Commitments, Guarantees and Contingencies (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Contractual Commitments
Less than 1 year		$ 1,313.1
For 2-3 years		1,673.0
For 4-5 years		622.3
After 5 years		675.9
Total Contractual Commitments		4,284.3
Commitments, Guarantees and Contingencies (Textuals)
Revolving Credit Facilities		5,000.0
Disposal, Assessed Fees and Related Interest	[1]	$ 300.4	$ 285.6
Regulatory Assets Currently Not Earning Return [Member] | Unamortized Loss on Reacquired Debt [Member] | Regulatory Assets Approved for Recovery [Member]
Commitments, Guarantees and Contingencies (Textuals)
Remaining Recovery Period		25 years
Letters of Credit [Member]
Maximum Future Payments for Letters of Credit Under Uncommitted Facilities
Maximum Future Payments for Letters of Credit Issued Under the Uncommitted Facility		$ 257.0
Commitments, Guarantees and Contingencies (Textuals)
Letters of Credit Limit		1,200.0
Uncommitted Facility		450.0
Fuel Purchase Contracts [Member]
Contractual Commitments
Less than 1 year	[2]	1,126.7
For 2-3 years	[2]	1,260.7
For 4-5 years	[2]	313.5
After 5 years	[2]	256.1
Total Contractual Commitments	[2]	2,957.0
Energy and Capacity Purchase Contracts [Member]
Contractual Commitments
Less than 1 year		186.4
For 2-3 years		412.3
For 4-5 years		308.8
After 5 years		419.8
Total Contractual Commitments		1,327.3
AEP Texas Inc. [Member] | Letters of Credit [Member]
Maximum Future Payments for Letters of Credit Under Uncommitted Facilities
Maximum Future Payments for Letters of Credit Issued Under the Uncommitted Facility		1.8
Appalachian Power Co [Member]
Contractual Commitments
Less than 1 year		635.3
For 2-3 years		706.3
For 4-5 years		165.0
After 5 years		75.9
Total Contractual Commitments		$ 1,582.5
Appalachian Power Co [Member] | Regulatory Assets Currently Not Earning Return [Member] | Unamortized Loss on Reacquired Debt [Member] | Regulatory Assets Approved for Recovery [Member]
Commitments, Guarantees and Contingencies (Textuals)
Remaining Recovery Period		22 years
Appalachian Power Co [Member] | Letters of Credit [Member]
Maximum Future Payments for Letters of Credit Under Uncommitted Facilities
Maximum Future Payments for Letters of Credit Issued Under the Uncommitted Facility		$ 6.3
Appalachian Power Co [Member] | Fuel Purchase Contracts [Member]
Contractual Commitments
Less than 1 year	[2]	595.2
For 2-3 years	[2]	626.1
For 4-5 years	[2]	99.5
After 5 years	[2]	0.0
Total Contractual Commitments	[2]	1,320.8
Appalachian Power Co [Member] | Energy and Capacity Purchase Contracts [Member]
Contractual Commitments
Less than 1 year		40.1
For 2-3 years		80.2
For 4-5 years		65.5
After 5 years		75.9
Total Contractual Commitments		261.7
Indiana Michigan Power Co [Member]
Contractual Commitments
Less than 1 year		271.4
For 2-3 years		486.1
For 4-5 years		367.4
After 5 years		423.8
Total Contractual Commitments		1,548.7
Commitments, Guarantees and Contingencies (Textuals)
Disposal, Assessed Fees and Related Interest	[1]	$ 300.4	285.6
Indiana Michigan Power Co [Member] | Regulatory Assets Currently Not Earning Return [Member] | Unamortized Loss on Reacquired Debt [Member] | Regulatory Assets Approved for Recovery [Member]
Commitments, Guarantees and Contingencies (Textuals)
Remaining Recovery Period		25 years
Indiana Michigan Power Co [Member] | Letters of Credit [Member]
Maximum Future Payments for Letters of Credit Under Uncommitted Facilities
Maximum Future Payments for Letters of Credit Issued Under the Uncommitted Facility		$ 2.9
Indiana Michigan Power Co [Member] | Fuel Purchase Contracts [Member]
Contractual Commitments
Less than 1 year	[2]	144.4
For 2-3 years	[2]	232.3
For 4-5 years	[2]	130.8
After 5 years	[2]	241.6
Total Contractual Commitments	[2]	749.1
Indiana Michigan Power Co [Member] | Energy and Capacity Purchase Contracts [Member]
Contractual Commitments
Less than 1 year		127.0
For 2-3 years		253.8
For 4-5 years		236.6
After 5 years		182.2
Total Contractual Commitments		799.6
Ohio Power Co [Member] | Energy and Capacity Purchase Contracts [Member]
Contractual Commitments
Less than 1 year		33.4
For 2-3 years		66.6
For 4-5 years		66.3
After 5 years		102.6
Total Contractual Commitments		268.9
Public Service Co Of Oklahoma [Member]
Contractual Commitments
Less than 1 year		88.1
For 2-3 years		175.9
For 4-5 years		88.0
After 5 years		56.3
Total Contractual Commitments		408.3
Public Service Co Of Oklahoma [Member] | Fuel Purchase Contracts [Member]
Contractual Commitments
Less than 1 year	[2]	31.5
For 2-3 years	[2]	36.6
For 4-5 years	[2]	0.0
After 5 years	[2]	0.0
Total Contractual Commitments	[2]	68.1
Public Service Co Of Oklahoma [Member] | Energy and Capacity Purchase Contracts [Member]
