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Revenue from Contracts with Customers (Details) - USD ($)
$ in Millions
 3 Months Ended
Mar. 31, 2020
Mar. 31, 2019
Dec. 31, 2019
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers $ 3,747.5 $ 4,056.8  
Revenue Not from Contract with Customer, Other 40.6 10.9  
Total Revenues 3,747.5 4,056.8  
Revenue, Performance Obligation [Abstract]      
Fixed Performance Obligations 1,287.5    
Revenue Textuals [Abstract]      
Revenue from Related Parties 0.0 0.0  
2020 [Member]      
Revenue, Performance Obligation [Abstract]      
Fixed Performance Obligations 732.4    
2021-2022 [Member]      
Revenue, Performance Obligation [Abstract]      
Fixed Performance Obligations 171.1    
2023-2024 [Member]      
Revenue, Performance Obligation [Abstract]      
Fixed Performance Obligations 160.6    
2024 and Forward [Member]      
Revenue, Performance Obligation [Abstract]      
Fixed Performance Obligations 223.4    
Retail [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 2,870.2 3,102.8  
Residential [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 1,436.4 1,568.5  
Commercial [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 766.3 822.1  
Industrial [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 615.8 657.8  
Other Retail [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 51.7 54.4  
Wholesale and Competitive [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 765.2 865.0  
Generation [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 184.5 294.7  
Transmission [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 240.8 [1] 208.8 [2]  
Renewable Generation [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 16.6 [3] 7.8 [4]  
Retail, Trading and Marketing Revenues [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 323.3 [5] 353.7 [6]  
Other Revenues [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 71.5 [3] 78.1 [4]  
Affiliated and Nonaffiliated [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 3,706.9 4,045.9  
Alternative [Member]      
Disaggregation of Revenue [Abstract]      
Revenue Not from Contract with Customer, Other 20.7 [3] (0.2) [4]  
Other Revenues [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 70.9 65.0  
Revenue Not from Contract with Customer, Other 19.9 [3] 11.1 [4]  
AEP Texas Inc. [Member]      
Disaggregation of Revenue [Abstract]      
Revenue Not from Contract with Customer, Other 29.5 38.9  
Total Revenues 423.6 390.7  
Revenue, Performance Obligation [Abstract]      
Fixed Performance Obligations 290.3    
Assets, Current [Abstract]      
Affiliated Companies - Contracts with Customers 10.4   $ 10.1
Revenue Textuals [Abstract]      
Revenue from Related Parties 31.1 40.2  
AEP Texas Inc. [Member] | 2020 [Member]      
Revenue, Performance Obligation [Abstract]      
Fixed Performance Obligations 290.3    
AEP Texas Inc. [Member] | 2021-2022 [Member]      
Revenue, Performance Obligation [Abstract]      
Fixed Performance Obligations 0.0    
AEP Texas Inc. [Member] | 2023-2024 [Member]      
Revenue, Performance Obligation [Abstract]      
Fixed Performance Obligations 0.0    
AEP Texas Inc. [Member] | 2024 and Forward [Member]      
Revenue, Performance Obligation [Abstract]      
Fixed Performance Obligations 0.0    
AEP Texas Inc. [Member] | Retail [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 289.3 259.1  
AEP Texas Inc. [Member] | Residential [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 132.9 120.9  
AEP Texas Inc. [Member] | Commercial [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 112.8 97.9  
AEP Texas Inc. [Member] | Industrial [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 35.2 33.0  
AEP Texas Inc. [Member] | Other Retail [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 8.4 7.3  
AEP Texas Inc. [Member] | Wholesale and Competitive [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 96.9 85.8  
AEP Texas Inc. [Member] | Generation [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 0.0 [7] 0.0 [8]  
AEP Texas Inc. [Member] | Transmission [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 96.9 [9] 85.8 [10]  
AEP Texas Inc. [Member] | Other Revenues [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 7.9 [11] 6.9 [12]  
AEP Texas Inc. [Member] | Affiliated and Nonaffiliated [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 394.1 351.8  
AEP Texas Inc. [Member] | Alternative [Member]      
Disaggregation of Revenue [Abstract]      
Revenue Not from Contract with Customer, Other (0.7) [13] (0.9) [14]  
