v3.24.0.1
Acquisitions, Dispositions and Impairments (Details)
 3 Months Ended 12 Months Ended
Sep. 30, 2022
USD ($)
Jun. 30, 2022
USD ($)
Dec. 31, 2023
USD ($)
MW
Dec. 31, 2022
USD ($)
Dec. 31, 2021
USD ($)
Mar. 31, 2023
USD ($)
Asset Impairments and Other Related Charges     $ 85,600,000 $ 48,800,000 $ 11,600,000  
Utilities Operating Expense, Operations     2,810,500,000 2,878,100,000 2,547,700,000  
Additional Paid in Capital     9,073,900,000 8,051,000,000    
Asset Retirement Obligation, Liabilities Settled [1],[2],[3],[4],[5],[6]     130,600,000 47,000,000.0    
Property, Plant and Equipment, Generation     24,329,500,000 25,834,200,000    
Obligations Under Operating Leases     519,400,000 552,500,000    
Customers     1,029,900,000 1,145,100,000    
Materials and Supplies     1,025,800,000 915,100,000    
Net Investment     76,693,400,000 73,339,100,000    
Noncurrent Regulatory Assets     5,092,400,000 4,762,000,000    
Accounts Payable - Affiliated Companies for collected reclamation costs that have been billed to SWEPCo     2,032,500,000 2,670,800,000    
Long-term Debt, Current Maturities     2,490,500,000 2,486,400,000    
Customer Deposits, Current     423,700,000 408,800,000    
Regulatory Liabilities and Deferred Investment Tax Credits     8,182,400,000 8,115,600,000    
Long-term Debt, Excluding Current Maturities     37,652,700,000 34,314,600,000    
Property, Plant and Equipment, Other     6,484,900,000 5,971,800,000    
Depreciation and Amortization of Property, Plant and Equipment     2,927,500,000 3,072,800,000 2,717,100,000  
Equity Method Investment, Other than Temporary Impairment     $ 19,000,000.0 188,000,000.0 0  
Equity Method Investment, Ownership Percentage     50.00%      
Deferred Tax Assets     $ 3,216,100,000 3,567,400,000    
Disposal Group, Including Discontinued Operation, Income Statement Disclosures            
Proceeds from Sale of Property, Plant, and Equipment     (1,341,400,000) (218,000,000.0) 118,900,000  
Kentucky Operations [Member]            
Asset Impairments and Other Related Charges     0 363,300,000 0  
Vertically Integrated Utilities [Member]            
Asset Impairments and Other Related Charges     85,600,000 24,900,000 11,600,000  
Disposal Group, Including Discontinued Operation, Income Statement Disclosures            
Enterprise Value       2,850,000,000    
Pretax Reduction in Investment Basis     $ 335,000,000      
Business Acquisition, Transaction Costs           $ 28,000,000
Vertically Integrated Utilities [Member] | Proceeds for KY Operations            
Disposal Group, Including Discontinued Operation, Income Statement Disclosures            
Enterprise Value       2,646,000,000    
Vertically Integrated Utilities [Member] | Sundance [Member]            
WindGenerationMWs | MW     199      
Vertically Integrated Utilities [Member] | Maverick [Member]            
WindGenerationMWs | MW     287      
Vertically Integrated Utilities [Member] | Traverse [Member]            
WindGenerationMWs | MW     998      
Vertically Integrated Utilities [Member] | North Central Wind Energy Facilities | Maverick [Member]            
Payments to Acquire Property, Plant, and Equipment         383,000,000  
Vertically Integrated Utilities [Member] | North Central Wind Energy Facilities | Traverse [Member]            
Payments to Acquire Property, Plant, and Equipment       1,200,000,000    
Generation and Marketing [Member]            
Asset Impairments and Other Related Charges     $ 0 0 0  
Generation and Marketing [Member] | BP Wind Energy [Member]            
Equity Method Investment, Other than Temporary Impairment $ 2,000,000 $ 186,000,000        
Equity Method Investment, Ownership Percentage     50.00%      
Generation and Marketing [Member] | New Mexico Renewable Development [Member]            
Equity Method Investment, Other than Temporary Impairment     $ 19,000,000      
Generation and Marketing [Member] | Proceeds of Mineral Rights Sale            
Disposal Group, Including Discontinued Operation, Income Statement Disclosures            
Proceeds from Sale of Property, Plant, and Equipment       120,000,000    
Gain (Loss) on Disposition of Other Assets       116,000,000    
Generation and Marketing [Member] | Dry Lake Solar Project [Member]            
