v3.24.0.1
Effects of Regulation (Details) - USD ($)
$ in Millions
 1 Months Ended 12 Months Ended
Feb. 26, 2024
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Regulated Generating Unit to be Retired        
Net Investment   $ 76,693.4 $ 73,339.1  
Materials and Supplies   1,025.8 915.1  
Annual Depreciation   2,927.5 3,072.8 $ 2,717.1
Regulatory Assets        
Current Regulatory Assets   514.0 1,310.0  
Noncurrent Regulatory Assets   5,092.4 4,762.0  
Regulatory Liabilities        
Current Regulatory Liabilities   26.5 1.4  
Noncurrent Regulatory Liabilities   8,182.4 8,115.6  
Effects of Regulation Textuals [Abstract]        
Revisions in Cash Flow Estimates [1],[2],[3],[4],[5],[6],[7]   63.0 100.3  
Secured Debt   368.9 487.8  
Accumulated Depreciation and Amortization   24,553.0 23,682.3  
Asset Impairments and Other Related Charges   85.6 48.8 11.6
Net Investment   76,693.4 73,339.1  
AEP Texas Inc. [Member]        
Regulated Generating Unit to be Retired        
Net Investment   12,774.0 11,681.6  
Materials and Supplies   190.4 138.8  
Annual Depreciation   380.0 363.5 327.2
Regulatory Assets        
Noncurrent Regulatory Assets   315.3 298.3  
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   1,261.4 1,259.6  
Effects of Regulation Textuals [Abstract]        
Revisions in Cash Flow Estimates [3],[4],[6]   0.1 0.0  
Secured Debt   221.8 314.4  
Accumulated Depreciation and Amortization   1,887.9 1,760.7  
Net Investment   12,774.0 11,681.6  
AEP Transmission Co [Member]        
Regulated Generating Unit to be Retired        
Net Investment   14,497.7 13,339.9  
Materials and Supplies   0.0 10.7  
Annual Depreciation   393.8 346.2 297.3
Regulatory Assets        
Noncurrent Regulatory Assets   3.1 7.2  
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   783.7 723.3  
Effects of Regulation Textuals [Abstract]        
Accumulated Depreciation and Amortization   1,291.3 1,027.0  
Net Investment   14,497.7 13,339.9  
Appalachian Power Co [Member]        
Regulated Generating Unit to be Retired        
Net Investment   12,931.5 12,379.2  
Materials and Supplies   148.4 130.6  
Annual Depreciation   571.1 576.1 547.0
Regulatory Assets        
Current Regulatory Assets   155.4 473.1  
Noncurrent Regulatory Assets   1,155.1 1,058.6  
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   1,081.9 1,143.6  
Effects of Regulation Textuals [Abstract]        
Revisions in Cash Flow Estimates [3],[4],[6]   26.5 17.0  
Secured Debt   147.0 173.3  
Accumulated Depreciation and Amortization   5,688.7 5,402.0  
Asset Impairments and Other Related Charges   0.0 24.9 0.0
Net Investment   12,931.5 12,379.2  
Indiana Michigan Power Co [Member]        
Regulated Generating Unit to be Retired        
Net Investment   7,629.0 7,411.5  
Materials and Supplies   208.2 188.1  
Annual Depreciation   439.8 511.9 424.9
Regulatory Assets        
Current Regulatory Assets   14.8 47.1  
Noncurrent Regulatory Assets   406.3 459.6  
Regulatory Liabilities        
Current Regulatory Liabilities   23.2 0.0  
Noncurrent Regulatory Liabilities   2,052.3 1,702.2  
Effects of Regulation Textuals [Abstract]        
Revisions in Cash Flow Estimates [3],[4],[5],[6]   2.0 7.7  
Accumulated Depreciation and Amortization   4,378.4 4,132.8  
Net Investment   7,629.0 7,411.5  
Ohio Power Co [Member]        
Regulated Generating Unit to be Retired        
Net Investment   9,299.9 8,609.3  
Materials and Supplies   175.0 109.5  
Annual Depreciation   315.8 293.1 301.1
Regulatory Assets        
Current Regulatory Assets   0.0 3.8  
Noncurrent Regulatory Assets   455.0 327.3  
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   1,003.6 1,044.0  
Effects of Regulation Textuals [Abstract]        
Revisions in Cash Flow Estimates [4],[6]   0.0 0.0  
Accumulated Depreciation and Amortization   2,713.6 2,565.3  
Net Investment   9,299.9 8,609.3  
Public Service Co Of Oklahoma [Member]        
Regulated Generating Unit to be Retired        
Net Investment   6,112.3 5,626.5  
Materials and Supplies   106.9 111.1  
Annual Depreciation   240.3 226.2 185.9
Regulatory Assets        
Current Regulatory Assets   118.3 178.7  
Noncurrent Regulatory Assets   522.7 653.7  
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   765.6 809.1  
Effects of Regulation Textuals [Abstract]        
Revisions in Cash Flow Estimates [1],[3],[4],[6]   (0.8) 1.9  
Accumulated Depreciation and Amortization   2,081.9 1,837.7  
Net Investment   6,112.3 5,626.5  
Southwestern Electric Power Co [Member]        
Regulated Generating Unit to be Retired        
Net Investment   8,558.4 8,262.2  
Materials and Supplies   88.4 92.1  
Annual Depreciation   323.4 319.3 292.9
Regulatory Assets        
Current Regulatory Assets   170.8 353.0  
Noncurrent Regulatory Assets   1,131.8 1,042.4  
Regulatory Liabilities        
Current Regulatory Liabilities   3.3 1.4  
Noncurrent Regulatory Liabilities   756.1 825.7  
Effects of Regulation Textuals [Abstract]        
Revisions in Cash Flow Estimates [1],[2],[3],[4],[6]   34.5 56.7  
Accumulated Depreciation and Amortization   3,087.2 3,527.3  
Asset Impairments and Other Related Charges   85.6 0.0 $ 11.6
Net Investment   8,558.4 8,262.2  
Net Under-Recovered Fuel Costs   77.0    
Regulatory Liabilities Approved for Payment [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   7,974.5 7,961.8  
Regulatory Liabilities Approved for Payment [Member] | AEP Texas Inc. [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   1,246.9 1,244.8  
Regulatory Liabilities Approved for Payment [Member] | Appalachian Power Co [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   1,054.3 1,113.1  
Regulatory Liabilities Approved for Payment [Member] | Indiana Michigan Power Co [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   2,132.5 1,789.9  
Regulatory Liabilities Approved for Payment [Member] | Ohio Power Co [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   946.4 1,043.8  
Regulatory Liabilities Approved for Payment [Member] | Public Service Co Of Oklahoma [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   764.4 757.8  
Regulatory Liabilities Approved for Payment [Member] | Southwestern Electric Power Co [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   749.1 818.7  
Regulatory Liabilities Pending Final Regulatory Determination [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   207.9 153.8  
Regulatory Liabilities Pending Final Regulatory Determination [Member] | AEP Texas Inc. [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   14.5 14.8  
Regulatory Liabilities Pending Final Regulatory Determination [Member] | AEP Transmission Co [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   8.7 8.7  
Regulatory Liabilities Pending Final Regulatory Determination [Member] | Appalachian Power Co [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   27.6 30.5  
Regulatory Liabilities Pending Final Regulatory Determination [Member] | Indiana Michigan Power Co [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   (80.2) (87.7)  
Regulatory Liabilities Pending Final Regulatory Determination [Member] | Ohio Power Co [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   57.2 0.2  
Regulatory Liabilities Pending Final Regulatory Determination [Member] | Public Service Co Of Oklahoma [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   1.2 51.3  
Regulatory Liabilities Pending Final Regulatory Determination [Member] | Southwestern Electric Power Co [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   7.0 7.0  
Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   5,823.1 5,983.4  
Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member] | AEP Texas Inc. [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   1,212.9 1,202.7  
Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member] | AEP Transmission Co [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   775.0 714.6  
Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Appalachian Power Co [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   1,000.0 1,005.1  
Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Indiana Michigan Power Co [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   311.6 365.5  
Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Ohio Power Co [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   883.7 918.4  
Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Public Service Co Of Oklahoma [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   713.2 696.4  
Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Southwestern Electric Power Co [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   740.0 811.0  
Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Pending Final Regulatory Determination [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   103.1 149.7  
Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Pending Final Regulatory Determination [Member] | AEP Texas Inc. [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   13.0 13.0  
Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Pending Final Regulatory Determination [Member] | Appalachian Power Co [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   7.9 30.5  
Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Pending Final Regulatory Determination [Member] | Indiana Michigan Power Co [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   (103.0) (87.7)  
Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Pending Final Regulatory Determination [Member] | Public Service Co Of Oklahoma [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   0.0 51.3  
Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   2,151.4 1,978.4  
Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | AEP Texas Inc. [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   34.0 42.1  
Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Appalachian Power Co [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   54.3 108.0  
Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Indiana Michigan Power Co [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   1,820.9 1,424.4  
Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Ohio Power Co [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   62.7 125.4  
Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Public Service Co Of Oklahoma [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   51.2 61.4  
Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Southwestern Electric Power Co [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   9.1 7.7  
Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Pending Final Regulatory Determination [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   104.8 4.1  
Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Pending Final Regulatory Determination [Member] | AEP Texas Inc. [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   1.5 1.8  
Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Pending Final Regulatory Determination [Member] | Appalachian Power Co [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   19.7 0.0  
Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Pending Final Regulatory Determination [Member] | Indiana Michigan Power Co [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   22.8 0.0  
Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Pending Final Regulatory Determination [Member] | Public Service Co Of Oklahoma [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   1.2 0.0  
Regulatory Assets Pending Final Regulatory Approval [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   837.3 882.1  
Regulatory Assets Pending Final Regulatory Approval [Member] | AEP Texas Inc. [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   64.3 67.0  
Regulatory Assets Pending Final Regulatory Approval [Member] | Appalachian Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   125.5 144.5  
Regulatory Assets Pending Final Regulatory Approval [Member] | Indiana Michigan Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   33.2 23.7  
Regulatory Assets Pending Final Regulatory Approval [Member] | Ohio Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   23.6 33.8  
Regulatory Assets Pending Final Regulatory Approval [Member] | Southwestern Electric Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   407.8 510.2  
Regulatory Assets Approved for Recovery [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   4,255.1 3,879.9  
Regulatory Assets Approved for Recovery [Member] | AEP Texas Inc. [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   251.0 231.3  
Regulatory Assets Approved for Recovery [Member] | AEP Transmission Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   3.1 7.2  
Regulatory Assets Approved for Recovery [Member] | Appalachian Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   1,029.6 914.1  
Regulatory Assets Approved for Recovery [Member] | Indiana Michigan Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   373.1 435.9  
Regulatory Assets Approved for Recovery [Member] | Ohio Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   431.4 293.5  
Regulatory Assets Approved for Recovery [Member] | Public Service Co Of Oklahoma [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   434.0 628.1  
Regulatory Assets Approved for Recovery [Member] | Southwestern Electric Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   724.0 532.2  
Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   349.9 355.6  
Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | AEP Texas Inc. [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   0.0 17.6  
Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Appalachian Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   0.6 7.0  
Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Indiana Michigan Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   0.2 0.1  
Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Southwestern Electric Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   338.1 330.9  
Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   1,946.9 1,858.6  
Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | AEP Texas Inc. [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   43.5 17.5  
Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Appalachian Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   340.3 299.3  
Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Indiana Michigan Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   229.3 270.6  
Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Ohio Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   44.0 34.9  
Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Public Service Co Of Oklahoma [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   325.3 552.8  
Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Southwestern Electric Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   483.1 321.8  
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   487.4 526.5  
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | AEP Texas Inc. [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   64.3 49.4  
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Appalachian Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   124.9 137.5  
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Indiana Michigan Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   33.0 23.6  
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Public Service Co Of Oklahoma [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   88.7 25.6  
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Southwestern Electric Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   69.7 179.3  
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   2,308.2 2,021.3  
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | AEP Texas Inc. [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   207.5 213.8  
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Appalachian Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   689.3 614.8  
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Indiana Michigan Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   143.8 165.3  
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Ohio Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   387.4 258.6  
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Public Service Co Of Oklahoma [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   108.7 75.3  
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Southwestern Electric Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   240.9 210.4  
Northeastern Plant, Unit 3 [Member] | Generating Units Probable of Abandonment [Member] | Public Service Co Of Oklahoma [Member]        
Regulated Generating Unit to be Retired        
Net Investment   104.5    
Accelerated Depreciation Regulatory Asset   164.2    
Cost of Removal Regulatory Liability [8]   $ 20.5    
Expected Retirement Date [9]   2026    
Annual Depreciation [10]   $ 15.0    
Effects of Regulation Textuals [Abstract]        
Net Investment   104.5    
Pirkey Power Plant [Member] | Southwestern Electric Power Co [Member] | TEXAS        
Regulated Generating Unit to be Retired        
Net Investment   67.0    
Effects of Regulation Textuals [Abstract]        
Net Investment   67.0    
Welsh Plant, Units 1 and 3 [Member] | Generating Units Probable of Abandonment [Member] | Southwestern Electric Power Co [Member]        
Regulated Generating Unit to be Retired        
Net Investment   352.0    
Accelerated Depreciation Regulatory Asset   125.6    
Cost of Removal Regulatory Liability [11]   $ 58.2    
Expected Retirement Date [12],[13]   2028    
Annual Depreciation [10]   $ 38.6    
Effects of Regulation Textuals [Abstract]        
Net Investment   352.0    
Deferred Fuel Costs [Member] | Regulatory Liabilities Currently Paying a Return [Member]        
Regulatory Liabilities        
Current Regulatory Liabilities   $ 3.3 1.4  
Remaining Refund Period   1 year    
Deferred Fuel Costs [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Southwestern Electric Power Co [Member]        
Regulatory Liabilities        
Current Regulatory Liabilities [14]   $ 3.3 1.4  
Remaining Refund Period   1 year    
Deferred Fuel Costs [Member] | Regulatory Liabilities Currently Not Paying Return [Member]        
Regulatory Liabilities        
Current Regulatory Liabilities   $ 23.2 0.0  
Remaining Refund Period   1 year    