AEP Texas Inc. [Member] | Other Revenues [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 0.9 0.7  
Revenue Not from Contract with Customer, Other 30.2 [13] 39.8 [14]  
AEP Transmission Co [Member]      
Disaggregation of Revenue [Abstract]      
Revenue Not from Contract with Customer, Other (6.0) (1.7)  
Total Revenues 295.6 243.5  
Revenue, Performance Obligation [Abstract]      
Fixed Performance Obligations 821.5    
Assets, Current [Abstract]      
Affiliated Companies - Contracts with Customers 87.8   66.1
Revenue Textuals [Abstract]      
Revenue from Related Parties 233.7 193.2  
AEP Transmission Co [Member] | Short-term Contract with Customer [Member]      
Assets, Current [Abstract]      
Affiliated Companies - Contracts with Customers 80.6   65.9
AEP Transmission Co [Member] | 2020 [Member]      
Revenue, Performance Obligation [Abstract]      
Fixed Performance Obligations 821.5    
AEP Transmission Co [Member] | 2021-2022 [Member]      
Revenue, Performance Obligation [Abstract]      
Fixed Performance Obligations 0.0    
AEP Transmission Co [Member] | 2023-2024 [Member]      
Revenue, Performance Obligation [Abstract]      
Fixed Performance Obligations 0.0    
AEP Transmission Co [Member] | 2024 and Forward [Member]      
Revenue, Performance Obligation [Abstract]      
Fixed Performance Obligations 0.0    
AEP Transmission Co [Member] | Retail [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 0.0 0.0  
AEP Transmission Co [Member] | Residential [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 0.0 0.0  
AEP Transmission Co [Member] | Commercial [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 0.0 0.0  
AEP Transmission Co [Member] | Industrial [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 0.0 0.0  
AEP Transmission Co [Member] | Other Retail [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 0.0 0.0  
AEP Transmission Co [Member] | Wholesale and Competitive [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 298.2 242.1  
AEP Transmission Co [Member] | Generation [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 0.0 [7] 0.0 [8]  
AEP Transmission Co [Member] | Transmission [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 298.2 [9] 242.1 [10]  
Revenue Textuals [Abstract]      
Revenue from Related Parties 235.0 195.0  
AEP Transmission Co [Member] | Other Revenues [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 3.4 [11] 3.1 [12]  
AEP Transmission Co [Member] | Affiliated and Nonaffiliated [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 301.6 245.2  
AEP Transmission Co [Member] | Alternative [Member]      
Disaggregation of Revenue [Abstract]      
Revenue Not from Contract with Customer, Other (6.0) [13] (1.7) [14]  
AEP Transmission Co [Member] | Other Revenues [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 0.6 0.0  
Revenue Not from Contract with Customer, Other 0.0 [13] 0.0 [14]  
Appalachian Power Co [Member]      
Disaggregation of Revenue [Abstract]      
Revenue Not from Contract with Customer, Other (1.1) 4.4  
Total Revenues 749.4 792.8  
Revenue, Performance Obligation [Abstract]      
Fixed Performance Obligations 186.9    
Assets, Current [Abstract]      
Affiliated Companies - Contracts with Customers 78.0   64.3
Revenue Textuals [Abstract]      
Revenue from Related Parties 49.7 51.7  
Appalachian Power Co [Member] | Short-term Contract with Customer [Member]      
Assets, Current [Abstract]      
Affiliated Companies - Contracts with Customers 56.3   47.3
Appalachian Power Co [Member] | 2020 [Member]      
Revenue, Performance Obligation [Abstract]      
Fixed Performance Obligations 118.6    
Appalachian Power Co [Member] | 2021-2022 [Member]      
Revenue, Performance Obligation [Abstract]      
Fixed Performance Obligations 32.3    
Appalachian Power Co [Member] | 2023-2024 [Member]      
Revenue, Performance Obligation [Abstract]      
Fixed Performance Obligations 24.4    
Appalachian Power Co [Member] | 2024 and Forward [Member]      
Revenue, Performance Obligation [Abstract]      
Fixed Performance Obligations 11.6    
Appalachian Power Co [Member] | Retail [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 648.8 681.8  
Appalachian Power Co [Member] | Residential [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 357.5 372.5  
Appalachian Power Co [Member] | Commercial [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 132.3 142.2  
Appalachian Power Co [Member] | Industrial [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 141.1 147.5  
Appalachian Power Co [Member] | Other Retail [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 17.9 19.6  