Contractual Commitments
Less than 1 year		56.6
For 2-3 years		139.3
For 4-5 years		88.0
After 5 years		56.3
Total Contractual Commitments		340.2
Southwestern Electric Power Co [Member]
Contractual Commitments
Less than 1 year		125.6
For 2-3 years		74.3
For 4-5 years		2.2
After 5 years		0.0
Total Contractual Commitments		202.1
Southwestern Electric Power Co [Member] | Fuel Purchase Contracts [Member]
Contractual Commitments
Less than 1 year	[2]	109.2
For 2-3 years	[2]	48.1
For 4-5 years	[2]	0.0
After 5 years	[2]	0.0
Total Contractual Commitments	[2]	157.3
Southwestern Electric Power Co [Member] | Energy and Capacity Purchase Contracts [Member]
Contractual Commitments
Less than 1 year		16.4
For 2-3 years		26.2
For 4-5 years		2.2
After 5 years		0.0
Total Contractual Commitments		44.8
Decommissioning and Low Level Waste Accumulation Disposal [Member]
Commitments, Guarantees and Contingencies (Textuals)
Cost of Decommissioning and Disposal of Radioactive Waste		2,200.0
Additional Ongoing Costs for Post Decommissioning Storage of SNF		7.0
Subsequent Decommissioning of the Spent Fuel Storage Facility		33.0
Amount Recovered in Rates for Decommissioning Costs		2.0	2.0	$ 4.0
Decommissioning Trust Assets Amount		3,500.0	3,000.0
Decommissioning and Low Level Waste Accumulation Disposal [Member] | Indiana Michigan Power Co [Member]
Commitments, Guarantees and Contingencies (Textuals)
Cost of Decommissioning and Disposal of Radioactive Waste		2,200.0
Additional Ongoing Costs for Post Decommissioning Storage of SNF		7.0
Subsequent Decommissioning of the Spent Fuel Storage Facility		33.0
Amount Recovered in Rates for Decommissioning Costs		2.0	2.0	4.0
Decommissioning Trust Assets Amount		3,500.0	3,000.0
Spent Nuclear Fuel Disposal [Member]
Commitments, Guarantees and Contingencies (Textuals)
DOE SNF Disposal Fee		0.0
Disposal, Assessed Fees and Related Interest		300.0	286.0
Trust Fund Assets One Time Fee Obligation for Nuclear Fuel Disposition		348.0	330.0
Recovery of Spent Nuclear Fuel Storage Costs		21.0	3.0	14.0
Current Amount Recoverable from the Federal Government		12.0	21.0
Noncurrent Amount Recoverable from the Federal Government		9.0	3.0
Spent Nuclear Fuel Disposal [Member] | Indiana Michigan Power Co [Member]
Commitments, Guarantees and Contingencies (Textuals)
DOE SNF Disposal Fee		0.0
Disposal, Assessed Fees and Related Interest		300.0	286.0
Trust Fund Assets One Time Fee Obligation for Nuclear Fuel Disposition		348.0	330.0
Recovery of Spent Nuclear Fuel Storage Costs		21.0	3.0	$ 14.0
Current Amount Recoverable from the Federal Government		12.0	21.0
Noncurrent Amount Recoverable from the Federal Government		9.0	$ 3.0
Nuclear Incident Liability [Member]
Commitments, Guarantees and Contingencies (Textuals)
Insurance Coverage for Property Damage, Decommissioning and Decontamination		2,700.0
Coverage for Property Damage, Decommissioning and Decontamination for a Nonnuclear Incident		500.0
Contingent Financial Obligation for Mutual Insurance		42.0
Insurance Protection for Public Liability Arising from a Nuclear Incident		16,300.0
Commercially Available Insurance		500.0
Assessed Amount per Nuclear Incident		332.0
Deferred Premium Assessment Annual Payment		49.0
Commercially Available Insurance for Catastrophic Nature		500.0
Liability Coverage Under the Price-Anderson Act		15,800.0
Nuclear Incident Liability [Member] | Indiana Michigan Power Co [Member]
Commitments, Guarantees and Contingencies (Textuals)
Insurance Coverage for Property Damage, Decommissioning and Decontamination		2,700.0
Coverage for Property Damage, Decommissioning and Decontamination for a Nonnuclear Incident		500.0
Contingent Financial Obligation for Mutual Insurance		42.0
Insurance Protection for Public Liability Arising from a Nuclear Incident		16,300.0
Commercially Available Insurance		500.0
Assessed Amount per Nuclear Incident		332.0
Deferred Premium Assessment Annual Payment		49.0
Commercially Available Insurance for Catastrophic Nature		500.0
Liability Coverage Under the Price-Anderson Act		15,800.0
March 2027 [Member] | Letters of Credit [Member]
Commitments, Guarantees and Contingencies (Textuals)
Revolving Credit Facilities		4,000.0
March 2025 [Member] | Letters of Credit [Member]
Commitments, Guarantees and Contingencies (Textuals)
Revolving Credit Facilities		$ 1,000.0

[1] Spent Nuclear Fuel Obligation consists of a liability along with accrued interest for disposal of SNF. See “Spent Nuclear Fuel Disposal” section of Note 6 for additional information.

[2] Represents contractual commitments to purchase coal, natural gas, uranium and other consumables as fuel for electric generation along with related transportation of the fuel.