Deferred Fuel Costs [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Indiana Michigan Power Co [Member] | Indiana        
Regulatory Liabilities        
Current Regulatory Liabilities   $ 23.2 0.0  
Remaining Refund Period   1 year    
Deferred Fuel Costs [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Ohio Power Co [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   $ 26.1 32.2  
Remaining Refund Period   9 years    
Deferred Fuel Costs [Member] | Regulatory Assets Currently Earning Return [Member]        
Regulatory Assets        
Current Regulatory Assets   $ 357.4 625.7  
Remaining Recovery Period   1 year    
Deferred Fuel Costs [Member] | Regulatory Assets Currently Earning Return [Member] | Appalachian Power Co [Member]        
Regulatory Assets        
Current Regulatory Assets   $ 147.4 180.7  
Remaining Recovery Period   1 year    
Deferred Fuel Costs [Member] | Regulatory Assets Currently Earning Return [Member] | Indiana Michigan Power Co [Member] | Michigan        
Regulatory Assets        
Current Regulatory Assets   $ 14.8 9.0  
Remaining Recovery Period   1 year    
Deferred Fuel Costs [Member] | Regulatory Assets Currently Earning Return [Member] | Public Service Co Of Oklahoma [Member]        
Regulatory Assets        
Current Regulatory Assets   $ 118.3 178.7  
Remaining Recovery Period   1 year    
Deferred Fuel Costs [Member] | Regulatory Assets Currently Earning Return [Member] | Southwestern Electric Power Co [Member]        
Regulatory Assets        
Current Regulatory Assets [15]   $ 76.9 257.2  
Remaining Recovery Period   1 year    
Deferred Fuel Costs [Member] | Regulatory Assets Currently Not Earning Return [Member]        
Regulatory Assets        
Current Regulatory Assets   $ 62.7 588.5  
Remaining Recovery Period   1 year    
Deferred Fuel Costs [Member] | Regulatory Assets Currently Not Earning Return [Member] | Appalachian Power Co [Member]        
Regulatory Assets        
Current Regulatory Assets   $ 8.0 292.4  
Remaining Recovery Period   1 year    
Deferred Fuel Costs [Member] | Regulatory Assets Currently Not Earning Return [Member] | Indiana Michigan Power Co [Member] | Indiana        
Regulatory Assets        
Current Regulatory Assets   $ 0.0 38.1  
Deferred Fuel Costs [Member] | Regulatory Assets Currently Not Earning Return [Member] | Ohio Power Co [Member]        
Regulatory Assets        
Current Regulatory Assets   $ 0.0 3.8  
Remaining Recovery Period   1 year    
Dolet Hills Power Station Accelerated Depreciation [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Southwestern Electric Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets [16]   $ 12.0 9.7  
Kentucky Deferred Purchase Power Expenses [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 43.5 53.0  
Remaining Recovery Period   4 years    
Pirkey Power Plant Accelerated Depreciation [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 114.4 116.5  
Pirkey Power Plant Accelerated Depreciation [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Southwestern Electric Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   114.4 116.5  
Pirkey Power Plant Accelerated Depreciation [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Louisiana Jurisdiction [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 65.8 63.0  
Remaining Recovery Period   9 years    
Pirkey Power Plant Accelerated Depreciation [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Southwestern Electric Power Co [Member] | Louisiana Jurisdiction [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 65.8 63.0  
Remaining Recovery Period   9 years    
Welsh Plant, Units 1 and 3 Accelerated Depreciation [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 125.6 85.6  
Welsh Plant, Units 1 and 3 Accelerated Depreciation [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Southwestern Electric Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   125.6 85.6  
Other Regulatory Assets Pending Final Regulatory Approval [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   49.8 68.9  
Other Regulatory Assets Pending Final Regulatory Approval [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Appalachian Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   0.6 7.0  
Other Regulatory Assets Pending Final Regulatory Approval [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Indiana Michigan Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   0.2 0.1  
Other Regulatory Assets Pending Final Regulatory Approval [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Southwestern Electric Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   26.0 34.5  
Other Regulatory Assets Pending Final Regulatory Approval [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   78.5 81.5  
Other Regulatory Assets Pending Final Regulatory Approval [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | AEP Texas Inc. [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   11.7 8.9  
Other Regulatory Assets Pending Final Regulatory Approval [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Appalachian Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   7.5 1.1  
Other Regulatory Assets Pending Final Regulatory Approval [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Indiana Michigan Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   3.3 2.0  
Other Regulatory Assets Pending Final Regulatory Approval [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Public Service Co Of Oklahoma [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   0.2 0.1  
Other Regulatory Assets Pending Final Regulatory Approval [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Southwestern Electric Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   13.7 16.0  
Storm Related Costs [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 170.9 8.4  
Remaining Recovery Period   5 years    
Storm Related Costs [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Public Service Co Of Oklahoma [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 26.2 8.4  
Remaining Recovery Period   5 years    
Storm Related Costs [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Southwestern Electric Power Co [Member] | Louisiana Jurisdiction [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 144.7 0.0  
Remaining Recovery Period   2 years    
Storm Related Costs [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 408.9 407.1  
Storm Related Costs [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | AEP Texas Inc. [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   37.7 26.7  
Storm Related Costs [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Appalachian Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   91.5 72.6  
Storm Related Costs [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Indiana Michigan Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   29.7 21.6  
Storm Related Costs [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Ohio Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   23.6 33.8  
Storm Related Costs [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Public Service Co Of Oklahoma [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   88.5 25.5  
Storm Related Costs [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Southwestern Electric Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   56.0 151.5  
Storm Related Costs [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 38.5 11.9  
Remaining Recovery Period   2 years    
Storm Related Costs [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | AEP Texas Inc. [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 4.3 8.5  
Remaining Recovery Period   2 years    
Storm Related Costs [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Ohio Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 30.9 0.0  
Remaining Recovery Period   1 year    
Plant Retirement Costs - Asset Retirement Obligation Costs [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 110.8 110.6  
Remaining Recovery Period   19 years    
Plant Retirement Costs - Asset Retirement Obligation Costs [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Appalachian Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 25.9 25.9  
Plant Retirement Costs - Asset Retirement Obligation Costs [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 330.2 308.5  
Remaining Recovery Period   19 years    
Plant Retirement Costs - Asset Retirement Obligation Costs [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Appalachian Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 324.7 303.1  
Remaining Recovery Period   15 years    
Vegetation Management Program [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | AEP Texas Inc. [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 5.2 5.2  
Vegetation Management Program [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | AEP Texas Inc. [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 6.8 12.1  
Remaining Recovery Period   2 years    
Plant Retirement Costs - Unrecovered Plant [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets [17]   $ 664.2 689.9  
Remaining Recovery Period   23 years    
Plant Retirement Costs - Unrecovered Plant [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Appalachian Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 72.0 75.6  
