v3.25.2
RATE MATTERS - Impact to the Statements of Income Recorded by the Registrants (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2025
Mar. 31, 2025
Jun. 30, 2024
Mar. 31, 2024
Jun. 30, 2025
Jun. 30, 2024
Regulatory Asset [Line Items]            
Total Revenues $ 5,086.9   $ 4,579.2   $ 10,550.3 $ 9,604.9
Purchased Electricity, Fuel and Other Consumables Used for Electric Generation (1,541.4)   (1,368.5)   (3,394.3) (2,944.3)
INCOME BEFORE INCOME TAX EXPENSE (BENEFIT) AND EQUITY EARNINGS 1,016.8   324.0   1,906.3 1,163.3
Income Tax Expense (Benefit) (250.9)   6.7   (125.4) (135.2)
Net Income (Loss) 1,288.3 $ 802.2 342.5 $ 1,005.7 2,090.5 1,348.2
Net Income Attributable to Noncontrolling Interest 62.5   2.2   64.5 4.8
EARNINGS ATTRIBUTABLE TO AEP COMMON SHAREHOLDERS, Basic 1,225.8   340.3   2,026.0 1,343.4
EARNINGS ATTRIBUTABLE TO AEP COMMON SHAREHOLDERS, Diluted 1,225.8   340.3   2,026.0 1,343.4
FERC 2021 PJM and SPP Transmission Formula Rate Challenge            
Regulatory Asset [Line Items]            
Total Revenues 270.5          
Purchased Electricity, Fuel and Other Consumables Used for Electric Generation (23.9)          
Other Operation 53.0          
INCOME BEFORE INCOME TAX EXPENSE (BENEFIT) AND EQUITY EARNINGS 241.4          
Income Tax Expense (Benefit) (312.8)          
Net Income (Loss) 554.2          
Net Income Attributable to Noncontrolling Interest 55.2          
EARNINGS ATTRIBUTABLE TO AEP COMMON SHAREHOLDERS, Basic 499.0          
EARNINGS ATTRIBUTABLE TO AEP COMMON SHAREHOLDERS, Diluted 499.0          
AEPTCo            
Regulatory Asset [Line Items]            
Total Revenues 741.8   475.2   1,268.9 958.0
INCOME BEFORE INCOME TAX EXPENSE (BENEFIT) AND EQUITY EARNINGS 471.2   223.4   743.5 456.7
Income Tax Expense (Benefit) (145.3)   47.7   (84.5) 99.8
Net Income (Loss) 616.5 211.5 175.7 181.2 828.0 356.9
Net Income Attributable to Noncontrolling Interest 60.7   0.0   60.7 0.0
EARNINGS ATTRIBUTABLE TO AEP COMMON SHAREHOLDERS, Basic 555.8   175.7   767.3 356.9
EARNINGS ATTRIBUTABLE TO AEP COMMON SHAREHOLDERS, Diluted 555.8   175.7   767.3 356.9
AEPTCo | FERC 2021 PJM and SPP Transmission Formula Rate Challenge            
Regulatory Asset [Line Items]            
Total Revenues 214.3          
Purchased Electricity, Fuel and Other Consumables Used for Electric Generation 0.0          
Other Operation 0.0          
INCOME BEFORE INCOME TAX EXPENSE (BENEFIT) AND EQUITY EARNINGS 214.3          
Income Tax Expense (Benefit) (203.2)          
Net Income (Loss) 417.5          
Net Income Attributable to Noncontrolling Interest 55.2          
EARNINGS ATTRIBUTABLE TO AEP COMMON SHAREHOLDERS, Basic 362.3          
EARNINGS ATTRIBUTABLE TO AEP COMMON SHAREHOLDERS, Diluted 362.3          
APCo            
Regulatory Asset [Line Items]            
Total Revenues 947.6   910.2   2,120.5 2,003.2
Purchased Electricity, Fuel and Other Consumables Used for Electric Generation (290.8)   (304.8)   (698.0) (701.6)
INCOME BEFORE INCOME TAX EXPENSE (BENEFIT) AND EQUITY EARNINGS 93.2   71.0   298.5 221.5
Income Tax Expense (Benefit) (13.7)   12.7   27.0 26.7
APCo | FERC 2021 PJM and SPP Transmission Formula Rate Challenge            
Regulatory Asset [Line Items]            
Total Revenues 5.6          
Purchased Electricity, Fuel and Other Consumables Used for Electric Generation (17.2)          
Other Operation 14.8          
INCOME BEFORE INCOME TAX EXPENSE (BENEFIT) AND EQUITY EARNINGS 8.0          
Income Tax Expense (Benefit) (21.4)          
Net Income (Loss) 29.4          
Net Income Attributable to Noncontrolling Interest 0.0          
EARNINGS ATTRIBUTABLE TO AEP COMMON SHAREHOLDERS, Basic 29.4          
EARNINGS ATTRIBUTABLE TO AEP COMMON SHAREHOLDERS, Diluted 29.4          
I&M            
Regulatory Asset [Line Items]            
Total Revenues 737.2   594.3   1,459.4 1,261.7
INCOME BEFORE INCOME TAX EXPENSE (BENEFIT) AND EQUITY EARNINGS 92.9   26.6   157.1 131.4
