v3.25.2
BUSINESS SEGMENTS - Schedule of AEPTCo's Reportable Segment Information (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2025
Jun. 30, 2024
Jun. 30, 2025
Jun. 30, 2024
Dec. 31, 2024
Segment Reporting Information [Line Items]          
Total Revenues $ 5,086.9 $ 4,579.2 $ 10,550.3 $ 9,604.9  
Other Operation and Maintenance 928.3 1,168.8 1,999.2 2,248.6  
Depreciation and Amortization 853.1 821.9 1,686.5 1,609.0  
Taxes Other Than Income Taxes 365.0 393.6 787.0 804.0  
Allowance for Equity Funds Used During Construction 57.1 55.2 114.4 98.8  
Interest Expense 489.5 465.6 984.4 901.2  
Income Tax Expense (Benefit) (250.9) 6.7 (125.4) (135.2)  
Other Segment Items 12.4 (48.3) (28.5) (104.4)  
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  
Gross Property Additions 3,279.3 1,556.6 5,379.5 3,318.3  
Total Assets 107,778.5   107,778.5   $ 103,078.0
Nonrelated Party          
Segment Reporting Information [Line Items]          
Total Revenues 5,086.9 4,579.2 10,550.3 9,604.9  
Operating Segments          
Segment Reporting Information [Line Items]          
Total Revenues 5,788.2 5,012.3 11,741.5 10,511.2  
Other Operation and Maintenance 1,567.6 1,562.0 3,095.9 3,035.1  
Depreciation and Amortization 858.2 827.1 1,696.6 1,619.5  
Taxes Other Than Income Taxes 359.7 388.6 774.8 794.3  
Allowance for Equity Funds Used During Construction 57.1 55.2 114.4 98.8  
Interest Expense 361.7 344.2 732.8 660.5  
Income Tax Expense (Benefit) (206.6) 32.4 (24.8) (62.9)  
Other Segment Items 12.9 (57.3) (32.8) (117.5)  
Earnings Attributable to AEP Common Shareholders, Basic 1,297.1 408.4 2,122.8 1,465.8  
Earnings Attributable to AEP Common Shareholders, Diluted 1,297.1 408.4 2,122.8 1,465.8  
Gross Property Additions 3,282.7 1,563.0 5,341.5 3,316.6  
Total Assets 106,038.7   106,038.7   101,506.6
Operating Segments | Nonrelated Party          
Segment Reporting Information [Line Items]          
Total Revenues 5,083.2 4,552.0 10,530.7 9,562.8  
Corporate and Other          
Segment Reporting Information [Line Items]          
Total Revenues 29.6 57.7 74.2 110.5  
Other Operation and Maintenance 20.5 24.9 36.3 61.0  
Depreciation and Amortization (5.0) (5.2) (10.1) (10.5)  
Taxes Other Than Income Taxes 0.1 0.1 0.6 0.2  
Allowance for Equity Funds Used During Construction 0.0 0.0 0.0 0.0  
Interest Expense 151.1 155.3 298.1 311.1  
Income Tax Expense (Benefit) (44.3) (25.7) (100.6) (72.3)  
Other Segment Items (23.8) (24.9) (42.2) (57.3)  
Earnings Attributable to AEP Common Shareholders, Basic (71.3) (68.1) (96.8) (122.4)  
Earnings Attributable to AEP Common Shareholders, Diluted (71.3) (68.1) (96.8) (122.4)  
Gross Property Additions 5.8 6.4 35.8 9.5  
Total Assets 5,316.2   5,316.2   5,550.8
Corporate and Other | Nonrelated Party          
Segment Reporting Information [Line Items]          
Total Revenues 3.7 27.2 19.6 42.1  
Reconciling Adjustments          
Segment Reporting Information [Line Items]          
Total Revenues (730.9) (490.8) (1,265.4) (1,016.8)  
Other Operation and Maintenance (659.8) (418.1) (1,133.0) (847.5)  
Depreciation and Amortization (0.1) 0.0 0.0 0.0  
Taxes Other Than Income Taxes 5.2 4.9 11.6 9.5  
Allowance for Equity Funds Used During Construction 0.0 0.0 0.0 0.0  
Interest Expense (23.3) (33.9) (46.5) (70.4)  
Income Tax Expense (Benefit) 0.0 0.0 0.0 0.0  
Other Segment Items 23.3 33.9 46.5 70.4  
Earnings Attributable to AEP Common Shareholders, Basic 0.0 0.0 0.0 0.0  
Earnings Attributable to AEP Common Shareholders, Diluted 0.0 0.0 0.0 0.0  
Gross Property Additions (9.2) (12.8) 2.2 (7.8)  
Total Assets (3,576.4)   (3,576.4)   (3,979.4)
Reconciling Adjustments | Nonrelated Party          
Segment Reporting Information [Line Items]          
Total Revenues 0.0 0.0 0.0 0.0  
AEPTCo          
Segment Reporting Information [Line Items]          
Total Revenues 741.8 475.2 1,268.9 958.0  
Other Revenues 0.1 0.4 0.1 2.8  
Other Operation and Maintenance 42.2 45.0 76.6 80.2  
Depreciation and Amortization 118.9 106.7 233.0 212.6  
