Acquisitions, Dispositions and Impairments (Details)		3 Months Ended		12 Months Ended
		Sep. 30, 2022 USD ($)	Jun. 30, 2022 USD ($)	Dec. 31, 2023 USD ($) MW	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Mar. 31, 2023 USD ($)
Asset Impairments and Other Related Charges				$ 85,600,000	$ 48,800,000	$ 11,600,000
Utilities Operating Expense, Operations				2,810,500,000	2,878,100,000	2,547,700,000
Additional Paid in Capital				9,073,900,000	8,051,000,000
Asset Retirement Obligation, Liabilities Settled	[1],[2],[3],[4],[5],[6]			130,600,000	47,000,000.0
Property, Plant and Equipment, Generation				24,329,500,000	25,834,200,000
Obligations Under Operating Leases				519,400,000	552,500,000
Customers				1,029,900,000	1,145,100,000
Materials and Supplies				1,025,800,000	915,100,000
Net Investment				76,693,400,000	73,339,100,000
Noncurrent Regulatory Assets				5,092,400,000	4,762,000,000
Accounts Payable - Affiliated Companies for collected reclamation costs that have been billed to SWEPCo				2,032,500,000	2,670,800,000
Long-term Debt, Current Maturities				2,490,500,000	2,486,400,000
Customer Deposits, Current				423,700,000	408,800,000
Regulatory Liabilities and Deferred Investment Tax Credits				8,182,400,000	8,115,600,000
Long-term Debt, Excluding Current Maturities				37,652,700,000	34,314,600,000
Property, Plant and Equipment, Other				6,484,900,000	5,971,800,000
Depreciation and Amortization of Property, Plant and Equipment				2,927,500,000	3,072,800,000	2,717,100,000
Equity Method Investment, Other than Temporary Impairment				$ 19,000,000.0	188,000,000.0	0
Equity Method Investment, Ownership Percentage				50.00%
Deferred Tax Assets				$ 3,216,100,000	3,567,400,000
Disposal Group, Including Discontinued Operation, Income Statement Disclosures
Proceeds from Sale of Property, Plant, and Equipment				(1,341,400,000)	(218,000,000.0)	118,900,000
Kentucky Operations [Member]
Asset Impairments and Other Related Charges				0	363,300,000	0
Vertically Integrated Utilities [Member]
Asset Impairments and Other Related Charges				85,600,000	24,900,000	11,600,000
Disposal Group, Including Discontinued Operation, Income Statement Disclosures
Enterprise Value					2,850,000,000
Pretax Reduction in Investment Basis				$ 335,000,000
Business Acquisition, Transaction Costs							$ 28,000,000
Vertically Integrated Utilities [Member] | Proceeds for KY Operations
Disposal Group, Including Discontinued Operation, Income Statement Disclosures
Enterprise Value					2,646,000,000
Vertically Integrated Utilities [Member] | Sundance [Member]
WindGenerationMWs | MW				199
Vertically Integrated Utilities [Member] | Maverick [Member]
WindGenerationMWs | MW				287
Vertically Integrated Utilities [Member] | Traverse [Member]
WindGenerationMWs | MW				998
Vertically Integrated Utilities [Member] | North Central Wind Energy Facilities | Maverick [Member]
Payments to Acquire Property, Plant, and Equipment						383,000,000
Vertically Integrated Utilities [Member] | North Central Wind Energy Facilities | Traverse [Member]
Payments to Acquire Property, Plant, and Equipment					1,200,000,000
Generation and Marketing [Member]
Asset Impairments and Other Related Charges				$ 0	0	0
Generation and Marketing [Member] | BP Wind Energy [Member]
Equity Method Investment, Other than Temporary Impairment		$ 2,000,000	$ 186,000,000
Equity Method Investment, Ownership Percentage				50.00%
Generation and Marketing [Member] | New Mexico Renewable Development [Member]
Equity Method Investment, Other than Temporary Impairment				$ 19,000,000
Generation and Marketing [Member] | Proceeds of Mineral Rights Sale
Disposal Group, Including Discontinued Operation, Income Statement Disclosures
Proceeds from Sale of Property, Plant, and Equipment					120,000,000
Gain (Loss) on Disposition of Other Assets					116,000,000
Generation and Marketing [Member] | Dry Lake Solar Project [Member]