Appalachian Power Co [Member] | Wholesale and Competitive [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 84.5 93.2  
Appalachian Power Co [Member] | Generation [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 54.1 [7] 67.5 [8]  
Revenue Textuals [Abstract]      
Revenue from Related Parties 33.0 35.0  
Appalachian Power Co [Member] | Transmission [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 30.4 [9] 25.7 [10]  
Appalachian Power Co [Member] | Other Revenues [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 17.2 [11] 13.4 [12]  
Appalachian Power Co [Member] | Affiliated and Nonaffiliated [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 750.5 788.4  
Appalachian Power Co [Member] | Alternative [Member]      
Disaggregation of Revenue [Abstract]      
Revenue Not from Contract with Customer, Other (1.1) [13] 4.4 [14]  
Appalachian Power Co [Member] | Other Revenues [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 2.7 2.4  
Revenue Not from Contract with Customer, Other 0.0 [13] 0.0 [14]  
Indiana Michigan Power Co [Member]      
Disaggregation of Revenue [Abstract]      
Revenue Not from Contract with Customer, Other 0.4 (4.8)  
Total Revenues 570.3 614.3  
Revenue, Performance Obligation [Abstract]      
Fixed Performance Obligations 44.2    
Assets, Current [Abstract]      
Affiliated Companies - Contracts with Customers 51.1   53.7
Revenue Textuals [Abstract]      
Revenue from Related Parties 2.9 2.3  
Indiana Michigan Power Co [Member] | Short-term Contract with Customer [Member]      
Assets, Current [Abstract]      
Affiliated Companies - Contracts with Customers 37.4   37.1
Indiana Michigan Power Co [Member] | 2020 [Member]      
Revenue, Performance Obligation [Abstract]      
Fixed Performance Obligations 22.2    
Indiana Michigan Power Co [Member] | 2021-2022 [Member]      
Revenue, Performance Obligation [Abstract]      
Fixed Performance Obligations 8.8    
Indiana Michigan Power Co [Member] | 2023-2024 [Member]      
Revenue, Performance Obligation [Abstract]      
Fixed Performance Obligations 8.8    
Indiana Michigan Power Co [Member] | 2024 and Forward [Member]      
Revenue, Performance Obligation [Abstract]      
Fixed Performance Obligations 4.4    
Indiana Michigan Power Co [Member] | Retail [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 463.1 479.9  
Indiana Michigan Power Co [Member] | Residential [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 201.3 218.4  
Indiana Michigan Power Co [Member] | Commercial [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 122.2 121.3  
Indiana Michigan Power Co [Member] | Industrial [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 137.8 138.4  
Indiana Michigan Power Co [Member] | Other Retail [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 1.8 1.8  
Indiana Michigan Power Co [Member] | Wholesale and Competitive [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 85.8 118.2  
Indiana Michigan Power Co [Member] | Generation [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 78.4 [7] 111.9 [8]  
Indiana Michigan Power Co [Member] | Transmission [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 7.4 [9] 6.3 [10]  
Indiana Michigan Power Co [Member] | Other Revenues [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 21.0 [11] 21.0 [12]  
Indiana Michigan Power Co [Member] | Affiliated and Nonaffiliated [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 569.9 619.1  
Indiana Michigan Power Co [Member] | Alternative [Member]      
Disaggregation of Revenue [Abstract]      
Revenue Not from Contract with Customer, Other 0.4 [13] (4.8) [14]  
Indiana Michigan Power Co [Member] | Other Revenues [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 1.5 2.0  
Revenue Not from Contract with Customer, Other 0.0 [13] 0.0 [14]  
Revenue Textuals [Abstract]      
Revenue from Related Parties 16.0 15.0  
Ohio Power Co [Member]      
Disaggregation of Revenue [Abstract]      
Revenue Not from Contract with Customer, Other 26.1 8.7  
Total Revenues 690.3 836.8  
Revenue, Performance Obligation [Abstract]      
Fixed Performance Obligations 43.2    
Assets, Current [Abstract]      
Affiliated Companies - Contracts with Customers 73.1   59.3
Revenue Textuals [Abstract]      
Revenue from Related Parties 8.4 7.5  
Ohio Power Co [Member] | Short-term Contract with Customer [Member]      
Assets, Current [Abstract]      
Affiliated Companies - Contracts with Customers 39.3   33.9
Ohio Power Co [Member] | 2020 [Member]      
Revenue, Performance Obligation [Abstract]      
