EFFECTS OF REGULATION - Regulatory Asset - AEPTCO (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Regulatory Asset [Line Items]
Total Noncurrent Regulatory Assets	$ 5,129.2	$ 5,092.4
Approved for recovery
Regulatory Asset [Line Items]
Total Noncurrent Regulatory Assets	3,818.4	4,255.1
Does not earns/earning a return | Approved for recovery
Regulatory Asset [Line Items]
Total Noncurrent Regulatory Assets	2,106.9	2,308.2
AEP TRANSMISSION COMPANY, LLC
Regulatory Asset [Line Items]
Total Noncurrent Regulatory Assets	0.4	3.1
AEP TRANSMISSION COMPANY, LLC | Approved for recovery
Regulatory Asset [Line Items]
Total Noncurrent Regulatory Assets	0.4	3.1
AEP TRANSMISSION COMPANY, LLC | Does not earns/earning a return | Approved for recovery | PJM/SPP Annual Formula Rate True-up
Regulatory Asset [Line Items]
Total Noncurrent Regulatory Assets	$ 0.4	$ 3.1
Remaining Recovery Period	2 years