Payments to Acquire Property, Plant, and Equipment         114,000,000  
Transmission and Distribution Companies [Member]            
Asset Impairments and Other Related Charges     0 0 0  
AEP Transmission Holdco            
Asset Impairments and Other Related Charges     0 0 0  
Disposal Group, Including Discontinued Operation, Income Statement Disclosures            
Enterprise Value       2,850,000,000    
Pretax Reduction in Investment Basis     335,000,000      
AEP Transmission Holdco | Proceeds for KY Operations            
Disposal Group, Including Discontinued Operation, Income Statement Disclosures            
Enterprise Value       2,646,000,000    
AEP Texas Inc. [Member]            
Utilities Operating Expense, Operations     541,600,000 594,200,000 489,500,000  
Additional Paid in Capital     2,079,600,000 1,558,200,000    
Asset Retirement Obligation, Liabilities Settled [3],[4]     300,000 200,000    
Obligations Under Operating Leases     50,900,000 67,800,000    
Customers     176,500,000 150,900,000    
Materials and Supplies     190,400,000 138,800,000    
Net Investment     12,774,000,000 11,681,600,000    
Noncurrent Regulatory Assets     315,300,000 298,300,000    
Accounts Payable - Affiliated Companies for collected reclamation costs that have been billed to SWEPCo     192,300,000 331,000,000.0    
Long-term Debt, Current Maturities     96,000,000.0 278,500,000    
Regulatory Liabilities and Deferred Investment Tax Credits     1,261,400,000 1,259,600,000    
Long-term Debt, Excluding Current Maturities     5,793,800,000 5,379,300,000    
Property, Plant and Equipment, Other     1,145,900,000 1,022,800,000    
Depreciation and Amortization of Property, Plant and Equipment     380,000,000.0 363,500,000 327,200,000  
Deferred Tax Assets     173,600,000 177,000,000.0    
AEP Transmission Co [Member]            
Utilities Operating Expense, Operations     109,000,000.0 136,300,000 105,500,000  
Payments to Acquire Property, Plant, and Equipment     6,900,000 9,800,000 17,900,000  
Obligations Under Operating Leases     1,400,000 1,500,000    
Customers     82,200,000 46,900,000    
Materials and Supplies     0 10,700,000    
Net Investment     14,497,700,000 13,339,900,000    
Noncurrent Regulatory Assets     3,100,000 7,200,000    
Accounts Payable - Affiliated Companies for collected reclamation costs that have been billed to SWEPCo     274,700,000 427,800,000    
Long-term Debt, Current Maturities     95,000,000.0 60,000,000.0    
Regulatory Liabilities and Deferred Investment Tax Credits     783,700,000 723,300,000    
Long-term Debt, Excluding Current Maturities     5,319,400,000 4,722,800,000    
Property, Plant and Equipment, Other     501,400,000 476,800,000    
Depreciation and Amortization of Property, Plant and Equipment     393,800,000 346,200,000 297,300,000  
Deferred Tax Assets     188,100,000 165,000,000.0    
Appalachian Power Co [Member]            
Asset Impairments and Other Related Charges     0 24,900,000 0  
Utilities Operating Expense, Operations     748,400,000 724,100,000 610,000,000.0  
Additional Paid in Capital     1,834,500,000 1,828,700,000    
Asset Retirement Obligation, Liabilities Settled [3],[4]     23,100,000 12,700,000    
Property, Plant and Equipment, Generation     7,041,300,000 6,776,800,000    
Obligations Under Operating Leases     59,800,000 59,100,000    
Customers     170,300,000 168,900,000    
Materials and Supplies     148,400,000 130,600,000    
Net Investment     12,931,500,000 12,379,200,000    
Noncurrent Regulatory Assets     1,155,100,000 1,058,600,000    
Accounts Payable - Affiliated Companies for collected reclamation costs that have been billed to SWEPCo     280,400,000 451,200,000    
Long-term Debt, Current Maturities     538,800,000 251,800,000    
Customer Deposits, Current     80,000,000.0 75,100,000    
Regulatory Liabilities and Deferred Investment Tax Credits     1,081,900,000 1,143,600,000    
Long-term Debt, Excluding Current Maturities     5,049,500,000 5,158,700,000    
Property, Plant and Equipment, Other     981,300,000 883,300,000    
Depreciation and Amortization of Property, Plant and Equipment     571,100,000 576,100,000 547,000,000.0  
Deferred Tax Assets     473,000,000.0 510,300,000    
Indiana Michigan Power Co [Member]            
