Rate Matters West Companies (Details) $ in Millions		3 Months Ended
	Apr. 30, 2024 USD ($)	Mar. 31, 2024 USD ($) MW	Dec. 31, 2023 USD ($)
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent		$ 5,034.1	$ 5,092.4
Regulatory Assets Pending Final Regulatory Approval [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent		923.8	874.4
Public Service Co Of Oklahoma [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent		533.1	522.7
Public Service Co Of Oklahoma [Member] | Regulatory Assets Pending Final Regulatory Approval [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent		103.8	88.7
Southwestern Electric Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent		1,138.2	1,131.8
Southwestern Electric Power Co [Member] | Regulatory Assets Pending Final Regulatory Approval [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent		461.6	444.9
AEP Texas Inc. [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent		317.4	315.3
AEP Texas Inc. [Member] | Regulatory Assets Pending Final Regulatory Approval [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent		$ 67.2	64.3
ETT Interim Transmission Rates [Member]
Public Utilities, General Disclosures [Line Items]
Parent Ownership Interest In ETT		50.00%
AEP Share Of ETT Cumulative Revenues Subject To Review		$ 1,700.0
February 2021 Severe Storm Fuel Costs | Southwestern Electric Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent		233.9	253.3
February 2021 Severe Storm Fuel Costs | Southwestern Electric Power Co [Member] | Arkansas
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent		$ 48.6	54.2
Remaining Recovery Period		6 years
February 2021 Severe Storm Fuel Costs | Southwestern Electric Power Co [Member] | Louisiana Jurisdiction [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent		$ 90.8	97.2
February 2021 Severe Storm Fuel Costs | Southwestern Electric Power Co [Member] | Texas
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent		$ 94.5	$ 101.9
Approved Carrying Charge		1.65%
Remaining Recovery Period		5 years
2012 Texas Base Rate Case [Member] | Southwestern Electric Power Co [Member]
Public Utilities, General Disclosures [Line Items]
2013 Reversal Of Previously Recorded Regulatory Disallowances		$ 114.0
Estimated Reduced Annual Revenues		15.0
Turk AFUDC Disallowance		86.0
2012 Texas Base Rate Case [Member] | Southwestern Electric Power Co [Member] | Minimum [Member]
Public Utilities, General Disclosures [Line Items]
Estimated Turk AFUDC Refunds		0.0
2012 Texas Base Rate Case [Member] | Southwestern Electric Power Co [Member] | Minimum [Member] | Subsequent Event [Member]
Public Utilities, General Disclosures [Line Items]
Recommended Customer Refunds	$ 149.0
Recommended Refund Period	18 months
2012 Texas Base Rate Case [Member] | Southwestern Electric Power Co [Member] | Maximum [Member]
Public Utilities, General Disclosures [Line Items]
Estimated Turk AFUDC Refunds		200.0
2012 Texas Base Rate Case [Member] | Southwestern Electric Power Co [Member] | Maximum [Member] | Subsequent Event [Member]
Public Utilities, General Disclosures [Line Items]
Recommended Customer Refunds	$ 197.0
Recommended Refund Period	48 months
2016 Texas Base Rate Case [Member] | Southwestern Electric Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Requested Net Increase in Texas Annual Revenues		69.0
Approved Net Increase in Texas Annual Revenues		$ 50.0
Approved Return on Common Equity		9.60%
Approved Additional Vegetation Management Expenses		$ 2.0
Impairment Charge Total		19.0
Impairment Charge Welsh Plant, Unit 2		7.0
Impairment Charge Disallowed Plant Investments		12.0
Additional Revenues Recognized to be Surcharged to Customers		32.0
Additional Recognized Expenses Consisting Primarily of Depreciation and Vegetation Management		$ 7.0
Requested Return on Equity		10.00%
2020 Texas Base Rate Case [Member] | Southwestern Electric Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Approved Return on Common Equity		9.25%
Impairment Charge Total		$ 12.0
Requested Annual Increase		$ 105.0
Requested Return on Equity		10.35%
Requested Net Annual Increase		$ 90.0
Revised Requested Annual Increase		100.0
Revised Requested Net Annual Increase		85.0
Approved Annual Revenue Increase		39.0
Amount of Approved Increase Related to Vegetation Management		5.0
Amount of Approved Increase Related to Storm Catastrophe Reserve		$ 2.0
2021 Louisiana Storm Cost Filing | Southwestern Electric Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Interim WACC		3.125%
Approved Deferred Storm Costs		$ 150.0
AEP Texas Interim Transmission and Distribution Rates [Member] | AEP Texas Inc. [Member]
Public Utilities, General Disclosures [Line Items]
AEP Texas Cumulative Revenues Subject to Review		$ 1,100.0
2024 AEP Texas Base Rate Case [Member] | AEP Texas Inc. [Member]
Public Utilities, General Disclosures [Line Items]
Requested Return on Equity		10.60%
Requested Debt Capital Structure		55.00%
Requested Equity Capital Structure		45.00%
Requested Annual Base Rate Increase		$ 164.0
2024 Oklahoma Base Rate Case [Member] | Public Service Co Of Oklahoma [Member]
Public Utilities, General Disclosures [Line Items]
Requested Return on Equity		10.80%
Requested Debt Capital Structure		48.90%
Requested Equity Capital Structure		51.10%
Requested Net Increase in Oklahoma Annual Revenues		$ 218.0
Wind Generation MWs | MW		155