Commitments, Guarantees and Contingencies (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Contractual Commitments
Less than 1 year		$ 854.2
For 2-3 years		894.4
For 4-5 years		459.5
After 5 years		966.2
Total Contractual Commitments		3,174.3
Commitments, Guarantees and Contingencies (Textuals)
Revolving Credit Facilities		5,000.0
Disposal, Assessed Fees and Related Interest	[1]	281.3	$ 281.2
Rockport Plant, Unit 2 Acquisition Price		116.0
AEP Wind Holdings LLC [Member] | Generation and Marketing [Member]
Commitments, Guarantees and Contingencies (Textuals)
Maximum Potential Amount of Future Payments Associated with Guarantee		142.0
Guarantor Obligations, Current Carrying Value		28.0
Guarantor Obligations, Current Carrying Value, Contingent Portion		2.0
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		168.5
Commitments, Guarantees and Contingencies (Textuals)
Letters of Credit Limit		1,200.0
Uncommitted Facility		375.0
Letters of Credit [Member] | Subsequent Event [Member]
Commitments, Guarantees and Contingencies (Textuals)
Uncommitted Facility		400.0
Fuel Purchase Contracts [Member]
Contractual Commitments
Less than 1 year	[2],[3],[4]	706.4
For 2-3 years	[2],[3],[4]	584.9
For 4-5 years	[2],[3],[4]	167.8
After 5 years	[2],[3],[4]	301.8
Total Contractual Commitments	[2],[3],[4]	1,760.9
Energy and Capacity Purchase Contracts [Member]
Contractual Commitments
Less than 1 year		147.8
For 2-3 years		309.5
For 4-5 years		291.7
After 5 years		664.4
Total Contractual Commitments		1,413.4
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		2.2
Appalachian Power Co [Member]
Contractual Commitments
Less than 1 year		307.3
For 2-3 years		253.6
For 4-5 years		99.1
After 5 years		168.4
Total Contractual Commitments		828.4
Appalachian Power Co [Member] | Fuel Purchase Contracts [Member]
Contractual Commitments
Less than 1 year	[2],[4]	266.9
For 2-3 years	[2],[4]	171.8
For 4-5 years	[2],[4]	18.7
After 5 years	[2],[4]	18.4
Total Contractual Commitments	[2],[4]	475.8
Appalachian Power Co [Member] | Fuel Purchase Contracts [Member] | Subsequent Event [Member]
Contractual Commitments
Less than 1 year		95.0
For 2-3 years		449.0
For 4-5 years		96.0
Appalachian Power Co [Member] | Energy and Capacity Purchase Contracts [Member]
Contractual Commitments
Less than 1 year		40.4
For 2-3 years		81.8
For 4-5 years		80.4
After 5 years		150.0
Total Contractual Commitments		352.6
Indiana Michigan Power Co [Member]
Contractual Commitments
Less than 1 year		314.9
For 2-3 years		458.3
For 4-5 years		352.4
After 5 years		589.2
Total Contractual Commitments		1,714.8
Commitments, Guarantees and Contingencies (Textuals)
Disposal, Assessed Fees and Related Interest	[1]	281.3	281.2
Rockport Plant, Unit 2 Acquisition Price		116.0
Indiana Michigan Power Co [Member] | Fuel Purchase Contracts [Member]
Contractual Commitments
Less than 1 year	[4]	147.7
For 2-3 years	[4]	245.7
For 4-5 years	[4]	149.1
After 5 years	[4]	283.3
Total Contractual Commitments	[4]	825.8
Indiana Michigan Power Co [Member] | Energy and Capacity Purchase Contracts [Member]
Contractual Commitments
Less than 1 year		167.2
For 2-3 years		212.6
For 4-5 years		203.3
After 5 years		305.9
Total Contractual Commitments		889.0
Ohio Power Co [Member] | Energy and Capacity Purchase Contracts [Member]
Contractual Commitments
Less than 1 year		34.6
For 2-3 years		69.1
For 4-5 years		65.4
After 5 years		180.0
Total Contractual Commitments		349.1
Public Service Co Of Oklahoma [Member]
Contractual Commitments
Less than 1 year		80.4
For 2-3 years		90.3
For 4-5 years		67.9
After 5 years		125.9