Utilities Operating Expense, Operations     662,800,000 621,000,000.0 645,200,000  
Additional Paid in Capital     997,600,000 988,800,000    
Asset Retirement Obligation, Liabilities Settled [3],[4],[5]     3,700,000 600,000    
Property, Plant and Equipment, Generation     5,646,800,000 5,585,100,000    
Obligations Under Operating Leases     37,700,000 48,900,000    
Customers     66,900,000 96,600,000    
Materials and Supplies     208,200,000 188,100,000    
Net Investment     7,629,000,000 7,411,500,000    
Noncurrent Regulatory Assets     406,300,000 459,600,000    
Accounts Payable - Affiliated Companies for collected reclamation costs that have been billed to SWEPCo     225,800,000 173,400,000    
Long-term Debt, Current Maturities     83,700,000 341,800,000    
Customer Deposits, Current     72,200,000 48,600,000    
Regulatory Liabilities and Deferred Investment Tax Credits     2,052,300,000 1,702,200,000    
Long-term Debt, Excluding Current Maturities     3,415,700,000 2,919,000,000    
Property, Plant and Equipment, Other     898,500,000 839,300,000    
Depreciation and Amortization of Property, Plant and Equipment     439,800,000 511,900,000 424,900,000  
Deferred Tax Assets     1,014,100,000 933,700,000    
Ohio Power Co [Member]            
Cost of Purchased Power from Affiliate     86,800,000 9,800,000 51,900,000  
Utilities Operating Expense, Operations     1,091,700,000 982,000,000.0 836,800,000  
Additional Paid in Capital     1,012,800,000 837,800,000    
Asset Retirement Obligation, Liabilities Settled [4]     3,100,000 100,000    
Obligations Under Operating Leases     56,700,000 60,300,000    
Customers     39,200,000 119,900,000    
Materials and Supplies     175,000,000.0 109,500,000    
Net Investment     9,299,900,000 8,609,300,000    
Noncurrent Regulatory Assets     455,000,000.0 327,300,000    
Accounts Payable - Affiliated Companies for collected reclamation costs that have been billed to SWEPCo     320,700,000 337,300,000    
Long-term Debt, Current Maturities     0 100,000    
Customer Deposits, Current     62,000,000.0 96,500,000    
Regulatory Liabilities and Deferred Investment Tax Credits     1,003,600,000 1,044,000,000    
Long-term Debt, Excluding Current Maturities     3,366,800,000 2,970,200,000    
Property, Plant and Equipment, Other     1,125,000,000 1,051,400,000    
Depreciation and Amortization of Property, Plant and Equipment     315,800,000 293,100,000 301,100,000  
Deferred Tax Assets     271,400,000 218,800,000    
Public Service Co Of Oklahoma [Member]            
Utilities Operating Expense, Operations     355,800,000 400,400,000 353,800,000  
Additional Paid in Capital     1,039,300,000 1,042,600,000    
Asset Retirement Obligation, Liabilities Settled [1],[3],[4]     1,200,000 700,000    
Property, Plant and Equipment, Generation     2,695,500,000 2,394,800,000    
Obligations Under Operating Leases     106,800,000 99,300,000    
Customers     107,600,000 70,100,000    
Materials and Supplies     106,900,000 111,100,000    
Net Investment     6,112,300,000 5,626,500,000    
Noncurrent Regulatory Assets     522,700,000 653,700,000    
Accounts Payable - Affiliated Companies for collected reclamation costs that have been billed to SWEPCo     159,300,000 202,900,000    
Long-term Debt, Current Maturities     600,000 500,000    
Customer Deposits, Current     81,400,000 59,000,000.0    
Regulatory Liabilities and Deferred Investment Tax Credits     765,600,000 809,100,000    
Long-term Debt, Excluding Current Maturities     2,384,000,000 1,912,300,000    
Property, Plant and Equipment, Other     505,900,000 469,300,000    
Depreciation and Amortization of Property, Plant and Equipment     240,300,000 226,200,000 185,900,000  
Deferred Tax Assets     282,300,000 225,000,000.0    
Southwestern Electric Power Co [Member]            
Asset Impairments and Other Related Charges     85,600,000 0 11,600,000  
Utilities Operating Expense, Operations     360,500,000 424,700,000 360,300,000  
Additional Paid in Capital     1,492,200,000 1,442,200,000    
Asset Retirement Obligation, Liabilities Settled [1],[2],[3],[4]     55,000,000.0 25,800,000    
Property, Plant and Equipment, Generation     4,790,700,000 5,476,200,000    
Obligations Under Operating Leases     122,500,000 120,200,000    
