Commitments, Guarantees and Contingencies (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Maximum Potential Loss [Abstract]
Max Potential Loss on Master Lease Agreements		$ 42,800		$ 42,800
Commitments, Guarantees and Contingencies (Textuals) [Abstract]
HB6 Settlement Payment				450
Asset Retirement Obligation	[1],[2],[3],[4],[5],[6]	3,777,000		3,777,000		$ 3,031,200
Property, Plant and Equipment		24,504,500		24,504,500		24,329,500
Regulatory Assets, Noncurrent		5,318,900		5,318,900		5,092,400
Utilities Operating Expense, Operations		805,800	$ 719,900	2,385,400	$ 2,031,100
SEC Matter Loss Contingency				19,000
Revised CCR Rule [Member]
Commitments, Guarantees and Contingencies (Textuals) [Abstract]
Asset Retirement Obligation		674,400		674,400
Property, Plant and Equipment	[7]	176,900		176,900
Regulatory Assets, Noncurrent	[8]	355,000		355,000
Utilities Operating Expense, Operations	[9]			142,500
Non-Registrants [Member] | Revised CCR Rule [Member]
Commitments, Guarantees and Contingencies (Textuals) [Abstract]
Asset Retirement Obligation		166,100		166,100
Property, Plant and Equipment	[7]	43,800		43,800
Regulatory Assets, Noncurrent	[8]	46,100		46,100
Utilities Operating Expense, Operations	[9]			76,200
AEP Texas Inc. [Member]
Maximum Potential Loss [Abstract]
Max Potential Loss on Master Lease Agreements		9,900		9,900
Commitments, Guarantees and Contingencies (Textuals) [Abstract]
Asset Retirement Obligation	[3],[4]	3,900		3,900		4,500
Regulatory Assets, Noncurrent		354,000		354,000		315,300
Utilities Operating Expense, Operations		164,700	154,400	453,300	395,200
AEP Transmission Co [Member]
Commitments, Guarantees and Contingencies (Textuals) [Abstract]
Regulatory Assets, Noncurrent		900		900		3,100
Utilities Operating Expense, Operations		31,700	31,600	101,600	87,000
Appalachian Power Co [Member]
Maximum Potential Loss [Abstract]
Max Potential Loss on Master Lease Agreements		5,500		5,500
Commitments, Guarantees and Contingencies (Textuals) [Abstract]
Asset Retirement Obligation	[3],[4]	811,700		811,700		464,000
Property, Plant and Equipment		7,245,900		7,245,900		7,041,300
Regulatory Assets, Noncurrent		1,312,400		1,312,400		1,155,100
Utilities Operating Expense, Operations		204,200	187,900	628,800	569,600
Appalachian Power Co [Member] | Revised CCR Rule [Member]
Commitments, Guarantees and Contingencies (Textuals) [Abstract]
Asset Retirement Obligation		312,200		312,200
Property, Plant and Equipment	[7]	75,600		75,600
Regulatory Assets, Noncurrent	[8]	236,600		236,600
Utilities Operating Expense, Operations				0
Indiana Michigan Power Co [Member]
Maximum Potential Loss [Abstract]
Max Potential Loss on Master Lease Agreements		4,000		4,000
Commitments, Guarantees and Contingencies (Textuals) [Abstract]
Asset Retirement Obligation	[3],[4],[5]	2,248,900		2,248,900		2,106,000
Property, Plant and Equipment		5,675,800		5,675,800		5,646,800
Regulatory Assets, Noncurrent		572,600		572,600		406,300
Utilities Operating Expense, Operations		180,000	168,900	548,500	508,700
Indiana Michigan Power Co [Member] | Revised CCR Rule [Member]
Commitments, Guarantees and Contingencies (Textuals) [Abstract]
Asset Retirement Obligation		85,700		85,700
Property, Plant and Equipment		0		0
Regulatory Assets, Noncurrent	[8]	72,300		72,300
Utilities Operating Expense, Operations	[9]			13,400
Ohio Power Co [Member]
Maximum Potential Loss [Abstract]
Max Potential Loss on Master Lease Agreements		6,900		6,900
Commitments, Guarantees and Contingencies (Textuals) [Abstract]