Remaining Recovery Period   20 years    
Plant Retirement Costs - Unrecovered Plant [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Indiana Michigan Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 122.5 147.0  
Remaining Recovery Period   5 years    
Plant Retirement Costs - Unrecovered Plant [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Public Service Co Of Oklahoma [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets [18]   $ 254.1 240.6  
Remaining Recovery Period   23 years    
Plant Retirement Costs - Unrecovered Plant, Arkansas [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Southwestern Electric Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 44.4 13.1  
Remaining Recovery Period   19 years    
Plant Retirement Costs - Unrecovered Plant, Arkansas [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Southwestern Electric Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 17.3 21.1  
Remaining Recovery Period   4 years    
Plant Retirement Costs - Unrecovered Plant, Texas [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 48.7 51.7  
Remaining Recovery Period   23 years    
Plant Retirement Costs - Unrecovered Plant, Texas [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Southwestern Electric Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 48.7 51.7  
Remaining Recovery Period   23 years    
Meter Replacement Costs [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 23.5 34.2  
Remaining Recovery Period   4 years    
Meter Replacement Costs [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | AEP Texas Inc. [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 9.4 16.1  
Remaining Recovery Period   2 years    
Meter Replacement Costs [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Public Service Co Of Oklahoma [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 14.1 18.1  
Remaining Recovery Period   4 years    
Ohio Distribution Decoupling [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Ohio Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 1.8 19.5  
Remaining Recovery Period   2 years    
Ohio Basic Transmission Cost Rider [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 42.2 14.3  
Remaining Recovery Period   2 years    
Ohio Basic Transmission Cost Rider [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Ohio Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 42.2 14.3  
Remaining Recovery Period   2 years    
Environmental Controls Projects [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 31.4 33.9  
Remaining Recovery Period   17 years    
Environmental Controls Projects [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Public Service Co Of Oklahoma [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 22.5 23.9  
Remaining Recovery Period   17 years    
Environmental Controls Projects [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Southwestern Electric Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 8.9 10.0  
Remaining Recovery Period   9 years    
Rockport Plant Dry Sorbent Injection System and Selective Catalytic Reduction [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 46.9 56.6  
Remaining Recovery Period   5 years    
Rockport Plant Dry Sorbent Injection System and Selective Catalytic Reduction [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Indiana Michigan Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 46.9 56.6  
Remaining Recovery Period   5 years    
Cook Plant Uprate Project [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Indiana Michigan Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 22.9 25.3  
Remaining Recovery Period   10 years    
Other Regulatory Assets Approved for Recovery [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 101.4 125.0  
Other Regulatory Assets Approved for Recovery [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | AEP Texas Inc. [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   0.7 1.4  
Other Regulatory Assets Approved for Recovery [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Appalachian Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   7.1 0.4  
Other Regulatory Assets Approved for Recovery [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Indiana Michigan Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   17.5 20.6  
Other Regulatory Assets Approved for Recovery [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Public Service Co Of Oklahoma [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   8.4 9.1  
Other Regulatory Assets Approved for Recovery [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Southwestern Electric Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   4.9 6.8  
Other Regulatory Assets Approved for Recovery [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   271.5 262.7  
Other Regulatory Assets Approved for Recovery [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | AEP Texas Inc. [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   4.0 8.1  
Other Regulatory Assets Approved for Recovery [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Appalachian Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   17.5 12.3  
Other Regulatory Assets Approved for Recovery [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Indiana Michigan Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   21.0 19.7  
Other Regulatory Assets Approved for Recovery [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Ohio Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   11.6 14.9  
Other Regulatory Assets Approved for Recovery [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Public Service Co Of Oklahoma [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   16.2 20.1  
Other Regulatory Assets Approved for Recovery [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Southwestern Electric Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   30.1 35.0  
Asset Retirement Obligation - Louisiana [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Southwestern Electric Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   0.0 11.8  
Deferred Cook Plant Life Cycle Management Project Costs [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Indiana Michigan Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 11.1 12.1  
Remaining Recovery Period   11 years    
Cook Plant Turbine [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Indiana Michigan Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 8.4 9.0  
Remaining Recovery Period   15 years    
Pension Costs [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 1,054.1 975.4  
Remaining Recovery Period   12 years    
Pension Costs [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | AEP Texas Inc. [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 183.2 173.2  
Remaining Recovery Period   12 years    
Pension Costs [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Appalachian Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 115.8 108.3  
Remaining Recovery Period   12 years    
Pension Costs [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Indiana Michigan Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 25.4 26.9  
Remaining Recovery Period   12 years    
Pension Costs [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Ohio Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 147.1 142.7  
Remaining Recovery Period   12 years    
Pension Costs [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Public Service Co Of Oklahoma [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 62.6 55.2  
Remaining Recovery Period   12 years    
Pension Costs [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Southwestern Electric Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 109.2 96.2  
Remaining Recovery Period   12 years    
Unamortized Loss on Reacquired Debt [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 97.2 104.1  
Remaining Recovery Period   25 years    
Unamortized Loss on Reacquired Debt [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Appalachian Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 70.7 74.4  
Remaining Recovery Period   22 years    
Unamortized Loss on Reacquired Debt [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Indiana Michigan Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 11.8 12.9  
Remaining Recovery Period   25 years    
Peak Demand Reduction/Energy Efficiency [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | AEP Texas Inc. [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 9.2 11.9  
Remaining Recovery Period   2 years    
Peak Demand Reduction/Energy Efficiency [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Appalachian Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 15.0 15.8  
Remaining Recovery Period   3 years    
Unrealized Loss on Forward Commitments [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 131.4 40.1  
Remaining Recovery Period   9 years    
Unrealized Loss on Forward Commitments [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Appalachian Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 21.9 0.0  
Remaining Recovery Period   3 years    
