Commitments, Guarantees and Contingencies (Details) $ in Millions	3 Months Ended
	Mar. 31, 2022 USD ($)
Maximum Potential Loss [Abstract]
Max Potential Loss on Master Lease Agreements	$ 47.2
Commitments, Guarantees and Contingencies (Textuals) [Abstract]
Rockport Plant, Unit 2 Acquisition Price	116.0
AEP Wind Holdings LLC [Member] | Generation And Marketing [Member]
Commitments, Guarantees and Contingencies (Textuals) [Abstract]
Maximum Potential Amount of Future Payments Associated with Guarantee	142.0
Guarantor Obligations, Current Carrying Value	27.0
Guarantor Obligations, Current Carrying Value, Contingent Portion	2.0
AEP Texas Inc. [Member]
Maximum Potential Loss [Abstract]
Max Potential Loss on Master Lease Agreements	11.0
Appalachian Power Co [Member]
Maximum Potential Loss [Abstract]
Max Potential Loss on Master Lease Agreements	6.1
Indiana Michigan Power Co [Member]
Maximum Potential Loss [Abstract]
Max Potential Loss on Master Lease Agreements	4.1
Commitments, Guarantees and Contingencies (Textuals) [Abstract]
Rockport Plant, Unit 2 Acquisition Price	116.0
Ohio Power Co [Member]
Maximum Potential Loss [Abstract]
Max Potential Loss on Master Lease Agreements	7.6
Public Service Co Of Oklahoma [Member]
Maximum Potential Loss [Abstract]
Max Potential Loss on Master Lease Agreements	4.6
Southwestern Electric Power Co [Member]
Maximum Potential Loss [Abstract]
Max Potential Loss on Master Lease Agreements	5.2
Rockport Lease [Member]
Present Value of Future Minimum Lease Payments, Sale Leaseback Transactions, Fiscal Year Maturity [Abstract]
Minimum Lease Payments, Sale Leaseback Transactions, Next Twelve Months	248.7	[1]
Minimum Lease Payments, Sale Leaseback Transactions	248.7	[1]
Rockport Lease [Member] | Indiana Michigan Power Co [Member]
Present Value of Future Minimum Lease Payments, Sale Leaseback Transactions, Fiscal Year Maturity [Abstract]
Minimum Lease Payments, Sale Leaseback Transactions, Next Twelve Months	124.4
Minimum Lease Payments, Sale Leaseback Transactions	124.4
Boat and Barge Leases [Member]
Commitments, Guarantees and Contingencies (Textuals) [Abstract]
Guarantor Obligations, Current Carrying Value	2.0
Maximum Potential Lease Payments, AEPRO Barge and Boat Leases	40.0
Guarantee Obligations Current Carrying Value Other Liabilities Current	1.0
Guarantee Obligations Current Carrying Value Other Liabilities Noncurrent	1.0
Letters of Credit [Member]
Maximum Future Payments for Letters of Credit [Abstract]
Maximum Future Payments for Letters of Credit Issued Under the Uncommitted Facility	308.7
Commitments, Guarantees and Contingencies (Textuals) [Abstract]
Letters of Credit Limit	1,200.0
Uncommitted Facility	400.0
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	2.2
March 2027 | Letters of Credit [Member]
Commitments, Guarantees and Contingencies (Textuals) [Abstract]
Revolving Credit Facilities	4,000.0
March 2024 | Letters of Credit [Member]
Commitments, Guarantees and Contingencies (Textuals) [Abstract]
Revolving Credit Facilities	$ 1,000.0

[1] AEP’s future minimum lease payments include equal shares from AEGCo and I&M.