Customers     39,000,000.0 38,800,000    
Materials and Supplies     88,400,000 92,100,000    
Net Investment     8,558,400,000 8,262,200,000    
Noncurrent Regulatory Assets     1,131,800,000 1,042,400,000    
Accounts Payable - Affiliated Companies for collected reclamation costs that have been billed to SWEPCo     198,900,000 213,100,000    
Long-term Debt, Current Maturities     0 6,200,000    
Customer Deposits, Current     72,500,000 65,400,000    
Regulatory Liabilities and Deferred Investment Tax Credits     756,100,000 825,700,000    
Long-term Debt, Excluding Current Maturities     3,646,900,000 3,385,400,000    
Property, Plant and Equipment, Other     814,400,000 804,400,000    
Depreciation and Amortization of Property, Plant and Equipment     323,400,000 319,300,000 292,900,000  
Deferred Tax Assets     441,500,000 374,900,000    
Southwestern Electric Power Co [Member] | North Central Wind Energy Facilities            
Payments to Acquire Property, Plant, and Equipment     0 658,000,000.0 355,800,000  
Southwestern Electric Power Co [Member] | Vertically Integrated Utilities [Member] | Turk Generating Plant [Member]            
Asset Impairments and Other Related Charges     86,000,000      
Southwestern Electric Power Co [Member] | Vertically Integrated Utilities [Member] | Dolet Hills Power Station [Member]            
Asset Impairments and Other Related Charges       12,000,000    
AEP Wind Holdings LLC [Member] | Indiana Michigan Power Co [Member] | Generation and Marketing [Member]            
Cost of Purchased Power from Affiliate     8,000,000.0 11,800,000 9,900,000  
AEP Wind Holdings LLC [Member] | Ohio Power Co [Member] | Generation and Marketing [Member]            
Cost of Purchased Power from Affiliate     16,100,000 23,600,000 19,600,000  
AEP Wind Holdings LLC [Member] | Southwestern Electric Power Co [Member] | Generation and Marketing [Member]            
Cost of Purchased Power from Affiliate     $ 0 13,700,000 14,500,000  
Dry Lake Solar Project [Member]            
Noncash or Part Noncash Acquisition, Other Assets Acquired         18,900,000  
Dry Lake Solar Project [Member] | Noncontrolling Interests [Member]            
Noncash or Part Noncash Acquisition, Other Assets Acquired         18,900,000  
Dry Lake Solar Project [Member] | Generation and Marketing [Member]            
Percentage of an Asset Acquired     75.00%      
North Central Wind Energy Facilities | Vertically Integrated Utilities [Member]            
WindGenerationMWs | MW     1,484      
Payments to Acquire Property, Plant, and Equipment     $ 2,000,000,000      
North Central Wind Energy Facilities | Vertically Integrated Utilities [Member] | Sundance [Member]            
Payments to Acquire Property, Plant, and Equipment         270,000,000  
North Central Wind Energy Facilities | Public Service Co Of Oklahoma [Member] | Vertically Integrated Utilities [Member]            
Percentage of an Asset Acquired     45.50%      
North Central Wind Energy Facilities | Southwestern Electric Power Co [Member] | Vertically Integrated Utilities [Member]            
Percentage of an Asset Acquired     54.50%      
Competitive Contracted Renewables | Generation and Marketing [Member]            
Equity Method Investment, Ownership Percentage     50.00%      
Disposal Group, Including Discontinued Operation, Income Statement Disclosures            
Proceeds from Sales of Assets     $ 1,200,000,000      
Gain (Loss) on Disposition of Business net of Tax     73,000,000      
Gain (Loss) on Disposition of Business     93,000,000      
Rock Falls [Member] | Public Service Co Of Oklahoma [Member] | Vertically Integrated Utilities [Member]            
Payments to Acquire Property, Plant, and Equipment     146,000,000      
Noncontrolling Interests [Member] | Dry Lake Solar Project [Member]            
Noncash Contribution of Assets by Noncontrolling Interest     $ 0 $ 0 $ 35,300,000  
[1] Includes ARO related to wind farms.
[2] Includes ARO related to Sabine and DHLC.
[3] Includes ARO related to ash disposal facilities.
[4] Includes ARO related to asbestos removal.
[5] Includes ARO related to nuclear decommissioning costs for the Cook Plant of $2.11 billion and $2 billion as of December 31, 2023 and 2022, respectively.
[6] Includes ARO related to solar farms.