000) | 3,000,000.0 |  | (2,100,000) |  |
Regulatory Assets [Member] | Ohio Power Co [Member] |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts | [7] | (3,100,000) |  | (12,800,000) | 5,500,000 |  | (25,100,000) |  |
Regulatory Assets [Member] | Public Service Co Of Oklahoma [Member] |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts | [7] | 8,900,000 |  | (2,300,000) | 7,700,000 |  | (3,500,000) |  |
Regulatory Assets [Member] | Southwestern Electric Power Co [Member] |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts | [7] | 200,000 |  | (900,000) | 5,100,000 |  | (2,400,000) |  |
Regulatory Liabilities [Member] |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts | [7] | 92,500,000 |  | 102,000,000.0 | 145,200,000 |  | 100,500,000 |  |
Regulatory Liabilities [Member] | AEP Texas Inc. [Member] |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts | [7] | (200,000) |  | 0 | 0 |  | 0 |  |
Regulatory Liabilities [Member] | Appalachian Power Co [Member] |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts | [7] | 12,600,000 |  | 17,400,000 | 25,700,000 |  | (8,800,000) |  |
Regulatory Liabilities [Member] | Indiana Michigan Power Co [Member] |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts | [7] | 7,100,000 |  | 3,600,000 | 9,300,000 |  | 4,800,000 |  |
Regulatory Liabilities [Member] | Ohio Power Co [Member] |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts | [7] | 0 |  | 0 | 0 |  | 0 |  |
Regulatory Liabilities [Member] | Public Service Co Of Oklahoma [Member] |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts | [7] | 33,800,000 |  | 42,400,000 | 52,100,000 |  | 60,400,000 |  |
Regulatory Liabilities [Member] | Southwestern Electric Power Co [Member] |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts |  |  |  |  |  |  |  |  |
Amount of Gain (Loss) Recognized on Risk Management Contracts | [7] | $ 34,600,000 |  | $ 33,600,000 | $ 49,600,000 |  | $ 45,500,000 |  |
[1] | Amounts include $(26) million and $(30) million as of June 30, 2024 and December 31, 2023, respectively, for the fair value hedge adjustment of hedged debt obligations for which hedge accounting has been discontinued.
[2] | Amounts included within Noncurrent Liabilities line item Long-term Debt on the Balance Sheet.
[3] | Gain (Loss) is included in Interest Expense on the statements of income.
[4] | The June 30, 2024 maturities of the net fair value of risk management contracts prior to cash collateral, assets/(liabilities), were as follows: Level 1 matures $(3) million in 2024 and $(4) million in periods 2025-2027; Level 2 matures $(22) million in 2024, $24 million in periods 2025-2027 and $6 million in periods 2028-2029; Level 3 matures $116 million in 2024, $142 million in periods 2025-2027, $22 million in periods 2028-2029 and $(12) million in periods 2030-2032. Risk management commodity contracts are substantially comprised of power contracts.
[5] | Amounts in “Other’’ column primarily represent counterparty netting of risk management and hedging contracts and associated cash collateral under the accounting guidance for “Derivatives and Hedging.’’
[6] | The December 31, 2023 maturities of the net fair value of risk management contracts prior to cash collateral, assets/(liabilities), were as follows: Level 1 matures $(11) million in 2024 and $(4) million in 2025-2027; Level 2 matures $(99) million in 2024, $(44) million in periods 2025-2027, $7 million in periods 2028-2029 and $2 million in periods 2030-2033; Level 3 matures $74 million in 2024, $43 million in periods 2025-2027, $18 million in periods 2028-2029 and $(16) million in periods 2030-2033. Risk management commodity contracts are substantially comprised of power contracts
[7] | Represents realized and unrealized gains and losses subject to regulatory accounting treatment recorded as either current or noncurrent on the balance sheets.

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- Definition Nominal or face amount used to calculate payment on derivative. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1B -Publisher FASB -URI https://asc.fasb.org//1943274/2147480434/815-10-50-1B Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1A -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480434/815-10-50-1A + Details
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- Definition Amount of cumulative increase (decrease) in fair value of hedged liability in fair value hedge, attributable to hedged risk, remaining after discontinued hedge. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4EE -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480434/815-10-50-4EE + Details
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