Unrealized Loss on Forward Commitments [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Ohio Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 50.8 40.0  
Remaining Recovery Period   9 years    
Unrealized Loss on Forward Commitments [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Public Service Co Of Oklahoma [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 29.9 0.0  
Remaining Recovery Period   2 years    
Unrealized Loss on Forward Commitments [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Southwestern Electric Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 15.4 0.0  
Remaining Recovery Period   2 years    
Virginia Transmission Rate Adjustment Clause [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Appalachian Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 25.5 18.7  
Remaining Recovery Period   2 years    
Vegetation Management Program - West Virginia [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Appalachian Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 12.9 13.7  
Remaining Recovery Period   2 years    
Cook Nuclear Plant Refueling Outage Levelization [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 55.7 81.2  
Remaining Recovery Period   2 years    
Cook Nuclear Plant Refueling Outage Levelization [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Indiana Michigan Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 55.7 81.2  
Remaining Recovery Period   2 years    
PJM/SPP Annual Formula Rate True Up [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | AEP Transmission Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 3.1 7.2  
Remaining Recovery Period   2 years    
Postemployment Benefits [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 30.6 32.1  
Remaining Recovery Period   3 years    
Postemployment Benefits [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Appalachian Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 14.9 13.7  
Remaining Recovery Period   3 years    
Postemployment Benefits [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Indiana Michigan Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 7.0 7.7  
Remaining Recovery Period   3 years    
OVEC Purchased Power [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   $ 0.0 47.1  
OVEC Purchased Power [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Ohio Power Co [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   0.0 47.1  
OVEC Purchased Power [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 50.1 0.0  
Remaining Recovery Period   2 years    
OVEC Purchased Power [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Ohio Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 50.1 0.0  
Remaining Recovery Period   2 years    
Fuel and Purchased Power Adjustment Rider [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 68.3 76.3  
Remaining Recovery Period   2 years    
PJM Costs and Off-system Sales Margin Sharing - Indiana [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   $ 14.1 34.2  
Remaining Refund Period   2 years    
PJM Costs and Off-system Sales Margin Sharing - Indiana [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Indiana Michigan Power Co [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   $ 14.1 34.2  
Remaining Refund Period   2 years    
Other Regulatory Liabilities Pending Final Regulatory Determination [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Pending Final Regulatory Determination [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   $ 1.7 4.1  
Other Regulatory Liabilities Pending Final Regulatory Determination [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Pending Final Regulatory Determination [Member] | AEP Texas Inc. [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   1.5 1.8  
Other Regulatory Liabilities Pending Final Regulatory Determination [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Pending Final Regulatory Determination [Member] | Ohio Power Co [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   0.2 0.2  
Excess ADIT that is Not Subject to Rate Normalization Requirements [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   $ 228.0 277.0  
Remaining Refund Period   5 years    
Excess ADIT that is Not Subject to Rate Normalization Requirements [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member] | AEP Transmission Co [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   $ 13.0 16.0  
Remaining Refund Period   5 years    
Excess ADIT that is Not Subject to Rate Normalization Requirements [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Appalachian Power Co [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   $ 35.0 19.0  
Remaining Refund Period   5 years    
Excess ADIT that is Not Subject to Rate Normalization Requirements [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Indiana Michigan Power Co [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   $ 25.0 42.0  
Remaining Refund Period   5 years    
Excess ADIT that is Not Subject to Rate Normalization Requirements [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Ohio Power Co [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   $ 132.0 162.0  
Remaining Refund Period   5 years    
Excess ADIT that is Not Subject to Rate Normalization Requirements [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Public Service Co Of Oklahoma [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   $ 51.0 21.0  
Remaining Refund Period   1 year    
Asset Removal Costs [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities [19]   $ 3,563.5 3,392.4  
Asset Removal Costs [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member] | AEP Texas Inc. [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities [20]   797.1 766.8  
Asset Removal Costs [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member] | AEP Transmission Co [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities [21]   466.3 358.8  
Asset Removal Costs [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Appalachian Power Co [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities [22]   759.6 713.5  
Asset Removal Costs [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Indiana Michigan Power Co [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities [23]   168.1 170.7  
Asset Removal Costs [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Ohio Power Co [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities [24]   475.5 466.5  
Asset Removal Costs [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Public Service Co Of Oklahoma [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities [25]   317.5 316.3  
Asset Removal Costs [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Southwestern Electric Power Co [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities [26]   443.2 481.2  
Deferred Investment Tax Credits [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Appalachian Power Co [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   $ 0.3 0.3  
Remaining Refund Period   30 years    
Deferred Investment Tax Credits [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   $ 154.5 237.3  
Remaining Refund Period   31 years    
Deferred Investment Tax Credits [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Indiana Michigan Power Co [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   $ 15.8 17.4  
Remaining Refund Period   27 years    
Deferred Investment Tax Credits [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Public Service Co Of Oklahoma [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   $ 47.2 48.2  
Remaining Refund Period   18 years    
Other Regulatory Liabilities Approved for Payment [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   $ 35.0 32.7  
Other Regulatory Liabilities Approved for Payment [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member] | AEP Texas Inc. [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   3.8 4.3  
Other Regulatory Liabilities Approved for Payment [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Indiana Michigan Power Co [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   0.1 3.0  
Other Regulatory Liabilities Approved for Payment [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Southwestern Electric Power Co [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   4.4 2.2  
Other Regulatory Liabilities Approved for Payment [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   96.0 129.2  
Other Regulatory Liabilities Approved for Payment [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | AEP Texas Inc. [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   7.4 12.7  
Other Regulatory Liabilities Approved for Payment [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Appalachian Power Co [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   14.6 20.8  
Other Regulatory Liabilities Approved for Payment [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Indiana Michigan Power Co [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   4.8 8.5  
Other Regulatory Liabilities Approved for Payment [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Ohio Power Co [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   3.6 7.8  