Payments to Acquire Property, Plant, and Equipment						114,000,000
Transmission and Distribution Companies [Member]
Asset Impairments and Other Related Charges				0	0	0
AEP Transmission Holdco
Asset Impairments and Other Related Charges				0	0	0
Disposal Group, Including Discontinued Operation, Income Statement Disclosures
Enterprise Value					2,850,000,000
Pretax Reduction in Investment Basis				335,000,000
AEP Transmission Holdco | Proceeds for KY Operations
Disposal Group, Including Discontinued Operation, Income Statement Disclosures
Enterprise Value					2,646,000,000
AEP Texas Inc. [Member]
Utilities Operating Expense, Operations				541,600,000	594,200,000	489,500,000
Additional Paid in Capital				2,079,600,000	1,558,200,000
Asset Retirement Obligation, Liabilities Settled	[3],[4]			300,000	200,000
Obligations Under Operating Leases				50,900,000	67,800,000
Customers				176,500,000	150,900,000
Materials and Supplies				190,400,000	138,800,000
Net Investment				12,774,000,000	11,681,600,000
Noncurrent Regulatory Assets				315,300,000	298,300,000
Accounts Payable - Affiliated Companies for collected reclamation costs that have been billed to SWEPCo				192,300,000	331,000,000.0
Long-term Debt, Current Maturities				96,000,000.0	278,500,000
Regulatory Liabilities and Deferred Investment Tax Credits				1,261,400,000	1,259,600,000
Long-term Debt, Excluding Current Maturities				5,793,800,000	5,379,300,000
Property, Plant and Equipment, Other				1,145,900,000	1,022,800,000
Depreciation and Amortization of Property, Plant and Equipment				380,000,000.0	363,500,000	327,200,000
Deferred Tax Assets				173,600,000	177,000,000.0
AEP Transmission Co [Member]
Utilities Operating Expense, Operations				109,000,000.0	136,300,000	105,500,000
Payments to Acquire Property, Plant, and Equipment				6,900,000	9,800,000	17,900,000
Obligations Under Operating Leases				1,400,000	1,500,000
Customers				82,200,000	46,900,000
Materials and Supplies				0	10,700,000
Net Investment				14,497,700,000	13,339,900,000
Noncurrent Regulatory Assets				3,100,000	7,200,000
Accounts Payable - Affiliated Companies for collected reclamation costs that have been billed to SWEPCo				274,700,000	427,800,000
Long-term Debt, Current Maturities				95,000,000.0	60,000,000.0
Regulatory Liabilities and Deferred Investment Tax Credits				783,700,000	723,300,000
Long-term Debt, Excluding Current Maturities				5,319,400,000	4,722,800,000
Property, Plant and Equipment, Other				501,400,000	476,800,000
Depreciation and Amortization of Property, Plant and Equipment				393,800,000	346,200,000	297,300,000
Deferred Tax Assets				188,100,000	165,000,000.0
Appalachian Power Co [Member]
Asset Impairments and Other Related Charges				0	24,900,000	0
Utilities Operating Expense, Operations				748,400,000	724,100,000	610,000,000.0
Additional Paid in Capital				1,834,500,000	1,828,700,000
Asset Retirement Obligation, Liabilities Settled	[3],[4]			23,100,000	12,700,000
Property, Plant and Equipment, Generation				7,041,300,000	6,776,800,000
Obligations Under Operating Leases				59,800,000	59,100,000
Customers				170,300,000	168,900,000
Materials and Supplies				148,400,000	130,600,000
Net Investment				12,931,500,000	12,379,200,000
Noncurrent Regulatory Assets				1,155,100,000	1,058,600,000
Accounts Payable - Affiliated Companies for collected reclamation costs that have been billed to SWEPCo				280,400,000	451,200,000
Long-term Debt, Current Maturities				538,800,000	251,800,000
Customer Deposits, Current				80,000,000.0	75,100,000
Regulatory Liabilities and Deferred Investment Tax Credits				1,081,900,000	1,143,600,000
Long-term Debt, Excluding Current Maturities				5,049,500,000	5,158,700,000
Property, Plant and Equipment, Other				981,300,000	883,300,000
Depreciation and Amortization of Property, Plant and Equipment				571,100,000	576,100,000	547,000,000.0
Deferred Tax Assets				473,000,000.0	510,300,000
