Commitments, Guarantees and Contingencies (Details) $ in Millions	Mar. 31, 2024 USD ($)
Maximum Potential Loss [Abstract]
Max Potential Loss on Master Lease Agreements	$ 44.6
AEP Texas Inc. [Member]
Maximum Potential Loss [Abstract]
Max Potential Loss on Master Lease Agreements	10.7
Appalachian Power Co [Member]
Maximum Potential Loss [Abstract]
Max Potential Loss on Master Lease Agreements	5.8
Indiana Michigan Power Co [Member]
Maximum Potential Loss [Abstract]
Max Potential Loss on Master Lease Agreements	4.1
Ohio Power Co [Member]
Maximum Potential Loss [Abstract]
Max Potential Loss on Master Lease Agreements	7.1
Public Service Co Of Oklahoma [Member]
Maximum Potential Loss [Abstract]
Max Potential Loss on Master Lease Agreements	4.5
Southwestern Electric Power Co [Member]
Maximum Potential Loss [Abstract]
Max Potential Loss on Master Lease Agreements	5.1
Letters of Credit [Member]
Maximum Future Payments for Letters of Credit [Abstract]
Maximum Future Payments for Letters of Credit Issued Under the Uncommitted Facility	247.4
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 2029 [Member] | Letters of Credit [Member]
Commitments, Guarantees and Contingencies (Textuals) [Abstract]
Revolving Credit Facilities	5,000.0
March 2027 [Member] | Letters of Credit [Member]
Commitments, Guarantees and Contingencies (Textuals) [Abstract]
Prior Revolving Credit Facilities	4,000.0
Revolving Credit Facilities	$ 1,000.0