Other Regulatory Liabilities Approved for Payment [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Public Service Co Of Oklahoma [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   4.0 13.2  
Other Regulatory Liabilities Approved for Payment [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Southwestern Electric Power Co [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   9.1 7.7  
Excess Nuclear Decommissioning Funding [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities [27]   1,721.9 1,318.5  
Excess Nuclear Decommissioning Funding [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Indiana Michigan Power Co [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities [28]   1,721.9 1,318.5  
PJM Transmission Enhancement Refund [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   $ 22.8 34.1  
Remaining Refund Period   2 years    
PJM Transmission Enhancement Refund [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Ohio Power Co [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   $ 9.8 14.7  
Remaining Refund Period   2 years    
Transition and Restoration Charges [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | AEP Texas Inc. [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   $ 26.6 29.4  
Remaining Refund Period   6 years    
2017-2019 Virginia Triennial Revenue Provision [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   $ 37.1 39.1  
Remaining Refund Period   26 years    
2017-2019 Virginia Triennial Revenue Provision [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Appalachian Power Co [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   $ 37.1 39.1  
Remaining Refund Period   26 years    
2017-2019 Virginia Triennial Revenue Provision [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Appalachian Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 2.3 30.1  
Remaining Recovery Period   1 year    
Spent Nuclear Fuel [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities [27]   $ 47.6 45.8  
Spent Nuclear Fuel [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Indiana Michigan Power Co [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities [28]   47.6 45.8  
Peak Demand Reduction/Energy Efficiency [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Ohio Power Co [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   $ 23.2 23.6  
Remaining Refund Period   2 years    
Peak Demand Reduction/Energy Efficiency [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 23.9 41.7  
Remaining Recovery Period   3 years    
Peak Demand Reduction/Energy Efficiency [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Indiana Michigan Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 0.0 10.3  
Ohio Enhanced Service Reliability Plan [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 35.3 33.3  
Remaining Recovery Period   2 years    
Ohio Enhanced Service Reliability Plan [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Ohio Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 35.3 33.3  
Remaining Recovery Period   2 years    
Smart Grid Costs [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Ohio Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 26.3 25.4  
Remaining Recovery Period   2 years    
Distribution Investment Rider [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 35.3 2.3  
Remaining Recovery Period   2 years    
Distribution Investment Rider [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Ohio Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 35.3 2.3  
Remaining Recovery Period   2 years    
Dolet Hills Generating Station and Related Fuel Operations | Southwestern Electric Power Co [Member]        
Effects of Regulation Textuals [Abstract]        
Share of Net Investment in Dolet Hills Power Station   $ 103.0    
Dolet Hills Generating Station and Related Fuel Operations | Southwestern Electric Power Co [Member] | TEXAS        
Effects of Regulation Textuals [Abstract]        
Oxbow Mine Related Costs Recovery Request   48.0    
Dolet Hills Generating Station and Related Fuel Operations | Southwestern Electric Power Co [Member] | Arkansas        
Effects of Regulation Textuals [Abstract]        
Amount of Dolet Hills Fuel Costs Approved to Recover   20.0    
Dolet Hills Generating Station and Related Fuel Operations | Southwestern Electric Power Co [Member] | Louisiana Jurisdiction [Member]        
Effects of Regulation Textuals [Abstract]        
Amount of Dolet Hills Fuel Costs Approved to Recover   20.0    
Approved Deferral of Dolet Hills Fuel Costs   35.0    
Recommended Dolet Hills Fuel Disallowance   55.0    
Dolet Hills Generating Station and Related Fuel Operations | Southwestern Electric Power Co [Member] | Louisiana Jurisdiction [Member] | Subsequent Event [Member]        
Effects of Regulation Textuals [Abstract]        
ALJ Recommended Customer Refund $ 55.0      
ALJ Recommended Denial of Recovery for Fuel Costs Deferral $ 35.0      
Pirkey Power Plant and Related Fuel Operations | Southwestern Electric Power Co [Member]        
Effects of Regulation Textuals [Abstract]        
Share of Net Investment in Pirkey Power Plant   182.0    
Pirkey Power Plant and Related Fuel Operations | Southwestern Electric Power Co [Member] | TEXAS        
Effects of Regulation Textuals [Abstract]        
Oxbow Mine Related Costs Recovery Request   33.0    
Dolet Hills Power Station [Member] | Southwestern Electric Power Co [Member] | TEXAS        
Effects of Regulation Textuals [Abstract]        
Asset Impairments and Other Related Charges   12.0    
Dolet Hills Power Station [Member] | Southwestern Electric Power Co [Member] | Arkansas        
Effects of Regulation Textuals [Abstract]        
Asset Impairments and Other Related Charges   2.0    
Unrealized Gain on Forward Commitments [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   0.0 45.2  
Unrealized Gain on Forward Commitments [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Appalachian Power Co [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   0.0 34.5  
February 2021 Severe Storm Fuel Costs | Regulatory Assets Currently Earning Return [Member]        
Regulatory Assets        
Current Regulatory Assets [29]   $ 93.9 95.8  
Remaining Recovery Period   1 year    
February 2021 Severe Storm Fuel Costs | Regulatory Assets Currently Earning Return [Member] | Southwestern Electric Power Co [Member]        
Regulatory Assets        
Current Regulatory Assets [30]   $ 93.9 95.8  
Remaining Recovery Period   1 year    
February 2021 Severe Storm Fuel Costs | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets [29]   $ 60.1 84.6  
February 2021 Severe Storm Fuel Costs | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Southwestern Electric Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets [30]   60.1 84.6  
February 2021 Severe Storm Fuel Costs | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets [29]   $ 99.3 148.6  
Remaining Recovery Period   4 years    
February 2021 Severe Storm Fuel Costs | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Southwestern Electric Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets [30]   $ 99.3 148.6  
Remaining Recovery Period   4 years    
Texas Retail Electric Provider Bad Debt Expense | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | AEP Texas Inc. [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 4.0 4.1  
Environmental Cost Rider - Indiana | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Indiana Michigan Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 8.1 6.6  
Remaining Recovery Period   2 years    
Ohio Economic Development Rider | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Ohio Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 0.0 1.1  
2020-2022 Virginia Triennial Under-Earnings [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   0.0 37.9  
2020-2022 Virginia Triennial Under-Earnings [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Appalachian Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   0.0 37.9  
2020-2022 Virginia Triennial Under-Earnings [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 37.4 0.0  
Remaining Recovery Period   4 years    
2020-2022 Virginia Triennial Under-Earnings [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Appalachian Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 37.4 0.0  
Remaining Recovery Period   4 years    
Long-term Under-recovered Fuel Costs - Oklahoma [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 0.0 252.7  
Long-term Under-recovered Fuel Costs - Oklahoma [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Public Service Co Of Oklahoma [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   0.0 252.7  
Long-term Under-recovered Fuel Costs - Virginia [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 107.0 223.3  
Remaining Recovery Period   2 years    
Long-term Under-recovered Fuel Costs - Virginia [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Appalachian Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 107.0 223.3  
Remaining Recovery Period   2 years    
Plant Retirement Costs - Unrecovered Plant, Dolet Hills Power Station [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Louisiana Jurisdiction [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 40.8 45.1  
