Rate Matters West Companies (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021		Dec. 31, 2020	Dec. 31, 2019
Public Utilities, General Disclosures [Line Items]
Other Asset Impairment Charges	$ 11.6		$ 0.0	$ 156.4
Total Property, Plant and Equipment, Net	66,001.3	[1]	63,901.6
AEP Share of Independence Energy Connection Capital Costs	81.0
Noncurrent Regulatory Assets	4,142.3	[2]	3,527.0
AEP Texas Inc. [Member]
Public Utilities, General Disclosures [Line Items]
Other Asset Impairment Charges	0.0		0.0	32.5
Total Property, Plant and Equipment, Net	10,635.4		9,813.6
Noncurrent Regulatory Assets	275.2		266.8
Public Service Co Of Oklahoma [Member]
Public Utilities, General Disclosures [Line Items]
Total Property, Plant and Equipment, Net	4,802.8		4,320.0
Noncurrent Regulatory Assets	1,037.4		375.0
Southwestern Electric Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Other Asset Impairment Charges	11.6		0.0	0.0
Provision for Refund	(0.4)		(2.0)	$ (32.0)
Total Property, Plant and Equipment, Net	7,400.1		7,088.2
Noncurrent Regulatory Assets	1,005.3		$ 403.1
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	$ 298.0
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	$ 1,400.0
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
2016 Texas Base Rate Case [Member] | Southwestern Electric Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Requested Return on Equity	10.00%
Approved Return on Common Equity	9.60%
Requested Net Increase in Texas Annual Revenues	$ 69.0
Approved Net Increase in Texas Annual Revenues	50.0
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
2020 Texas Base Rate Case [Member] | Southwestern Electric Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Requested Annual Increase	$ 105.0
Approved Return on Common Equity	9.25%
Impairment Charge Total	$ 12.0
Requested Return on Equity	10.35%
Requested Net Annual Increase	$ 90.0
Amount of Increase Related to Annual Depreciation Expense	10.0
Amount of Increase Related to Storm Catastrophe Reserve	2.0
Requested Recovery of Dolet Hills Power Station	45.0
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
Amount of Increase Related to Vegetation Management	5.0
2020 Louisiana Base Rate Case [Member] | Southwestern Electric Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Requested Annual Increase	134.0
Staff Recommended Annual Rate Increase	$ 6.0
Requested Return on Equity	10.35%
Amount of Increase Related to Annual Depreciation Expense	$ 32.0
Revised Requested Annual Increase	$ 114.0
Staff Recommended Return on Common Equity	9.10%
Requested Annual Increase in Rebuttal	$ 95.0
2021 Oklahoma Base Rate Case | Public Service Co Of Oklahoma [Member]
Public Utilities, General Disclosures [Line Items]
Requested Annual Increase	$ 172.0
Approved Return on Common Equity	9.40%
Requested Return on Equity	10.00%
Amount of Increase Related to Annual Depreciation Expense	$ 57.0
Amount of Increase Related to SPP Expenses	31.0
Proposed Grid Transformation Plan	100.0
Revised Requested Annual Increase	128.0
Proposed Settlement Annual Rate Increase	$ 51.0
Proposed Settlement Agreement ROE	9.40%
Approved Annual Revenue Increase	$ 51.0
2021 Oklahoma Base Rate Case | Oklaunion Power Station Accelerated Depreciation [Member] | Public Service Co Of Oklahoma [Member]
Public Utilities, General Disclosures [Line Items]
Amount of Increase Related to Annual Depreciation Expense	45.0
2021 Arkansas Rate Case | Southwestern Electric Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Requested Annual Increase	85.0
Staff Recommended Annual Rate Increase	$ 47.0
Requested Return on Equity	10.35%
Amount of Increase Related to Annual Depreciation Expense	$ 14.0
Amount of Increase Related to SPP Expenses	$ 6.0
Staff Recommended Return on Common Equity	9.30%
Requested Annual Increase in Rebuttal	$ 81.0
Amount of Increase Related to North Central Wind Facilities	$ 41.0
Staff Recommended Debt Capital Structure	55.50%
Staff Recommended Equity Capital Structure	44.50%
Requested Debt Capital Structure	48.70%
Requested Equity Capital Structure	51.30%
