v3.25.2
FINANCING ACTIVITIES - Repayments and Retirements of Debt (Details) - USD ($)
$ in Millions
 6 Months Ended
Jun. 30, 2025
Jun. 30, 2024
Debt Instrument [Line Items]    
Principal Amount Paid $ 1,324.1 $ 1,769.1
AEP Texas    
Debt Instrument [Line Items]    
Principal Amount Paid 12.2 244.5
AEP Texas | 2.06% Securitization Bonds | Securitization Bonds    
Debt Instrument [Line Items]    
Principal Amount Paid $ 10.3  
Interest Rate 2.06%  
AEP Texas | 2.29% Securitization Bonds | Securitization Bonds    
Debt Instrument [Line Items]    
Principal Amount Paid $ 1.9  
Interest Rate 2.29%  
AEPTCo    
Debt Instrument [Line Items]    
Principal Amount Paid $ 90.0 0.0
AEPTCo | Senior Unsecured Notes    
Debt Instrument [Line Items]    
Interest Rate 5.38%  
AEPTCo | 3.66% Senior Unsecured Notes | Senior Unsecured Notes    
Debt Instrument [Line Items]    
Principal Amount Paid $ 50.0  
Interest Rate 3.66%  
AEPTCo | 3.76% Senior Unsecured Notes | Senior Unsecured Notes    
Debt Instrument [Line Items]    
Principal Amount Paid $ 40.0  
Interest Rate 3.76%  
APCo    
Debt Instrument [Line Items]    
Principal Amount Paid $ 418.4 399.5
APCo | Securitization Bonds    
Debt Instrument [Line Items]    
Principal Amount Paid $ 13.9  
Interest Rate 3.77%  
APCo | Senior Unsecured Notes    
Debt Instrument [Line Items]    
Principal Amount Paid $ 300.0  
Interest Rate 3.40%  
APCo | Other Long-term Debt    
Debt Instrument [Line Items]    
Principal Amount Paid $ 0.1  
Interest Rate 13.72%  
APCo | Pollution Control Bonds    
Debt Instrument [Line Items]    
Interest Rate 3.70%  
APCo | 3.75% Pollution Control Bonds | Pollution Control Bonds    
Debt Instrument [Line Items]    
Principal Amount Paid $ 104.4  
Interest Rate 3.75%  
I&M    
Debt Instrument [Line Items]    
Principal Amount Paid $ 240.0 48.6
I&M | Other Long-term Debt    
Debt Instrument [Line Items]    
Principal Amount Paid $ 0.2  
Interest Rate 6.00%  
I&M | Pollution Control Bonds    
Debt Instrument [Line Items]    
Interest Rate 3.70%  
I&M | Notes Payable    
Debt Instrument [Line Items]    
Interest Rate 4.89%  
I&M | Variable Note Payable | Notes Payable    
Debt Instrument [Line Items]    
Principal Amount Paid $ 1.1  
I&M | 0.93% Notes Payable | Notes Payable    
Debt Instrument [Line Items]    
Principal Amount Paid $ 2.6  
Interest Rate 0.93%  
I&M | 3.44% Notes Payable | Notes Payable    
Debt Instrument [Line Items]    
Principal Amount Paid $ 7.5  
Interest Rate 3.44%  
I&M | 5.93% Notes Payable | Notes Payable    
Debt Instrument [Line Items]    
Principal Amount Paid $ 8.7  
Interest Rate 5.93%  
I&M | 6.01% Notes Payable | Notes Payable    
Debt Instrument [Line Items]    
Principal Amount Paid $ 10.1  
Interest Rate 6.01%  
I&M | 6.41% Notes Payable | Notes Payable    
Debt Instrument [Line Items]    
Principal Amount Paid $ 16.3  
Interest Rate 6.41%  
I&M | 4.89% Note Payable | Notes Payable    
Debt Instrument [Line Items]    
Principal Amount Paid $ 3.5  
Interest Rate 4.89%  
I&M | 0.75% Pollution Control Bonds | Pollution Control Bonds    
Debt Instrument [Line Items]    
Principal Amount Paid $ 40.0  
Interest Rate 0.75%  
I&M | 2.75% Pollution Control Bonds | Pollution Control Bonds    
Debt Instrument [Line Items]    
Principal Amount Paid $ 50.0  
Interest Rate 2.75%  
I&M | 3.05% Pollution Control Bonds | Pollution Control Bonds    
Debt Instrument [Line Items]    
Principal Amount Paid $ 100.0  
Interest Rate 3.05%  
PSO    
Debt Instrument [Line Items]    
Principal Amount Paid $ 125.3 $ 0.3
PSO | Senior Unsecured Notes    
Debt Instrument [Line Items]    
Interest Rate 5.45%  
PSO | Other Long-term Debt    
Debt Instrument [Line Items]    
Principal Amount Paid $ 0.3  
Interest Rate 3.00%  
PSO | 3.17% Senior Unsecured Notes | Senior Unsecured Notes    
Debt Instrument [Line Items]    
Principal Amount Paid $ 125.0  
Interest Rate 3.17%  
KPCo | Securitization Bonds    
Debt Instrument [Line Items]    
Interest Rate 5.30%  
KPCo | Variable Other Long-term Debt | Other Long-term Debt    
Debt Instrument [Line Items]    
Principal Amount Paid $ 150.0  
Transource Energy | 2.75 % Senior Unsecured Notes | Senior Unsecured Notes    
Debt Instrument [Line Items]    
Principal Amount Paid $ 1.2  
Interest Rate 2.75%  
WPCo | 3.70% Senior Unsecured Notes | Senior Unsecured Notes    
Debt Instrument [Line Items]    
Principal Amount Paid $ 122.0  
Interest Rate 3.70%  
WPCo | 6.89% Notes Payable | Notes Payable    
Debt Instrument [Line Items]    
Principal Amount Paid $ 15.0  
Interest Rate 6.89%