Remaining Recovery Period   9 years    
Plant Retirement Costs - Unrecovered Plant, Dolet Hills Power Station [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Southwestern Electric Power Co [Member] | Louisiana Jurisdiction [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 40.8 45.1  
Remaining Recovery Period   9 years    
Income Taxes, Net [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities [31],[32]   $ 2,179.7 2,504.5  
Income Taxes, Net [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member] | AEP Texas Inc. [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities [33],[34]   412.0 431.6  
Income Taxes, Net [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member] | AEP Transmission Co [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities [35],[36]   308.7 355.8  
Income Taxes, Net [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Appalachian Power Co [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities [37],[38]   240.1 291.3  
Income Taxes, Net [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Indiana Michigan Power Co [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities [39],[40]   116.8 168.6  
Income Taxes, Net [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Ohio Power Co [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities [41],[42]   408.2 451.9  
Income Taxes, Net [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Public Service Co Of Oklahoma [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities [43],[44]   395.7 380.1  
Income Taxes, Net [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Southwestern Electric Power Co [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities [45],[46]   292.4 327.6  
Income Taxes, Net [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Pending Final Regulatory Determination [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities [31]   103.1 149.7  
Income Taxes, Net [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Pending Final Regulatory Determination [Member] | AEP Texas Inc. [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities [33]   13.0 13.0  
Income Taxes, Net [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Pending Final Regulatory Determination [Member] | AEP Transmission Co [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities [35]   8.7 8.7  
Income Taxes, Net [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Pending Final Regulatory Determination [Member] | Appalachian Power Co [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities [37]   7.9 30.5  
Income Taxes, Net [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Pending Final Regulatory Determination [Member] | Indiana Michigan Power Co [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities [40],[47]   (103.0) (87.7)  
Income Taxes, Net [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Pending Final Regulatory Determination [Member] | Public Service Co Of Oklahoma [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities [44]   0.0 51.3  
Income Taxes, Net [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Pending Final Regulatory Determination [Member] | Southwestern Electric Power Co [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities [45]   7.0 7.0  
Rockport Plant, Unit 2 Accelerated Depreciation for Leasehold Improvements [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   $ 44.9 53.8  
Remaining Refund Period   5 years    
Renewable Energy Surcharge - Michigan [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Indiana Michigan Power Co [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   $ 26.6 23.2  
Remaining Refund Period   2 years    
Over-recovered Fuel Costs - Ohio [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   $ 26.1 32.2  
Remaining Refund Period   9 years    
Texas Mobile Generation Lease Payments [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | AEP Texas Inc. [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 0.0 17.6  
Texas Mobile Generation Lease Payments [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | AEP Texas Inc. [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 33.4 0.0  
Remaining Recovery Period   2 years    
Virginia Clean Economy Act [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Appalachian Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 8.0 16.7  
Remaining Recovery Period   2 years    
Over-recovered Deferred Wind Costs - Virginia [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Appalachian Power Co [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   $ 2.6 13.6  
Remaining Refund Period   2 years    
Plant Retirement Costs - Unrecovered Plant, Welsh Plant, Unit 2 [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Southwestern Electric Power Co [Member] | Louisiana Jurisdiction [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 0.0 35.2  
Line Inspection Costs [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | AEP Texas Inc. [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   5.7 4.5  
Long-term Under-Recovered Fuel Costs - West Virginia [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 291.5 0.0  
Remaining Recovery Period   11 years    
Long-term Under-Recovered Fuel Costs - West Virginia [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Appalachian Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 154.2 0.0  
Remaining Recovery Period   11 years    
Fuel Mine Closure Costs - Texas [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 74.3 0.0  
Remaining Recovery Period   12 years    
Fuel Mine Closure Costs - Texas [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Southwestern Electric Power Co [Member] | Louisiana Jurisdiction [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 74.3 0.0  
Remaining Recovery Period   12 years    
Texas Mobile Temporary Emergency Electric Energy Facilities Rider [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Louisiana Jurisdiction [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 33.4 0.0  
Remaining Recovery Period   2 years    
Demand Side Management [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   $ 31.3 15.7  
Remaining Refund Period   2 years    
Demand Side Management [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Indiana Michigan Power Co [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   $ 16.7 0.0  
Remaining Refund Period   2 years    
FERC 2021 Transmission Formula Rate Challenge Refunds [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Pending Final Regulatory Determination [Member] | Public Service Co Of Oklahoma [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   $ 1.2 0.0  
FERC 2021 Transmission Formula Rate Challenge Refunds [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Pending Final Regulatory Determination [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   103.1 0.0  
FERC 2021 Transmission Formula Rate Challenge Refunds [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Pending Final Regulatory Determination [Member] | Appalachian Power Co [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   19.7 0.0  
FERC 2021 Transmission Formula Rate Challenge Refunds [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Pending Final Regulatory Determination [Member] | Indiana Michigan Power Co [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   22.8 0.0  
FERC 2021 Transmission Formula Rate Challenge Refunds [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Pending Final Regulatory Determination [Member] | Ohio Power Co [Member]        
Regulatory Liabilities        
Noncurrent Regulatory Liabilities   57.0 0.0  
Excess SO2 Allowance Inventory - Virginia [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Appalachian Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 11.8 0.0  
Remaining Recovery Period   9 years    
Excess SO2 Allowance Inventory - Virginia [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Indiana Michigan Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 14.8 0.0  
Remaining Recovery Period   5 years    
Virginia Generation Rate Adjustment Clause [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Appalachian Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 10.9 8.0  
Remaining Recovery Period   2 years    
North Central Wind Rider [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Southwestern Electric Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 20.2 6.4  
Remaining Recovery Period   2 years    
February 2021 Severe Storm Fuel Costs | Southwestern Electric Power Co [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 253.3 329.0  
February 2021 Severe Storm Fuel Costs | Southwestern Electric Power Co [Member] | Arkansas        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 54.2 74.9  
Remaining Recovery Period   6 years    
February 2021 Severe Storm Fuel Costs | Southwestern Electric Power Co [Member] | Louisiana Jurisdiction [Member]        
Regulatory Assets        
Noncurrent Regulatory Assets   $ 97.2 $ 121.7  
[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] Unless discussed above, primarily related to ash ponds, landfills and mine reclamation, generally due to changes in estimated closure area, volumes and/or unit costs.