Fixed Performance Obligations 43.2    
Ohio Power Co [Member] | 2021-2022 [Member]      
Revenue, Performance Obligation [Abstract]      
Fixed Performance Obligations 0.0    
Ohio Power Co [Member] | 2023-2024 [Member]      
Revenue, Performance Obligation [Abstract]      
Fixed Performance Obligations 0.0    
Ohio Power Co [Member] | 2024 and Forward [Member]      
Revenue, Performance Obligation [Abstract]      
Fixed Performance Obligations 0.0    
Ohio Power Co [Member] | Retail [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 618.5 775.2  
Ohio Power Co [Member] | Residential [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 388.4 471.6  
Ohio Power Co [Member] | Commercial [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 164.0 210.5  
Ohio Power Co [Member] | Industrial [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 62.7 89.7  
Ohio Power Co [Member] | Other Retail [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 3.4 3.4  
Ohio Power Co [Member] | Wholesale and Competitive [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 17.1 13.9  
Ohio Power Co [Member] | Generation [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 0.0 [7] 0.0 [8]  
Ohio Power Co [Member] | Transmission [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 17.1 [9] 13.9 [10]  
Ohio Power Co [Member] | Other Revenues [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 28.6 [11] 39.0 [12]  
Ohio Power Co [Member] | Affiliated and Nonaffiliated [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 664.2 828.1  
Ohio Power Co [Member] | Alternative [Member]      
Disaggregation of Revenue [Abstract]      
Revenue Not from Contract with Customer, Other 20.0 [13] 3.6 [14]  
Ohio Power Co [Member] | Other Revenues [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 2.7 2.8  
Revenue Not from Contract with Customer, Other 6.1 [13] 5.1 [14]  
Public Service Co Of Oklahoma [Member]      
Disaggregation of Revenue [Abstract]      
Revenue Not from Contract with Customer, Other 0.4 (1.2)  
Total Revenues 297.3 332.8  
Revenue, Performance Obligation [Abstract]      
Fixed Performance Obligations 10.8    
Assets, Current [Abstract]      
Affiliated Companies - Contracts with Customers 19.9   20.6
Revenue Textuals [Abstract]      
Revenue from Related Parties 1.1 1.6  
Public Service Co Of Oklahoma [Member] | Short-term Contract with Customer [Member]      
Assets, Current [Abstract]      
Affiliated Companies - Contracts with Customers 6.2   9.7
Public Service Co Of Oklahoma [Member] | 2020 [Member]      
Revenue, Performance Obligation [Abstract]      
Fixed Performance Obligations 10.8    
Public Service Co Of Oklahoma [Member] | 2021-2022 [Member]      
Revenue, Performance Obligation [Abstract]      
Fixed Performance Obligations 0.0    
Public Service Co Of Oklahoma [Member] | 2023-2024 [Member]      
Revenue, Performance Obligation [Abstract]      
Fixed Performance Obligations 0.0    
Public Service Co Of Oklahoma [Member] | 2024 and Forward [Member]      
Revenue, Performance Obligation [Abstract]      
Fixed Performance Obligations 0.0    
Public Service Co Of Oklahoma [Member] | Retail [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 282.5 309.8  
Public Service Co Of Oklahoma [Member] | Residential [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 128.5 140.0  
Public Service Co Of Oklahoma [Member] | Commercial [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 76.1 80.8  
Public Service Co Of Oklahoma [Member] | Industrial [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 61.3 71.0  
Public Service Co Of Oklahoma [Member] | Other Retail [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 16.6 18.0  
Public Service Co Of Oklahoma [Member] | Wholesale and Competitive [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 9.7 18.4  
Public Service Co Of Oklahoma [Member] | Generation [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 1.9 [7] 8.6 [8]  
Public Service Co Of Oklahoma [Member] | Transmission [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 7.8 [9] 9.8 [10]  
Public Service Co Of Oklahoma [Member] | Other Revenues [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 4.7 [11] 5.8 [12]  
Public Service Co Of Oklahoma [Member] | Affiliated and Nonaffiliated [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 296.9 334.0  
Public Service Co Of Oklahoma [Member] | Alternative [Member]      
Disaggregation of Revenue [Abstract]      
Revenue Not from Contract with Customer, Other 0.4 [13] (1.2) [14]  
Public Service Co Of Oklahoma [Member] | Other Revenues [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 0.8 2.0  