Taxes Other Than Income Taxes 75.8 75.5 149.9 148.9  
Interest Income 1.4 4.3 1.8 6.2  
Allowance for Equity Funds Used During Construction 21.5 22.5 43.9 40.4  
Interest Expense 56.6 51.4 111.6 106.2  
Income Tax Expense (Benefit) (145.3) 47.7 (84.5) 99.8  
Other Segment Items 60.7   60.7    
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  
Gross Property Additions 365.1 321.3 786.9 657.8  
Total Assets 17,032.8   17,032.8   16,370.3
AEPTCo | Nonrelated Party          
Segment Reporting Information [Line Items]          
Total Revenues 144.6 97.0 248.9 194.0  
AEPTCo | Affiliated Entity          
Segment Reporting Information [Line Items]          
Total Revenues 597.1 377.8 1,019.9 761.2  
AEPTCo | Corporate and Other          
Segment Reporting Information [Line Items]          
Total Revenues 0.0 0.0 0.0 0.0  
Other Revenues 0.0 0.0 0.0 0.0  
Other Operation and Maintenance 0.0 0.1 0.2 1.6  
Depreciation and Amortization 0.0 0.0 0.0 0.0  
Taxes Other Than Income Taxes 0.0 0.0 0.0 0.0  
Interest Income 84.0 61.7 173.3 118.8  
Allowance for Equity Funds Used During Construction 0.0 0.0 0.0 0.0  
Interest Expense 62.6 60.9 122.6 117.2  
Income Tax Expense (Benefit) 10.7 0.2 10.7 0.0  
Other Segment Items 60.7   60.7    
Earnings Attributable to AEP Common Shareholders, Basic (50.0) 0.5 (20.9) 0.0  
Earnings Attributable to AEP Common Shareholders, Diluted (50.0) 0.5 (20.9) 0.0  
Gross Property Additions 0.0 0.0 0.0 0.0  
Total Assets 6,241.3   6,241.3   8,670.4
AEPTCo | Corporate and Other | Nonrelated Party          
Segment Reporting Information [Line Items]          
Total Revenues 0.0 0.0 0.0 0.0  
AEPTCo | Corporate and Other | Affiliated Entity          
Segment Reporting Information [Line Items]          
Total Revenues 0.0 0.0 0.0 0.0  
AEPTCo | Reconciling Adjustments          
Segment Reporting Information [Line Items]          
Total Revenues 0.0 0.0 0.0 0.0  
Other Revenues 0.0 0.0 0.0 0.0  
Other Operation and Maintenance 0.0 0.0 0.0 0.0  
Depreciation and Amortization 0.0 0.0 0.0 0.0  
Taxes Other Than Income Taxes 0.0 0.0 0.0 0.0  
Interest Income (83.5) (60.9) (172.5) (117.1)  
Allowance for Equity Funds Used During Construction 0.0 0.0 0.0 0.0  
Interest Expense (83.5) (60.9) (172.5) (117.1)  
Income Tax Expense (Benefit) 0.0 0.0 0.0 0.0  
Other Segment Items 0.0   0.0    
Earnings Attributable to AEP Common Shareholders, Basic 0.0 0.0 0.0 0.0  
Earnings Attributable to AEP Common Shareholders, Diluted 0.0 0.0 0.0 0.0  
Gross Property Additions 0.0 0.0 0.0 0.0  
Total Assets (6,288.6)   (6,288.6)   (9,187.8)
AEPTCo | Reconciling Adjustments | Nonrelated Party          
Segment Reporting Information [Line Items]          
Total Revenues 0.0 0.0 0.0 0.0  
AEPTCo | Reconciling Adjustments | Affiliated Entity          
Segment Reporting Information [Line Items]          
Total Revenues 0.0 0.0 0.0 0.0  
State Transcos | AEPTCo | Operating Segments          
Segment Reporting Information [Line Items]          
Total Revenues 741.8 475.2 1,268.9 958.0  
Other Revenues 0.1 0.4 0.1 2.8  
Other Operation and Maintenance 42.2 44.9 76.4 78.6  
Depreciation and Amortization 118.9 106.7 233.0 212.6  
Taxes Other Than Income Taxes 75.8 75.5 149.9 148.9  
Interest Income 0.9 3.5 1.0 4.5  
Allowance for Equity Funds Used During Construction 21.5 22.5 43.9 40.4  
Interest Expense 77.5 51.4 161.5 106.1  
Income Tax Expense (Benefit) (156.0) 47.5 (95.2) 99.8  
Other Segment Items 0.0   0.0    
Earnings Attributable to AEP Common Shareholders, Basic 605.8 175.2 788.2 356.9  
Earnings Attributable to AEP Common Shareholders, Diluted 605.8 175.2 788.2 356.9  
Gross Property Additions 365.1 321.3 786.9 657.8  
Total Assets 17,080.1   17,080.1   $ 16,887.7
State Transcos | AEPTCo | Operating Segments | Nonrelated Party          
Segment Reporting Information [Line Items]          
Total Revenues 144.6 97.0 248.9 194.0  
State Transcos | AEPTCo | Operating Segments | Affiliated Entity          
Segment Reporting Information [Line Items]          
Total Revenues $ 597.1 $ 377.8 $ 1,019.9 $ 761.2