[7] Includes ARO related to solar farms.
[8] Includes Northeastern Plant, Unit 4, which was retired in 2016. Removal of Northeastern Plant, Unit 4, will be performed with the removal of Northeastern Plant, Unit 3, after retirement.
[9] Northeastern Plant, Unit 3 is currently being recovered through 2040.
[10] Represents the amount of annual depreciation that has been collected from customers over the prior 12-month period.
[11] Includes Welsh Plant, Unit 2, which was retired in 2016. Removal of Welsh Plant, Unit 2, will be performed with the removal of Welsh Plant, Units 1 and 3, after retirement.
[12] Represents projected retirement date of coal assets, units are being evaluated for conversion to natural gas after 2028.
[13] Unit 1 is being recovered through 2027 in the Louisiana jurisdiction and through 2037 in the Arkansas and Texas jurisdictions. Unit 3 is being recovered through 2032 in the Louisiana jurisdiction and through 2042 in the Arkansas and Texas jurisdictions.
[14] Amounts include Louisiana jurisdiction.
[15] Amounts include Arkansas and Texas jurisdictions.
[16] Amounts include the FERC jurisdiction.
[17] Northeastern Plant, Unit 3 is approved for recovery through 2040, but expected to retire in 2026. PSO records a regulatory asset for accelerated depreciation. See “Regulated Generating Units to be Retired” section above for additional information.
[18] Northeastern Plant, Unit 3 is approved for recovery through 2040, but expected to retire in 2026. PSO records a regulatory asset for accelerated depreciation. See “Regulated Generating Units to be Retired” section above for additional information.
[19] Relieved as removal costs are incurred.
[20] Relieved as removal costs are incurred.
[21] Relieved as removal costs are incurred.
[22] Relieved as removal costs are incurred.
[23] Relieved as removal costs are incurred.
[24] Relieved as removal costs are incurred.
[25] Relieved as removal costs are incurred.
[26] Relieved as removal costs are incurred.
[27] Relieved when plant is decommissioned.
[28] Relieved when plant is decommissioned.
[29] See “February 2021 Severe Winter Weather Impacts in SPP” section of SWEPCo Rate Matters in Note 4 for additional information.
[30] See “February 2021 Severe Winter Weather Impacts in SPP” section of SWEPCo Rate Matters in Note 4 for additional information.
[31] Predominately pays a return due to the inclusion of Excess ADIT in rate base.
[32] Refunded over the period for which the related deferred income tax reverse, which is generally based on the expected life for the underlying assets. Excess ADIT Associated with Certain Depreciable Property is refunded over the remaining depreciable life of the underlying assets. Excess ADIT that is Not Subject to Rate Normalization Requirements were $228 million and $277 million for the years ended December 31, 2023 and 2022, respectively. The remaining balance of Excess ADIT that is Not Subject to Rate Normalization Requirements as of December 31, 2023 is to be refunded over 5 years.
[33] Predominately pays a return due to the inclusion of Excess ADIT in rate base.
[34] Refunded over the period for which the related deferred income tax reverse, which is generally based on the expected life for the underlying assets. Excess ADIT Associated with Certain Depreciable Property is refunded over the remaining depreciable life of the underlying assets.
[35] Predominately pays a return due to the inclusion of Excess ADIT in rate base.
[36] Refunded over the period for which the related deferred income tax reverse, which is generally based on the expected life for the underlying assets. Excess ADIT Associated with Certain Depreciable Property is refunded over the remaining depreciable life of the underlying assets. Excess ADIT that is Not Subject to Rate Normalization Requirements were $13 million and $16 million for the years ended December 31, 2023 and 2022, respectively. The remaining balance of Excess ADIT that is Not Subject to Rate Normalization Requirements as of December 31, 2023 is to be refunded over 5 years.
[37] Predominately pays a return due to the inclusion of Excess ADIT in rate base.
[38] Refunded over the period for which the related deferred income tax reverse, which is generally based on the expected life for the underlying assets. Excess ADIT Associated with Certain Depreciable Property is refunded over the remaining depreciable life of the underlying assets. Excess ADIT that is Not Subject to Rate Normalization Requirements were $35 million and $19 million for the years ended December 31, 2023 and 2022, respectively. The remaining balance of Excess ADIT that is Not Subject to Rate Normalization Requirements as of December 31, 2023 is to be refunded over 5 years.
[39] Refunded over the period for which the related deferred income tax reverse, which is generally based on the expected life for the underlying assets. Excess ADIT Associated with Certain Depreciable Property is refunded over the remaining depreciable life of the underlying assets. Excess ADIT that is Not Subject to Rate Normalization Requirements were $25 million and $42 million for the years ended December 31, 2023 and 2022, respectively. The remaining balance of Excess ADIT that is Not Subject to Rate Normalization Requirements as of December 31, 2023 is to be refunded over 5 years.
[40] Predominately pays a return due to the inclusion of Excess ADIT in rate base.
[41] Predominately pays a return due to the inclusion of Excess ADIT in rate base.
[42] Refunded over the period for which the related deferred income tax reverse, which is generally based on the expected life for the underlying assets. Excess ADIT Associated with Certain Depreciable Property is refunded over the remaining depreciable life of the underlying assets. Excess ADIT that is Not Subject to Rate Normalization Requirements were $132 million and $162 million for the years ended December 31, 2023 and 2022, respectively. The remaining balance of Excess ADIT that is Not Subject to Rate Normalization Requirements as of December 31, 2023 is to be refunded over 5 years.
[43] Refunded over the period for which the related deferred income tax reverse, which is generally based on the expected life for the underlying assets. Excess ADIT Associated with Certain Depreciable Property is refunded over the remaining depreciable life of the underlying assets. Excess ADIT that is Not Subject to Rate Normalization Requirements were $51 million and $21 million for the years ended December 31, 2023 and 2022, respectively. The remaining balance of Excess ADIT that is Not Subject to Rate Normalization Requirements as of December 31, 2023 is to be refunded over 1 year.
[44] Predominately pays a return due to the inclusion of Excess ADIT in rate base.
[45] Predominately pays a return due to the inclusion of Excess ADIT in rate base.
[46] Refunded over the period for which the related deferred income tax reverse, which is generally based on the expected life for the underlying assets. Excess ADIT Associated with Certain Depreciable Property is refunded over the remaining depreciable life of the underlying assets.
[47] Represents an income tax related regulatory asset, which is presented within net regulatory liabilities on the balance sheet.