Revenue Not from Contract with Customer, Other 0.0 [13] 0.0 [14]  
Southwestern Electric Power Co [Member]      
Disaggregation of Revenue [Abstract]      
Revenue Not from Contract with Customer, Other 1.6 (5.3)  
Total Revenues 385.9 421.1  
Revenue, Performance Obligation [Abstract]      
Fixed Performance Obligations 29.6    
Assets, Current [Abstract]      
Affiliated Companies - Contracts with Customers 24.4   34.5
Revenue Textuals [Abstract]      
Revenue from Related Parties 7.5 6.4  
Southwestern Electric Power Co [Member] | Short-term Contract with Customer [Member]      
Assets, Current [Abstract]      
Affiliated Companies - Contracts with Customers 11.0   $ 17.6
Southwestern Electric Power Co [Member] | 2020 [Member]      
Revenue, Performance Obligation [Abstract]      
Fixed Performance Obligations 29.6    
Southwestern Electric Power Co [Member] | 2021-2022 [Member]      
Revenue, Performance Obligation [Abstract]      
Fixed Performance Obligations 0.0    
Southwestern Electric Power Co [Member] | 2023-2024 [Member]      
Revenue, Performance Obligation [Abstract]      
Fixed Performance Obligations 0.0    
Southwestern Electric Power Co [Member] | 2024 and Forward [Member]      
Revenue, Performance Obligation [Abstract]      
Fixed Performance Obligations 0.0    
Southwestern Electric Power Co [Member] | Retail [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 319.0 337.2  
Southwestern Electric Power Co [Member] | Residential [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 131.6 140.1  
Southwestern Electric Power Co [Member] | Commercial [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 105.6 113.7  
Southwestern Electric Power Co [Member] | Industrial [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 79.8 81.2  
Southwestern Electric Power Co [Member] | Other Retail [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 2.0 2.2  
Southwestern Electric Power Co [Member] | Wholesale and Competitive [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 59.5 81.4  
Southwestern Electric Power Co [Member] | Generation [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 34.1 [7] 57.2 [8]  
Southwestern Electric Power Co [Member] | Transmission [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 25.4 [9] 24.2 [10]  
Southwestern Electric Power Co [Member] | Other Revenues [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 5.8 [11] 7.8 [12]  
Southwestern Electric Power Co [Member] | Affiliated and Nonaffiliated [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 384.3 426.4  
Southwestern Electric Power Co [Member] | Alternative [Member]      
Disaggregation of Revenue [Abstract]      
Revenue Not from Contract with Customer, Other 1.6 [13] (5.3) [14]  
Southwestern Electric Power Co [Member] | Other Revenues [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 0.8 0.4  
Revenue Not from Contract with Customer, Other 0.0 [13] 0.0 [14]  
Consolidation Eliminations [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 0.0 0.0  
Revenue Not from Contract with Customer, Other (21.0) (39.7)  
Total Revenues (354.8) (332.2)  
Revenue Textuals [Abstract]      
Revenue from Related Parties (354.8) (332.2)  
Consolidation Eliminations [Member] | Retail [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers (0.2) 1.8  
Consolidation Eliminations [Member] | Residential [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 0.0 0.0  
Consolidation Eliminations [Member] | Commercial [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 0.0 0.0  
Consolidation Eliminations [Member] | Industrial [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers (0.2) 1.8  
Consolidation Eliminations [Member] | Other Retail [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 0.0 0.0  
Consolidation Eliminations [Member] | Wholesale and Competitive [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers (293.0) (258.2)  
Consolidation Eliminations [Member] | Generation [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 0.0 (38.8)  
Consolidation Eliminations [Member] | Transmission [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers (263.0) [1] (219.4) [2]  
Consolidation Eliminations [Member] | Renewable Generation [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers (0.6) [3] 0.0 [4]  
Consolidation Eliminations [Member] | Retail, Trading and Marketing Revenues [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers (29.4) [5] 0.0 [6]  
Consolidation Eliminations [Member] | Other Revenues [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers (40.6) [3] (36.1) [4]  