Total Contractual Commitments		364.5
Public Service Co Of Oklahoma [Member] | Fuel Purchase Contracts [Member]
Contractual Commitments
Less than 1 year	[4]	48.2
For 2-3 years	[4]	23.0
For 4-5 years	[4]	0.0
After 5 years	[4]	0.0
Total Contractual Commitments	[4]	71.2
Public Service Co Of Oklahoma [Member] | Energy and Capacity Purchase Contracts [Member]
Contractual Commitments
Less than 1 year		32.2
For 2-3 years		67.3
For 4-5 years		67.9
After 5 years		125.9
Total Contractual Commitments		293.3
Southwestern Electric Power Co [Member]
Contractual Commitments
Less than 1 year		163.0
For 2-3 years		99.7
For 4-5 years		8.4
After 5 years		0.0
Total Contractual Commitments		271.1
Southwestern Electric Power Co [Member] | Fuel Purchase Contracts [Member]
Contractual Commitments
Less than 1 year	[4]	158.8
For 2-3 years	[4]	91.3
For 4-5 years	[4]	0.0
After 5 years	[4]	0.0
Total Contractual Commitments	[4]	250.1
Southwestern Electric Power Co [Member] | Energy and Capacity Purchase Contracts [Member]
Contractual Commitments
Less than 1 year		4.2
For 2-3 years		8.4
For 4-5 years		8.4
After 5 years		0.0
Total Contractual Commitments		21.0
Kentucky Power Co [Member] | Fuel Purchase Contracts [Member]
Contractual Commitments
Less than 1 year		22.0
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		4.0	4.0	$ 7.0
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		4.0	4.0	7.0
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		281.0	281.0
Trust Fund Assets One Time Fee Obligation for Nuclear Fuel Disposition		329.0	324.0
Recovery of Spent Nuclear Fuel Storage Costs		14.0	24.0	8.0
Current Amount Recoverable from the Federal Government		3.0	14.0
Noncurrent Amount Recoverable from the Federal Government		21.0	1.0
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		281.0	281.0
Trust Fund Assets One Time Fee Obligation for Nuclear Fuel Disposition		329.0	324.0
Recovery of Spent Nuclear Fuel Storage Costs		14.0	24.0	$ 8.0
Current Amount Recoverable from the Federal Government		3.0	14.0
Noncurrent Amount Recoverable from the Federal Government		21.0	$ 1.0
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		13,500.0
Commercially Available Insurance		450.0
Assessed Amount per Nuclear Incident		275.0
Deferred Premium Assessment Annual Payment		41.0
Commercially Available Insurance for Catastrophic Nature		450.0
Liability Coverage Under the Price-Anderson Act		13,100.0
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		13,500.0
Commercially Available Insurance		450.0
Assessed Amount per Nuclear Incident		275.0
Deferred Premium Assessment Annual Payment		41.0
Commercially Available Insurance for Catastrophic Nature		450.0
Liability Coverage Under the Price-Anderson Act		13,100.0
March 2026 [Member] | Letters of Credit [Member]
Commitments, Guarantees and Contingencies (Textuals)
Revolving Credit Facilities		4,000.0
March 2023 [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] In the first quarter of 2022, APCo entered into new fuel purchase contracts related to coal procurement. The new commitments were as follows: $95 million in less than 1 year, $449 million in 2-3 years and $96 million in 4-5 years. These commitments are not included in the tables above. All other new commitments in the first quarter of 2022 were immaterial.

[3] Includes $22 million of purchase fuel contracts for KPCo commitments that are expected to occur prior to the anticipated closing of the sale transaction in the second quarter of 2022. See “Disposition of KPCo and KTCo” section of Note 7 for additional information.

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