Property, Plant and Equipment (Details) - USD ($) $ in Millions		9 Months Ended
		Sep. 30, 2024	Dec. 31, 2023
Asset Retirement Obligations (ARO)
Beginning Balance	[1],[2],[3],[4],[5],[6]	$ 3,031.2
Accretion Expense	[1],[2],[3],[4],[5],[6]	97.2
Liabilities Incurred	[1],[2],[3],[4],[5],[6]	606.0
Liabilities Settled	[1],[2],[3],[4],[5],[6]	(80.3)
Asset Retirement Obligation, Revision of Estimate	[1],[2],[3],[4],[5],[6],[7]	122.9
Ending Balance	[1],[2],[3],[4],[5],[6]	3,777.0
CCR Rule Revision
Asset Retirement Obligations (ARO)
Liabilities Incurred		602.0
Asset Retirement Obligation, Revision of Estimate		72.0
AEP Texas Inc. [Member]
Asset Retirement Obligations (ARO)
Beginning Balance	[3],[4]	4.5
Accretion Expense	[3],[4]	0.2
Liabilities Incurred	[3],[4]	0.0
Liabilities Settled	[3],[4]	(0.8)
Asset Retirement Obligation, Revision of Estimate	[3],[4],[7]	0.0
Ending Balance	[3],[4]	3.9
Appalachian Power Co [Member]
Asset Retirement Obligations (ARO)
Beginning Balance	[3],[4]	464.0
Accretion Expense	[3],[4]	17.6
Liabilities Incurred	[3],[4]	247.1
Liabilities Settled	[3],[4]	(14.2)
Asset Retirement Obligation, Revision of Estimate	[3],[4],[7]	97.2
Ending Balance	[3],[4]	811.7
Indiana Michigan Power Co [Member]
Asset Retirement Obligations (ARO)
Beginning Balance	[3],[4],[5]	2,106.0
Accretion Expense	[3],[4],[5]	59.1
Liabilities Incurred	[3],[4],[5]	85.7
Liabilities Settled	[3],[4],[5]	(1.9)
Asset Retirement Obligation, Revision of Estimate	[3],[4],[5],[7]	0.0
Ending Balance	[3],[4],[5]	2,248.9
Public Service Co Of Oklahoma [Member]
Asset Retirement Obligations (ARO)
Beginning Balance	[1],[3],[4]	84.2
Accretion Expense	[1],[3],[4]	4.1
Liabilities Incurred	[1],[3],[4]	33.7
Liabilities Settled	[1],[3],[4]	(1.1)
Asset Retirement Obligation, Revision of Estimate	[1],[3],[4],[7]	0.0
Ending Balance	[1],[3],[4]	120.9
Southwestern Electric Power Co [Member]
Asset Retirement Obligations (ARO)
Beginning Balance	[1],[2],[3],[4]	281.6
Accretion Expense	[1],[2],[3],[4]	10.8
Liabilities Incurred	[1],[2],[3],[4]	23.8
Liabilities Settled	[1],[2],[3],[4]	(54.2)
Asset Retirement Obligation, Revision of Estimate	[1],[2],[3],[4],[7]	19.9
Ending Balance	[1],[2],[3],[4]	281.9
Ohio Power Co [Member]
Asset Retirement Obligations (ARO)
Beginning Balance	[3],[4]	2.1
Accretion Expense	[3],[4]	0.6
Liabilities Incurred	[3],[4]	52.9
Liabilities Settled	[3],[4]	(0.1)
Asset Retirement Obligation, Revision of Estimate	[3],[4],[7]	0.0
Ending Balance	[3],[4]	55.5
Cook plant | Indiana Michigan Power Co [Member]
Property, Plant and Equipment (Textuals)
Asset Retirement Obligations (ARO) Liability for Nuclear Decommissioning of the Cook Plant		$ 2,100.0	$ 2,100.0

[1] Includes ARO related to wind farms.

[2] Includes ARO related to Sabine and DHLC.

[3] Includes ARO related to ash disposal facilities.

[4] Includes ARO related to asbestos removal.

[5] Includes ARO related to nuclear decommissioning costs for the Cook Plant of $2.1 billion and $2.1 billion as of September 30, 2024 and December 31, 2023, respectively.

[6] Includes ARO related to solar farms.

[7] Unless discussed above, primarily related to ash ponds, landfills and mine reclamation, generally due to changes in estimated closure area, volumes and/or unit costs.