Indiana Michigan Power Co [Member]
Utilities Operating Expense, Operations				662,800,000	621,000,000.0	645,200,000
Additional Paid in Capital				997,600,000	988,800,000
Asset Retirement Obligation, Liabilities Settled	[3],[4],[5]			3,700,000	600,000
Property, Plant and Equipment, Generation				5,646,800,000	5,585,100,000
Obligations Under Operating Leases				37,700,000	48,900,000
Customers				66,900,000	96,600,000
Materials and Supplies				208,200,000	188,100,000
Net Investment				7,629,000,000	7,411,500,000
Noncurrent Regulatory Assets				406,300,000	459,600,000
Accounts Payable - Affiliated Companies for collected reclamation costs that have been billed to SWEPCo				225,800,000	173,400,000
Long-term Debt, Current Maturities				83,700,000	341,800,000
Customer Deposits, Current				72,200,000	48,600,000
Regulatory Liabilities and Deferred Investment Tax Credits				2,052,300,000	1,702,200,000
Long-term Debt, Excluding Current Maturities				3,415,700,000	2,919,000,000
Property, Plant and Equipment, Other				898,500,000	839,300,000
Depreciation and Amortization of Property, Plant and Equipment				439,800,000	511,900,000	424,900,000
Deferred Tax Assets				1,014,100,000	933,700,000
Ohio Power Co [Member]
Cost of Purchased Power from Affiliate				86,800,000	9,800,000	51,900,000
Utilities Operating Expense, Operations				1,091,700,000	982,000,000.0	836,800,000
Additional Paid in Capital				1,012,800,000	837,800,000
Asset Retirement Obligation, Liabilities Settled	[4]			3,100,000	100,000
Obligations Under Operating Leases				56,700,000	60,300,000
Customers				39,200,000	119,900,000
Materials and Supplies				175,000,000.0	109,500,000
Net Investment				9,299,900,000	8,609,300,000
Noncurrent Regulatory Assets				455,000,000.0	327,300,000
Accounts Payable - Affiliated Companies for collected reclamation costs that have been billed to SWEPCo				320,700,000	337,300,000
Long-term Debt, Current Maturities				0	100,000
Customer Deposits, Current				62,000,000.0	96,500,000
Regulatory Liabilities and Deferred Investment Tax Credits				1,003,600,000	1,044,000,000
Long-term Debt, Excluding Current Maturities				3,366,800,000	2,970,200,000
Property, Plant and Equipment, Other				1,125,000,000	1,051,400,000
Depreciation and Amortization of Property, Plant and Equipment				315,800,000	293,100,000	301,100,000
Deferred Tax Assets				271,400,000	218,800,000
Public Service Co Of Oklahoma [Member]
Utilities Operating Expense, Operations				355,800,000	400,400,000	353,800,000
Additional Paid in Capital				1,039,300,000	1,042,600,000
Asset Retirement Obligation, Liabilities Settled	[1],[3],[4]			1,200,000	700,000
Property, Plant and Equipment, Generation				2,695,500,000	2,394,800,000
Obligations Under Operating Leases				106,800,000	99,300,000
Customers				107,600,000	70,100,000
Materials and Supplies				106,900,000	111,100,000
Net Investment				6,112,300,000	5,626,500,000
Noncurrent Regulatory Assets				522,700,000	653,700,000
Accounts Payable - Affiliated Companies for collected reclamation costs that have been billed to SWEPCo				159,300,000	202,900,000
Long-term Debt, Current Maturities				600,000	500,000
Customer Deposits, Current				81,400,000	59,000,000.0
Regulatory Liabilities and Deferred Investment Tax Credits				765,600,000	809,100,000
Long-term Debt, Excluding Current Maturities				2,384,000,000	1,912,300,000
Property, Plant and Equipment, Other				505,900,000	469,300,000
Depreciation and Amortization of Property, Plant and Equipment				240,300,000	226,200,000	185,900,000
Deferred Tax Assets				282,300,000	225,000,000.0
Southwestern Electric Power Co [Member]
Asset Impairments and Other Related Charges				85,600,000	0	11,600,000
Utilities Operating Expense, Operations				360,500,000	424,700,000	360,300,000
Additional Paid in Capital				1,492,200,000	1,442,200,000
Asset Retirement Obligation, Liabilities Settled	[1],[2],[3],[4]			55,000,000.0	25,800,000