Income Tax Expense (Benefit) (31.2)   (8.6)   (24.5) (48.8)
I&M | FERC 2021 PJM and SPP Transmission Formula Rate Challenge            
Regulatory Asset [Line Items]            
Total Revenues 10.8          
Purchased Electricity, Fuel and Other Consumables Used for Electric Generation 0.0          
Other Operation (6.0)          
INCOME BEFORE INCOME TAX EXPENSE (BENEFIT) AND EQUITY EARNINGS 16.8          
Income Tax Expense (Benefit) (27.8)          
Net Income (Loss) 44.6          
Net Income Attributable to Noncontrolling Interest 0.0          
EARNINGS ATTRIBUTABLE TO AEP COMMON SHAREHOLDERS, Basic 44.6          
EARNINGS ATTRIBUTABLE TO AEP COMMON SHAREHOLDERS, Diluted 44.6          
OPCo            
Regulatory Asset [Line Items]            
Total Revenues 919.0   896.3   1,922.5 1,920.1
INCOME BEFORE INCOME TAX EXPENSE (BENEFIT) AND EQUITY EARNINGS 125.7   16.6   201.3 100.4
Income Tax Expense (Benefit) 23.0   (2.6)   36.9 10.6
OPCo | FERC 2021 PJM and SPP Transmission Formula Rate Challenge            
Regulatory Asset [Line Items]            
Total Revenues 0.0          
Purchased Electricity, Fuel and Other Consumables Used for Electric Generation 0.0          
Other Operation 0.1          
INCOME BEFORE INCOME TAX EXPENSE (BENEFIT) AND EQUITY EARNINGS (0.1)          
Income Tax Expense (Benefit) 0.0          
Net Income (Loss) (0.1)          
Net Income Attributable to Noncontrolling Interest 0.0          
EARNINGS ATTRIBUTABLE TO AEP COMMON SHAREHOLDERS, Basic (0.1)          
EARNINGS ATTRIBUTABLE TO AEP COMMON SHAREHOLDERS, Diluted (0.1)          
PSO            
Regulatory Asset [Line Items]            
Total Revenues 469.5   458.8   863.5 846.6
Purchased Electricity, Fuel and Other Consumables Used for Electric Generation (172.3)   (180.0)   (301.3) (328.9)
INCOME BEFORE INCOME TAX EXPENSE (BENEFIT) AND EQUITY EARNINGS 33.5   23.1   59.0 41.6
Income Tax Expense (Benefit) (30.2)   (13.2)   (32.2) (66.7)
PSO | FERC 2021 PJM and SPP Transmission Formula Rate Challenge            
Regulatory Asset [Line Items]            
Total Revenues 6.4          
Purchased Electricity, Fuel and Other Consumables Used for Electric Generation 0.0          
Other Operation 18.8          
INCOME BEFORE INCOME TAX EXPENSE (BENEFIT) AND EQUITY EARNINGS (12.4)          
Income Tax Expense (Benefit) (15.6)          
Net Income (Loss) 3.2          
Net Income Attributable to Noncontrolling Interest 0.0          
EARNINGS ATTRIBUTABLE TO AEP COMMON SHAREHOLDERS, Basic 3.2          
EARNINGS ATTRIBUTABLE TO AEP COMMON SHAREHOLDERS, Diluted 3.2          
SWEPCo            
Regulatory Asset [Line Items]            
Total Revenues 570.4   395.8   1,101.5 912.0
Purchased Electricity, Fuel and Other Consumables Used for Electric Generation (192.5)   (193.4)   (383.4) (378.0)
INCOME BEFORE INCOME TAX EXPENSE (BENEFIT) AND EQUITY EARNINGS 57.8   (113.6)   100.7 (48.5)
Income Tax Expense (Benefit) (58.3)   (44.2)   (64.6) (188.3)
Net Income (Loss) 116.4 $ 49.5 (69.1) $ 209.6 165.9 140.5
Net Income Attributable to Noncontrolling Interest 0.8   1.0   1.8 2.5
EARNINGS ATTRIBUTABLE TO AEP COMMON SHAREHOLDERS, Basic 115.6   (70.1)   164.1 138.0
EARNINGS ATTRIBUTABLE TO AEP COMMON SHAREHOLDERS, Diluted 115.6   $ (70.1)   $ 164.1 $ 138.0
SWEPCo | FERC 2021 PJM and SPP Transmission Formula Rate Challenge            
Regulatory Asset [Line Items]            
Total Revenues 26.9          
Purchased Electricity, Fuel and Other Consumables Used for Electric Generation 0.0          
Other Operation 10.1          
INCOME BEFORE INCOME TAX EXPENSE (BENEFIT) AND EQUITY EARNINGS 16.8          
Income Tax Expense (Benefit) (38.9)          
Net Income (Loss) 55.7          
Net Income Attributable to Noncontrolling Interest 0.0          
EARNINGS ATTRIBUTABLE TO AEP COMMON SHAREHOLDERS, Basic 55.7          
EARNINGS ATTRIBUTABLE TO AEP COMMON SHAREHOLDERS, Diluted $ 55.7