Consolidation Eliminations [Member] | Affiliated and Nonaffiliated [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers (333.8) (292.5)  
Consolidation Eliminations [Member] | Alternative [Member]      
Disaggregation of Revenue [Abstract]      
Revenue Not from Contract with Customer, Other 4.5 [3] 0.0 [4]  
Consolidation Eliminations [Member] | Other Revenues [Member]      
Disaggregation of Revenue [Abstract]      
Revenue Not from Contract with Customer, Other (25.5) [3] (39.7) [4]  
Consolidation Eliminations [Member] | AEP Transmission Co [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 0.0 0.0  
Total Revenues 0.0 0.0  
Revenue Textuals [Abstract]      
Revenue from Related Parties 0.0 0.0  
Consolidation Eliminations [Member] | AEP Transmission Co [Member] | Other Revenues [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 0.0    
Vertically Integrated Utilities [Member]      
Disaggregation of Revenue [Abstract]      
Revenue Not from Contract with Customer, Other 0.2 (3.4)  
Total Revenues 2,226.7 2,403.3  
Revenue Textuals [Abstract]      
Revenue from Related Parties 33.7 31.0  
Vertically Integrated Utilities [Member] | Retail [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 1,962.6 2,069.0  
Vertically Integrated Utilities [Member] | Residential [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 915.1 982.4  
Vertically Integrated Utilities [Member] | Commercial [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 489.4 511.2  
Vertically Integrated Utilities [Member] | Industrial [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 518.2 532.1  
Vertically Integrated Utilities [Member] | Other Retail [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 39.9 43.3  
Vertically Integrated Utilities [Member] | Wholesale and Competitive [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 220.3 298.2  
Vertically Integrated Utilities [Member] | Generation [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 140.4 224.7  
Vertically Integrated Utilities [Member] | Transmission [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 79.9 [1] 73.5 [2]  
Vertically Integrated Utilities [Member] | Renewable Generation [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 0.0 [3] 0.0 [4]  
Vertically Integrated Utilities [Member] | Retail, Trading and Marketing Revenues [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 0.0 [5] 0.0 [6]  
Vertically Integrated Utilities [Member] | Other Revenues [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 43.6 [3] 39.5 [4]  
Vertically Integrated Utilities [Member] | Affiliated and Nonaffiliated [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 2,226.5 2,406.7  
Vertically Integrated Utilities [Member] | Alternative [Member]      
Disaggregation of Revenue [Abstract]      
Revenue Not from Contract with Customer, Other 0.2 [3] (3.4) [4]  
Vertically Integrated Utilities [Member] | Other Revenues [Member]      
Disaggregation of Revenue [Abstract]      
Revenue Not from Contract with Customer, Other 0.0 [3] 0.0 [4]  
Transmission And Distribution Utilities [Member]      
Disaggregation of Revenue [Abstract]      
Revenue Not from Contract with Customer, Other 48.6 44.4  
Total Revenues 1,106.9 1,222.0  
Revenue Textuals [Abstract]      
Revenue from Related Parties 31.7 42.2  
Transmission And Distribution Utilities [Member] | Retail [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 907.8 1,032.0  
Transmission And Distribution Utilities [Member] | Residential [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 521.3 586.1  
Transmission And Distribution Utilities [Member] | Commercial [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 276.9 310.9  
Transmission And Distribution Utilities [Member] | Industrial [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 97.8 123.9  
Transmission And Distribution Utilities [Member] | Other Retail [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 11.8 11.1  
Transmission And Distribution Utilities [Member] | Wholesale and Competitive [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 114.1 99.6  
Transmission And Distribution Utilities [Member] | Generation [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 0.0 0.0  
Transmission And Distribution Utilities [Member] | Transmission [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 114.1 [1] 99.6 [2]  
Transmission And Distribution Utilities [Member] | Renewable Generation [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 0.0 [3] 0.0 [4]  