Property, Plant and Equipment, Generation				4,790,700,000	5,476,200,000
Obligations Under Operating Leases				122,500,000	120,200,000
Customers				39,000,000.0	38,800,000
Materials and Supplies				88,400,000	92,100,000
Net Investment				8,558,400,000	8,262,200,000
Noncurrent Regulatory Assets				1,131,800,000	1,042,400,000
Accounts Payable - Affiliated Companies for collected reclamation costs that have been billed to SWEPCo				198,900,000	213,100,000
Long-term Debt, Current Maturities				0	6,200,000
Customer Deposits, Current				72,500,000	65,400,000
Regulatory Liabilities and Deferred Investment Tax Credits				756,100,000	825,700,000
Long-term Debt, Excluding Current Maturities				3,646,900,000	3,385,400,000
Property, Plant and Equipment, Other				814,400,000	804,400,000
Depreciation and Amortization of Property, Plant and Equipment				323,400,000	319,300,000	292,900,000
Deferred Tax Assets				441,500,000	374,900,000
Southwestern Electric Power Co [Member] | North Central Wind Energy Facilities
Payments to Acquire Property, Plant, and Equipment				0	658,000,000.0	355,800,000
Southwestern Electric Power Co [Member] | Vertically Integrated Utilities [Member] | Turk Generating Plant [Member]
Asset Impairments and Other Related Charges				86,000,000
Southwestern Electric Power Co [Member] | Vertically Integrated Utilities [Member] | Dolet Hills Power Station [Member]
Asset Impairments and Other Related Charges					12,000,000
AEP Wind Holdings LLC [Member] | Indiana Michigan Power Co [Member] | Generation and Marketing [Member]
Cost of Purchased Power from Affiliate				8,000,000.0	11,800,000	9,900,000
AEP Wind Holdings LLC [Member] | Ohio Power Co [Member] | Generation and Marketing [Member]
Cost of Purchased Power from Affiliate				16,100,000	23,600,000	19,600,000
AEP Wind Holdings LLC [Member] | Southwestern Electric Power Co [Member] | Generation and Marketing [Member]
Cost of Purchased Power from Affiliate				$ 0	13,700,000	14,500,000
Dry Lake Solar Project [Member]
Noncash or Part Noncash Acquisition, Other Assets Acquired						18,900,000
Dry Lake Solar Project [Member] | Noncontrolling Interests [Member]
Noncash or Part Noncash Acquisition, Other Assets Acquired						18,900,000
Dry Lake Solar Project [Member] | Generation and Marketing [Member]
Percentage of an Asset Acquired				75.00%
North Central Wind Energy Facilities | Vertically Integrated Utilities [Member]
WindGenerationMWs | MW				1,484
Payments to Acquire Property, Plant, and Equipment				$ 2,000,000,000
North Central Wind Energy Facilities | Vertically Integrated Utilities [Member] | Sundance [Member]
Payments to Acquire Property, Plant, and Equipment						270,000,000
North Central Wind Energy Facilities | Public Service Co Of Oklahoma [Member] | Vertically Integrated Utilities [Member]
Percentage of an Asset Acquired				45.50%
North Central Wind Energy Facilities | Southwestern Electric Power Co [Member] | Vertically Integrated Utilities [Member]
Percentage of an Asset Acquired				54.50%
Competitive Contracted Renewables | Generation and Marketing [Member]
Equity Method Investment, Ownership Percentage				50.00%
Disposal Group, Including Discontinued Operation, Income Statement Disclosures
Proceeds from Sales of Assets				$ 1,200,000,000
Gain (Loss) on Disposition of Business net of Tax				73,000,000
Gain (Loss) on Disposition of Business				93,000,000
Rock Falls [Member] | Public Service Co Of Oklahoma [Member] | Vertically Integrated Utilities [Member]
Payments to Acquire Property, Plant, and Equipment				146,000,000
Noncontrolling Interests [Member] | Dry Lake Solar Project [Member]
Noncash Contribution of Assets by Noncontrolling Interest				$ 0	$ 0	$ 35,300,000

[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 $2.11 billion and $2 billion as of December 31, 2023 and 2022, respectively.

[6] Includes ARO related to solar farms.