Commitments, Guarantees and Contingencies (Details) $ in Millions	Sep. 30, 2023 USD ($)
Maximum Potential Loss [Abstract]
Max Potential Loss on Master Lease Agreements	$ 44.8
AEP Texas Inc. [Member]
Maximum Potential Loss [Abstract]
Max Potential Loss on Master Lease Agreements	10.9
Appalachian Power Co [Member]
Maximum Potential Loss [Abstract]
Max Potential Loss on Master Lease Agreements	5.6
Indiana Michigan Power Co [Member]
Maximum Potential Loss [Abstract]
Max Potential Loss on Master Lease Agreements	4.2
Ohio Power Co [Member]
Maximum Potential Loss [Abstract]
Max Potential Loss on Master Lease Agreements	6.9
Public Service Co Of Oklahoma [Member]
Maximum Potential Loss [Abstract]
Max Potential Loss on Master Lease Agreements	4.7
Southwestern Electric Power Co [Member]
Maximum Potential Loss [Abstract]
Max Potential Loss on Master Lease Agreements	5.3
Letters of Credit [Member]
Maximum Future Payments for Letters of Credit [Abstract]
Maximum Future Payments for Letters of Credit Issued Under the Uncommitted Facility	249.1
Commitments, Guarantees and Contingencies (Textuals) [Abstract]
Letters of Credit Limit	1,200.0
Uncommitted Facility	450.0
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	1.8
Letters of Credit [Member] | Appalachian Power Co [Member]
Maximum Future Payments for Letters of Credit [Abstract]
Maximum Future Payments for Letters of Credit Issued Under the Uncommitted Facility	6.3
Letters of Credit [Member] | Indiana Michigan Power Co [Member]
Maximum Future Payments for Letters of Credit [Abstract]
Maximum Future Payments for Letters of Credit Issued Under the Uncommitted Facility	2.9
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