February 2021 Severe Storm Fuel Costs | Public Service Co Of Oklahoma [Member]
Public Utilities, General Disclosures [Line Items]
Interim WACC	0.75%
Approved Carrying Charge	0.75%
February 2021 Severe Storm Fuel Costs | Public Service Co Of Oklahoma [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member]
Public Utilities, General Disclosures [Line Items]
Noncurrent Regulatory Assets	$ 679.0
February 2021 Severe Storm Fuel Costs | Southwestern Electric Power Co [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member]
Public Utilities, General Disclosures [Line Items]
Noncurrent Regulatory Assets	$ 430.0
February 2021 Severe Storm Fuel Costs | Southwestern Electric Power Co [Member] | Louisiana Jurisdiction [Member]
Public Utilities, General Disclosures [Line Items]
Interim WACC	3.25%
February 2021 Severe Storm Fuel Costs | Southwestern Electric Power Co [Member] | Louisiana Jurisdiction [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member]
Public Utilities, General Disclosures [Line Items]
Noncurrent Regulatory Assets	$ 148.0
February 2021 Severe Storm Fuel Costs | Southwestern Electric Power Co [Member] | Arkansas
Public Utilities, General Disclosures [Line Items]
Interim WACC	0.30%
Requested Weighted Average Cost of Capital	6.05%
Intervenor Recommended WACC	1.65%
February 2021 Severe Storm Fuel Costs | Southwestern Electric Power Co [Member] | Arkansas | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member]
Public Utilities, General Disclosures [Line Items]
Noncurrent Regulatory Assets	$ 103.0
February 2021 Severe Storm Fuel Costs | Southwestern Electric Power Co [Member] | Texas
Public Utilities, General Disclosures [Line Items]
Requested Weighted Average Cost of Capital	7.18%
February 2021 Severe Storm Fuel Costs | Southwestern Electric Power Co [Member] | Texas | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member]
Public Utilities, General Disclosures [Line Items]
Noncurrent Regulatory Assets	$ 179.0
2021 Louisiana Storm Cost Filing | Southwestern Electric Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Requested Deferred Storm Costs	145.0
Minimum [Member] | 2012 Texas Base Rate Case [Member] | Southwestern Electric Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Estimated Turk AFUDC Disallowance	80.0
Estimated Turk AFUDC Refunds	$ 0.0
Minimum [Member] | 2020 Louisiana Base Rate Case [Member] | Southwestern Electric Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Intervenor Recommended Return on Common Equity	9.35%
Minimum [Member] | 2021 Arkansas Rate Case | Southwestern Electric Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Intervenor Recommended Return on Common Equity	8.75%
Minimum [Member] | February 2021 Severe Storm Fuel Costs | Southwestern Electric Power Co [Member] | Texas
Public Utilities, General Disclosures [Line Items]
Intervenor Recommended WACC	0.82%
Maximum [Member] | 2012 Texas Base Rate Case [Member] | Southwestern Electric Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Estimated Turk AFUDC Disallowance	$ 100.0
Estimated Turk AFUDC Refunds	$ 160.0
Maximum [Member] | 2020 Louisiana Base Rate Case [Member] | Southwestern Electric Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Intervenor Recommended Return on Common Equity	9.80%
Maximum [Member] | 2021 Arkansas Rate Case | Southwestern Electric Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Intervenor Recommended Return on Common Equity	9.25%
Maximum [Member] | February 2021 Severe Storm Fuel Costs | Southwestern Electric Power Co [Member] | Texas
Public Utilities, General Disclosures [Line Items]
Intervenor Recommended WACC	1.625%

[1] Amount excludes $2.3 billion and $165 million for AEP and AEPTCo, respectively, of Property, Plant and Equipment - Net classified as Assets Held for Sale on the balance sheet. See “Disposition of KPCo and KTCo” section of Note 7 for additional information.

[2] 2021 amounts exclude $485 million of regulatory assets classified as Assets Held for Sale on the balance sheet. See “Disposition of KPCo and KTCo” section of Note 7 for additional information.