Rate Matters Regulated Operations (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2022	Dec. 31, 2021
Public Utilities, General Disclosures [Line Items]
Net Investment		$ 67,878.0	$ 66,001.3
Regulatory Assets, Noncurrent		4,087.6	4,142.3
Regulatory Assets, Current		840.7	647.8
AEP Texas Inc. [Member]
Public Utilities, General Disclosures [Line Items]
Net Investment		10,842.1	10,635.4
Regulatory Assets, Noncurrent		277.7	275.2
AEP Transmission Co [Member]
Public Utilities, General Disclosures [Line Items]
Net Investment		12,163.8	11,935.7
Regulatory Assets, Noncurrent		6.4	8.5
Appalachian Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Net Investment		11,873.3	11,804.3
Regulatory Assets, Noncurrent		733.9	757.6
Regulatory Assets, Current		301.6	201.3
Indiana Michigan Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Net Investment		7,312.2	7,310.9
Regulatory Assets, Noncurrent		408.4	410.9
Regulatory Assets, Current		4.6	6.4
Ohio Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Net Investment		8,067.5	7,963.0
Regulatory Assets, Noncurrent		279.4	293.0
Public Service Co Of Oklahoma [Member]
Public Utilities, General Disclosures [Line Items]
Net Investment		5,404.5	4,802.8
Regulatory Assets, Noncurrent		1,042.0	1,037.4
Regulatory Assets, Current		219.2	194.6
Public Service Co Of Oklahoma [Member] | Northeastern Plant, Unit 3 | Generating Units Probable of Abandonment [Member]
Public Utilities, General Disclosures [Line Items]
Net Investment		159.1
Accelerated Depreciation Regulatory Asset		132.5
Cost of Removal Regulatory Liability	[1]	$ 20.1
Expected Retirement Date	[2]	2026
Depreciation	[3]	$ 14.9
Southwestern Electric Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Net Investment		8,087.3	7,400.1
Regulatory Assets, Noncurrent		962.3	1,005.3
Net Under-Recovered Fuel Costs		84.0
Regulatory Assets, Current		209.8	143.9
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		108.0
Recovery of 2021 Dolet Hills Fuel Costs		20.0
Approved Deferral of Dolet Hills Fuel Costs		30.0
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		207.0
Pirkey Power Plant and Sabine Unbilled Fixed Costs		87.0
Southwestern Electric Power Co [Member] | Pirkey Generating Station (Unit No. 1) | Generating Units Probable of Abandonment [Member]
Public Utilities, General Disclosures [Line Items]
Net Investment		99.6
Accelerated Depreciation Regulatory Asset		107.7
Cost of Removal Regulatory Liability		$ 39.3
Expected Retirement Date	[4]	2023
Depreciation	[3]	$ 13.4
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		467.2
Accelerated Depreciation Regulatory Asset		55.7
Cost of Removal Regulatory Liability	[5]	$ 58.6
Expected Retirement Date	[6]	2028
Depreciation	[3]	$ 37.3
Southwestern Electric Power Co [Member] | Welsh Plant Unit 2
Public Utilities, General Disclosures [Line Items]
Impairment Charge Welsh Plant, Unit 2		7.0
Southwestern Electric Power Co [Member] | Dolet Hills Power Station
Public Utilities, General Disclosures [Line Items]
Other Asset Impairment Charges		12.0
Regulatory Assets Pending Final Regulatory Approval [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent		912.9	1,048.6
Regulatory Assets Pending Final Regulatory Approval [Member] | AEP Texas Inc. [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent		45.8	41.2
Regulatory Assets Pending Final Regulatory Approval [Member] | Appalachian Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent		112.9	105.1
Regulatory Assets Pending Final Regulatory Approval [Member] | Indiana Michigan Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent		1.1	3.7
Regulatory Assets Pending Final Regulatory Approval [Member] | Ohio Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent		9.1	3.8
Regulatory Assets Pending Final Regulatory Approval [Member] | Public Service Co Of Oklahoma [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent		20.5	14.2
Regulatory Assets Pending Final Regulatory Approval [Member] | Southwestern Electric Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent		723.0	880.6
Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Plant Retirement Costs - Unrecovered Plant [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent		35.2	35.2
Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Dolet Hills Power Station Accelerated Depreciation [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent		72.2	72.3
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		10.5	9.2
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]	236.8	430.2
Regulatory Assets, Current		63.0	63.0
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		107.7	87.0
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		55.7	45.9
Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Dolet Hills Power Station Fuel Costs - Louisiana
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent		31.3	30.9
Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | AEP Texas Inc. [Member] | Mobile Generation Lease Payments
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent		1.3	0.0
Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Appalachian Power Co [Member] | COVID-19 - Virginia
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent		6.8	6.8
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		0.1	0.1
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		72.2	72.3
Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Southwestern Electric Power Co [Member] | Plant Retirement Costs - Unrecovered Plant, Louisiana
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent		35.2	35.2
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		2.3	2.4
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	[8]	236.8	430.2
Regulatory Assets, Current		63.0	63.0
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		107.7	87.0
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		55.7	45.9
Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Southwestern Electric Power Co [Member] | Dolet Hills Power Station Fuel Costs - Louisiana
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent		31.3	30.9
Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Southwestern Electric Power Co [Member] | Dolet Hills Power Station
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent		72.0
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | COVID-19
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent		11.9	11.2
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [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] | Storm Related Costs [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent		279.6	256.9
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		46.1	43.9
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | AEP Texas Inc. [Member] | COVID-19
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent		3.6	2.1
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		23.6	22.4
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		8.0	7.4
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	4.1
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] | 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		75.2	68.8
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		5.0	3.6
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Indiana Michigan Power Co [Member] | COVID-19
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent		0.2	1.7
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		0.8	1.9
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		9.1	3.8
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Public Service Co Of Oklahoma [Member] | COVID-19
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent		0.0	0.3
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		20.5	13.9
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Southwestern Electric Power Co [Member] | Asset Retirement Obligation - Louisiana [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent		10.6	10.3
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		20.0	18.4
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Southwestern Electric Power Co [Member] | Storm Related Costs - Louisiana
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent		$ 151.2	$ 148.0

[1] Includes Northeastern Plant, Unit 4, which was retired in 2016. Removal of Northeastern Plant, Unit 4, will be performed with 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] Pirkey Power Plant is currently being recovered through 2025 in the Louisiana jurisdiction and through 2045 in the Arkansas and Texas jurisdictions

[5] Includes Welsh Plant, Unit 2, which was retired in 2016. Removal of Welsh Plant, Unit 2, will be performed with Welsh Plant, Units 1 and 3, after retirement.

[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 $63 million and $63 million of unrecovered winter storm fuel costs recorded as a current regulatory asset as of March 31, 2022 and December 31, 2021, respectively.

[8] Includes $63 million and $63 million of unrecovered winter storm fuel costs recorded as a current regulatory asset as of March 31, 2022 and December 31, 2021, respectively.