Asset Retirement Obligation	[3],[4]	55,500		55,500		2,100
Regulatory Assets, Noncurrent		394,900		394,900		455,000
Utilities Operating Expense, Operations		343,200	296,900	920,200	836,100
Ohio Power Co [Member] | Revised CCR Rule [Member]
Commitments, Guarantees and Contingencies (Textuals) [Abstract]
Asset Retirement Obligation		52,900		52,900
Property, Plant and Equipment		0		0
Regulatory Assets, Noncurrent		0		0
Utilities Operating Expense, Operations	[9]			52,900
Public Service Co Of Oklahoma [Member]
Maximum Potential Loss [Abstract]
Max Potential Loss on Master Lease Agreements		4,100		4,100
Commitments, Guarantees and Contingencies (Textuals) [Abstract]
Asset Retirement Obligation	[1],[3],[4]	120,900		120,900		84,200
Property, Plant and Equipment		2,760,200		2,760,200		2,695,500
Regulatory Assets, Noncurrent		524,900		524,900		522,700
Utilities Operating Expense, Operations		112,200	103,900	328,100	283,500
Public Service Co Of Oklahoma [Member] | Revised CCR Rule [Member]
Commitments, Guarantees and Contingencies (Textuals) [Abstract]
Asset Retirement Obligation		33,700		33,700
Property, Plant and Equipment	[7]	33,700		33,700
Regulatory Assets, Noncurrent		0		0
Utilities Operating Expense, Operations				0
Southwestern Electric Power Co [Member]
Maximum Potential Loss [Abstract]
Max Potential Loss on Master Lease Agreements		4,900		4,900
Commitments, Guarantees and Contingencies (Textuals) [Abstract]
Asset Retirement Obligation	[1],[2],[3],[4]	281,900		281,900		281,600
Property, Plant and Equipment		4,845,100		4,845,100		4,790,700
Regulatory Assets, Noncurrent		1,120,300		1,120,300		$ 1,131,800
Utilities Operating Expense, Operations		95,100	$ 96,900	324,300	$ 281,300
Southwestern Electric Power Co [Member] | Revised CCR Rule [Member]
Commitments, Guarantees and Contingencies (Textuals) [Abstract]
Asset Retirement Obligation		23,800		23,800
Property, Plant and Equipment	[7]	23,800		23,800
Regulatory Assets, Noncurrent		0		0
Utilities Operating Expense, Operations				0
Letters of Credit [Member]
Maximum Future Payments for Letters of Credit [Abstract]
Maximum Future Payments for Letters of Credit Issued Under the Uncommitted Facility		236,300		236,300
Commitments, Guarantees and Contingencies (Textuals) [Abstract]
Letters of Credit Limit		1,200,000		1,200,000
Uncommitted Facility		450,000		450,000
Letters of Credit [Member] | AEP Texas Inc. [Member]
Maximum Future Payments for Letters of Credit [Abstract]
Maximum Future Payments for Letters of Credit Issued Under the Uncommitted Facility		1,800		1,800
March 2029 [Member] | Letters of Credit [Member]
Commitments, Guarantees and Contingencies (Textuals) [Abstract]
Revolving Credit Facilities		5,000,000		5,000,000
March 2027 [Member] | Letters of Credit [Member]
Commitments, Guarantees and Contingencies (Textuals) [Abstract]
Prior Revolving Credit Facilities		4,000,000		4,000,000
Revolving Credit Facilities		$ 1,000,000		$ 1,000,000

[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.

[7] ARO is related to a legacy CCR surface impoundment or CCR management unit at an operating generation facility.

[8] ARO is related to a legacy CCR surface impoundment or CCR management unit at a retired generation facility and recognition of a regulatory asset in accordance with the accounting guidance for “Regulated Operations” is supported.

[9] ARO is related to a legacy CCR surface impoundment or CCR management unit and recognition of a regulatory asset in accordance with the accounting guidance for “Regulated Operations” is not yet supported.