Transmission And Distribution Utilities [Member] | Retail, Trading and Marketing Revenues [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 0.0 [5] 0.0 [6]  
Transmission And Distribution Utilities [Member] | Other Revenues [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 36.4 [3] 46.0 [4]  
Transmission And Distribution Utilities [Member] | Affiliated and Nonaffiliated [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 1,058.3 1,177.6  
Transmission And Distribution Utilities [Member] | Alternative [Member]      
Disaggregation of Revenue [Abstract]      
Revenue Not from Contract with Customer, Other 19.3 [3] 5.0 [4]  
Transmission And Distribution Utilities [Member] | Other Revenues [Member]      
Disaggregation of Revenue [Abstract]      
Revenue Not from Contract with Customer, Other 29.3 [3] 39.4 [4]  
AEP Transmission Holdco [Member]      
Disaggregation of Revenue [Abstract]      
Revenue Not from Contract with Customer, Other (3.3) (1.8)  
Total Revenues 310.2 256.4  
AEP Transmission Holdco [Member] | Retail [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 0.0 0.0  
AEP Transmission Holdco [Member] | Residential [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 0.0 0.0  
AEP Transmission Holdco [Member] | Commercial [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 0.0 0.0  
AEP Transmission Holdco [Member] | Industrial [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 0.0 0.0  
AEP Transmission Holdco [Member] | Other Retail [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 0.0 0.0  
AEP Transmission Holdco [Member] | Wholesale and Competitive [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 309.8 255.1  
AEP Transmission Holdco [Member] | Generation [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 0.0 0.0  
AEP Transmission Holdco [Member] | Transmission [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 309.8 [1] 255.1 [2]  
Revenue Textuals [Abstract]      
Revenue from Related Parties 239.0 198.0  
AEP Transmission Holdco [Member] | Renewable Generation [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 0.0 [3] 0.0 [4]  
AEP Transmission Holdco [Member] | Retail, Trading and Marketing Revenues [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 0.0 [5] 0.0 [6]  
AEP Transmission Holdco [Member] | Other Revenues [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 3.7 [3] 3.1 [4]  
AEP Transmission Holdco [Member] | Affiliated and Nonaffiliated [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 313.5 258.2  
AEP Transmission Holdco [Member] | Alternative [Member]      
Disaggregation of Revenue [Abstract]      
Revenue Not from Contract with Customer, Other (3.3) [3] (1.8) [4]  
AEP Transmission Holdco [Member] | Other Revenues [Member]      
Disaggregation of Revenue [Abstract]      
Revenue Not from Contract with Customer, Other 0.0 [3] 0.0 [4]  
Generation And Marketing [Member]      
Disaggregation of Revenue [Abstract]      
Revenue Not from Contract with Customer, Other 18.3 9.2  
Total Revenues 438.6 481.8  
Revenue Textuals [Abstract]      
Revenue from Related Parties 30.2 42.1  
Generation And Marketing [Member] | Retail [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 0.0 0.0  
Generation And Marketing [Member] | Residential [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 0.0 0.0  
Generation And Marketing [Member] | Commercial [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 0.0 0.0  
Generation And Marketing [Member] | Industrial [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 0.0 0.0  
Generation And Marketing [Member] | Other Retail [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 0.0 0.0  
Generation And Marketing [Member] | Wholesale and Competitive [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 420.0 470.3  
Generation And Marketing [Member] | Generation [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 44.1 108.8  
Generation And Marketing [Member] | Transmission [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 0.0 [1] 0.0 [2]  
Generation And Marketing [Member] | Wholesale Generation [Member]      
Revenue Textuals [Abstract]      
Revenue from Related Parties 35.0 37.0  
Generation And Marketing [Member] | Renewable Generation [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 17.2 [3] 7.8 [4]  
Generation And Marketing [Member] | Retail, Trading and Marketing Revenues [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 358.7 [5] 353.7 [6]  
Generation And Marketing [Member] | Other Revenues [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 0.3 [3] 2.3 [4]  
