Rate Matters Regulated Operations (Details) - USD ($) $ in Millions			3 Months Ended
		Apr. 30, 2024	Mar. 31, 2024	Dec. 31, 2023
Public Utilities, General Disclosures [Line Items]
Net Investment			$ 77,796.0	$ 76,693.4
Regulatory Assets, Noncurrent			5,034.1	5,092.4
Regulatory Assets, Current			550.3	514.0
AEP Texas Inc. [Member]
Public Utilities, General Disclosures [Line Items]
Net Investment			13,079.4	12,774.0
Regulatory Assets, Noncurrent			317.4	315.3
AEP Transmission Co [Member]
Public Utilities, General Disclosures [Line Items]
Net Investment			14,778.2	14,497.7
Regulatory Assets, Noncurrent			2.4	3.1
Appalachian Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Net Investment			13,052.9	12,931.5
Regulatory Assets, Noncurrent			1,107.4	1,155.1
Regulatory Assets, Current			148.4	155.4
Indiana Michigan Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Net Investment			7,651.2	7,629.0
Regulatory Assets, Noncurrent			498.2	406.3
Regulatory Assets, Current			3.8	14.8
Ohio Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Net Investment			9,467.4	9,299.9
Regulatory Assets, Noncurrent			416.6	455.0
Public Service Co Of Oklahoma [Member]
Public Utilities, General Disclosures [Line Items]
Net Investment			6,189.6	6,112.3
Regulatory Assets, Noncurrent			533.1	522.7
Regulatory Assets, Current			155.8	118.3
Public Service Co Of Oklahoma [Member] | Northeastern Plant, Unit 3 | Generating Units Probable of Abandonment [Member]
Public Utilities, General Disclosures [Line Items]
Net Investment			96.7
Accelerated Depreciation Regulatory Asset			168.9
Cost of Removal Regulatory Liability	[1]		$ 20.7
Expected Retirement Date	[2]		2026
Depreciation	[3]		$ 15.1
Southwestern Electric Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Net Investment			8,666.7	8,558.4
Regulatory Assets, Noncurrent			1,138.2	1,131.8
Net Under-Recovered Fuel Costs			72.0
Regulatory Assets, Current			166.3	170.8
Southwestern Electric Power Co [Member] | Dolet Hills Power Station [Member] | Louisiana Jurisdiction [Member] | Subsequent Event [Member]
Public Utilities, General Disclosures [Line Items]
Dolet Hills Prudency Disallowance		$ 14.0
Southwestern Electric Power Co [Member] | Dolet Hills Power Station and Related Fuel Operations
Public Utilities, General Disclosures [Line Items]
Share of Net Investment in Dolet Hills Power Station			86.0
Southwestern Electric Power Co [Member] | Dolet Hills Power Station and Related Fuel Operations | Arkansas
Public Utilities, General Disclosures [Line Items]
Recovery of 2021 Dolet Hills Fuel Costs			20.0
Southwestern Electric Power Co [Member] | Dolet Hills Power Station and Related Fuel Operations | Louisiana Jurisdiction [Member]
Public Utilities, General Disclosures [Line Items]
Recovery of 2021 Dolet Hills Fuel Costs			20.0
Approved Deferral of Dolet Hills Fuel Costs			35.0
Recommended Disallowance from Staff or Intervenors			55.0
ALJ Recommended Customer Refund			55.0
ALJ Recommended Denial of Recovery for Fuel Costs Deferral			35.0
Southwestern Electric Power Co [Member] | Dolet Hills Power Station and Related Fuel Operations | Louisiana Jurisdiction [Member] | Subsequent Event [Member]
Public Utilities, General Disclosures [Line Items]
Dolet Hills Fuel Disallowance		11.0
Remaining Dolet Fuel Reg Asset Recovered Over Three Years		$ 24.0
Southwestern Electric Power Co [Member] | Dolet Hills Power Station and Related Fuel Operations | Texas
Public Utilities, General Disclosures [Line Items]
Oxbow Mine Related Costs Recovery Request			48.0
Southwestern Electric Power Co [Member] | Pirkey Power Plant and Related Fuel Operations
Public Utilities, General Disclosures [Line Items]
Share of Net Investment in Pirkey Power Plant			185.0
Southwestern Electric Power Co [Member] | Pirkey Power Plant and Related Fuel Operations | Texas
Public Utilities, General Disclosures [Line Items]
Oxbow Mine Related Costs Recovery Request			33.0
Southwestern Electric Power Co [Member] | Pirkey Generating Station (Unit No. 1) | Texas
Public Utilities, General Disclosures [Line Items]
Net Investment			68.0
Southwestern Electric Power Co [Member] | Welsh Plant Unit 1 and 3 | Generating Units Probable of Abandonment [Member]
Public Utilities, General Disclosures [Line Items]
Net Investment			335.6
Accelerated Depreciation Regulatory Asset			135.7
Cost of Removal Regulatory Liability	[4]		$ 58.1
Expected Retirement Date	[5],[6]		2028
Depreciation	[3]		$ 39.2
Southwestern Electric Power Co [Member] | Dolet Hills Power Station | Arkansas
Public Utilities, General Disclosures [Line Items]
Asset Impairments and Other Related Charges			2.0
Southwestern Electric Power Co [Member] | Dolet Hills Power Station | Texas
Public Utilities, General Disclosures [Line Items]
Asset Impairments and Other Related Charges			12.0
Regulatory Assets Pending Final Regulatory Approval [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent			923.8	874.4
Regulatory Assets Pending Final Regulatory Approval [Member] | AEP Texas Inc. [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent			67.2	64.3
Regulatory Assets Pending Final Regulatory Approval [Member] | Appalachian Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent			128.9	125.5
Regulatory Assets Pending Final Regulatory Approval [Member] | Indiana Michigan Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent			54.7	33.2
Regulatory Assets Pending Final Regulatory Approval [Member] | Ohio Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent			23.6	23.6
Regulatory Assets Pending Final Regulatory Approval [Member] | Public Service Co Of Oklahoma [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent			103.8	88.7
Regulatory Assets Pending Final Regulatory Approval [Member] | Southwestern Electric Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent			461.6	444.9
Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Other Regulatory Assets Not Yet Being Recovered [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent			14.3	49.8
Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | February 2021 Severe Storm Fuel Costs
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent	[7]		90.8	97.2
Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Pirkey Power Plant Accelerated Depreciation
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent			121.0	114.4
Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Welsh Unit 1 and 3 Accelerated Depreciation
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent			135.7	125.6
Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Appalachian Power Co [Member] | Other Regulatory Assets Not Yet Being Recovered [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent			0.7	0.6
Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Indiana Michigan Power Co [Member] | Other Regulatory Assets Not Yet Being Recovered [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent			0.2	0.2
Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Southwestern Electric Power Co [Member] | Dolet Hills Power Station Accelerated Depreciation [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent	[8]		12.0	12.0
Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Southwestern Electric Power Co [Member] | Other Regulatory Assets Not Yet Being Recovered [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent			1.4	26.0
Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Southwestern Electric Power Co [Member] | February 2021 Severe Storm Fuel Costs
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent	[9]		90.8	97.2
Regulatory Assets, Current			37.0	37.0
Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Southwestern Electric Power Co [Member] | Pirkey Power Plant Accelerated Depreciation
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent			121.0	114.4
Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Southwestern Electric Power Co [Member] | Welsh Unit 1 and 3 Accelerated Depreciation
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent			135.7	125.6
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Storm Related Costs [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent			404.9	408.9
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Other Regulatory Assets Not Yet Being Recovered [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent			89.4	78.5
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | NOLC Costs [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent			67.7	0.0
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | AEP Texas Inc. [Member] | Storm Related Costs [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent			38.4	37.7
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | AEP Texas Inc. [Member] | Other Regulatory Assets Not Yet Being Recovered [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent			12.1	11.7
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | AEP Texas Inc. [Member] | Texas Retail Electric Provider Bad Debt Expense
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent			4.1	4.0
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | AEP Texas Inc. [Member] | Vegetation Management Programs
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent			5.2	5.2
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | AEP Texas Inc. [Member] | Line Inspection Costs [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent			7.4	5.7
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Appalachian Power Co [Member] | Plant Retirement Costs - Asset Retirement Obligation Costs [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent			25.9	25.9
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Appalachian Power Co [Member] | Storm Related Costs [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent			91.2	91.5
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Appalachian Power Co [Member] | Other Regulatory Assets Not Yet Being Recovered [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent			11.1	7.5
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Indiana Michigan Power Co [Member] | Storm Related Costs [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent			29.7	29.7
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Indiana Michigan Power Co [Member] | Other Regulatory Assets Not Yet Being Recovered [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent			4.6	3.3
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Indiana Michigan Power Co [Member] | NOLC Costs [Member] | Indiana [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent			20.2	0.0
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Ohio Power Co [Member] | Storm Related Costs [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent			23.6	23.6
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Public Service Co Of Oklahoma [Member] | Storm Related Costs [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent			88.8	88.5
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Public Service Co Of Oklahoma [Member] | Other Regulatory Assets Not Yet Being Recovered [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent			2.9	0.2
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Public Service Co Of Oklahoma [Member] | NOLC Costs [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent			12.1	0.0
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Southwestern Electric Power Co [Member] | Storm Related Costs [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent			51.4	56.0
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Southwestern Electric Power Co [Member] | Other Regulatory Assets Not Yet Being Recovered [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent			13.9	13.7
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Southwestern Electric Power Co [Member] | NOLC Costs [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent			$ 35.4	$ 0.0

[1] 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.

[2] Northeastern Plant, Unit 3 is currently being recovered through 2040.

[3] Represents the amount of annual depreciation that has been collected from customers over the prior 12-month period.

[4] 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.

[5] Represents projected retirement date of coal assets, units are being evaluated for conversion to natural gas after 2028.

[6] 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.

[7] Includes $37 million and $37 million of unrecovered winter storm fuel costs recorded as a current regulatory asset as of March 31, 2024 and December 31, 2023, respectively. See the “February 2021 Severe Winter Weather Impacts in SPP” section below for additional information.

[8] Amounts include the FERC jurisdiction

[9] Includes $37 million and $37 million of unrecovered winter storm fuel costs recorded as a current regulatory asset as of March 31, 2024 and December 31, 2023, respectively. See the “February 2021 Severe Winter Weather Impacts in SPP” section below for additional information.