Acquisitions and Dispositions (Details) - USD ($)		9 Months Ended
		Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Customers		$ 963,600,000		$ 1,029,900,000
Net Property, Plant and Equipment		80,073,800,000		76,693,400,000
Accounts Payable, Current		2,265,600,000		2,032,500,000
Deferred Income Tax Liabilities, Net		9,958,800,000		9,415,700,000
Asset Retirement Obligation	[1],[2],[3],[4],[5],[6]	3,777,000,000		3,031,200,000
Proceeds from Sale of Assets		365,000,000.0	$ 1,335,600,000
Proceeds from Sale of Equity Method Investments		114,000,000.0	0
Generation & Marketing | New Mexico Renewable Development
Proceeds from Sale of Equity Method Investments		107,000,000
Generation & Marketing | Competitive Contracted Renewables
Proceeds from Sale of Productive Assets			1,200,000,000
Gain (Loss) on Disposition of Business			112,000,000
gain (loss) on Disposition of Business net of Tax			88,000,000
Public Service Co Of Oklahoma [Member]
Customers		59,500,000		107,600,000
Net Property, Plant and Equipment		6,382,800,000		6,112,300,000
Accounts Payable, Current		181,100,000		159,300,000
Deferred Income Tax Liabilities, Net		888,600,000		831,200,000
Asset Retirement Obligation	[1],[3],[4]	120,900,000		84,200,000
Public Service Co Of Oklahoma [Member] | Vertically Integrated Utilities [Member] | Rock Falls Wind Facility
Payments to Acquire Property, Plant, and Equipment			$ 146,000,000
Southwestern Electric Power Co [Member]
Customers		27,500,000		39,000,000.0
Net Property, Plant and Equipment		8,908,200,000		8,558,400,000
Accounts Payable, Current		226,200,000		198,900,000
Deferred Income Tax Liabilities, Net		1,260,400,000		1,179,300,000
Asset Retirement Obligation	[1],[2],[3],[4]	281,900,000		281,600,000
AEP Transmission Co [Member]
Customers		61,200,000		82,200,000
Net Property, Plant and Equipment		15,399,600,000		14,497,700,000
Accounts Payable, Current		322,500,000		274,700,000
Deferred Income Tax Liabilities, Net		1,236,900,000		$ 1,147,700,000
AEP OnSite Partners | Generation & Marketing
Proceeds from Divestiture of Businesses		$ 318,000,000

[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.