Generation And Marketing [Member] | Affiliated and Nonaffiliated [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 420.3 472.6  
Generation And Marketing [Member] | Alternative [Member]      
Disaggregation of Revenue [Abstract]      
Revenue Not from Contract with Customer, Other 0.0 [3] 0.0 [4]  
Generation And Marketing [Member] | Other Revenues [Member]      
Disaggregation of Revenue [Abstract]      
Revenue Not from Contract with Customer, Other 18.3 [3] 9.2 [4]  
Other Segments [Member]      
Disaggregation of Revenue [Abstract]      
Revenue Not from Contract with Customer, Other (2.2) 2.2  
Total Revenues [15] 19.9 25.5  
Revenue Textuals [Abstract]      
Revenue from Related Parties [15] 22.1 21.7  
Other Segments [Member] | Retail [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 0.0 0.0  
Other Segments [Member] | Residential [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 0.0 0.0  
Other Segments [Member] | Commercial [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 0.0 0.0  
Other Segments [Member] | Industrial [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 0.0 0.0  
Other Segments [Member] | Other Retail [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 0.0 0.0  
Other Segments [Member] | Wholesale and Competitive [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers (6.0) 0.0  
Other Segments [Member] | Generation [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 0.0 0.0  
Other Segments [Member] | Transmission [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 0.0 [1] 0.0 [2]  
Other Segments [Member] | Renewable Generation [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 0.0 [3] 0.0 [4]  
Other Segments [Member] | Retail, Trading and Marketing Revenues [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers (6.0) [5] 0.0 [6]  
Other Segments [Member] | Other Revenues [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 28.1 [3] 23.3 [4]  
Other Segments [Member] | Affiliated and Nonaffiliated [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers 22.1 23.3  
Other Segments [Member] | Alternative [Member]      
Disaggregation of Revenue [Abstract]      
Revenue Not from Contract with Customer, Other 0.0 [3] 0.0 [4]  
Other Segments [Member] | Other Revenues [Member]      
Disaggregation of Revenue [Abstract]      
Revenue from Contracts with Customers [15] (2.2) 3.8  
Revenue Not from Contract with Customer, Other $ (2.2) [3] $ 2.2 [4]  
[1]
Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for AEP Transmission Holdco was $239 million. The remaining affiliated amounts were immaterial.
[2]
Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for AEP Transmission Holdco was $198 million. The remaining affiliated amounts were immaterial.
[3]
Amounts include affiliated and nonaffiliated revenues.
[4]
Amounts include affiliated and nonaffiliated revenues.
[5]
Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for Generation & Marketing was $35 million. The remaining affiliated amounts were immaterial.
[6]
Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for Generation & Marketing was $37 million. The remaining affiliated amounts were immaterial.
[7]
Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for APCo was $33 million primarily relating to the PPA with KGPCo. The remaining affiliated amounts were immaterial.
[8]
Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for APCo was $35 million primarily relating to the PPA with KGPCo. The remaining affiliated amounts were immaterial.
[9]
Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for AEPTCo was $235 million. The remaining affiliated amounts were immaterial.
[10]
Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for AEPTCo was $195 million. The remaining affiliated amounts were immaterial.
[11]
Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for I&M was $16 million primarily relating to the barging, urea transloading and other transportation services. The remaining affiliated amounts were immaterial.
[12]
Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for I&M was $15 million primarily relating to the barging, urea transloading and other transportation services. The remaining affiliated amounts were immaterial.
[13]
Amounts include affiliated and nonaffiliated revenues.
[14]
Amounts include affiliated and nonaffiliated revenues.
[15]
Corporate and Other primarily includes the purchasing of receivables from certain AEP utility subsidiaries. This segment also includes Parent’s guarantee revenue received from affiliates, investment income, interest income, interest expense and other nonallocated costs.