Derivatives and Hedging (Details) gal in Millions, MWh in Millions, MMBTU in Millions		12 Months Ended
		Dec. 31, 2021 USD ($) MWh MMBTU gal		Dec. 31, 2020 USD ($) MWh MMBTU gal		Dec. 31, 2019 USD ($)
Cash Collateral Netting
Cash Collateral Received Netted Against Risk Management Assets		$ 263,000,000		$ 3,000,000
Cash Collateral Paid Netted Against Risk Management Liabilities		3,000,000		7,000,000
Fair Value of Derivative Instruments
Current Risk Management Assets		194,400,000		94,700,000
Derivative Asset, Noncurrent		267,000,000.0		242,200,000
Total Assets		461,400,000		336,900,000
Current Risk Management Liabilities		75,400,000		78,800,000
Derivative Liability, Noncurrent		230,300,000		232,800,000
Total Liabilities		305,700,000		311,600,000
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		324,000,000.0		116,900,000		$ 125,000,000.0
Impact of Fair Value Hedges on the Balance Sheet
Carrying Amount of Hedged Asset (Liability)	[1],[2]	(952,300,000)		(995,900,000)
Cumulative Fair Value Hedging Adjustment in the Carrying Amount of the Hedged Asset (Liability)	[1],[2]	(8,500,000)		(51,700,000)
Impact of Cash Flow Hedges on the Balance Sheet
Gain (Loss) on Fair Value Hedging Instruments	[3]	(35,500,000)		41,100,000		31,900,000
Gain (Loss) on Fair Value Portion of Long Term Debt	[3]	35,500,000		(41,100,000)		(31,900,000)
Collateral Triggering Events
Liabilities for Contracts with Cross Default Provisions Prior to Contractural Netting Arrangements		159,500,000		188,400,000
Amount of Cash Collateral Posted		0		0
Additional Settlement Liability if Cross Default Provision is Triggered		115,400,000		169,200,000
Derivatives and Hedging (Textuals)
Hedged Liability, Discontinued Fair Value Hedge, Cumulative Increase (Decrease)		(46,000,000)		(53,000,000)
Notional Amount of a Discontinued Hedge		500,000,000
Deferred (Gain) Loss on Discontinuation of Fair Value Hedge		57,000,000
Credit Downgrade Trigger Exposure		9,000,000
Assets Held for Sale		2,919,700,000		0
Liabilities Held for Sale		1,880,900,000		0
Investment in ChargePoint
Derivatives and Hedging (Textuals)
Equity Method Investments, Fair Value Disclosure		29,000,000
Unrealized Gain (Loss) on Investments		26,000,000
AEP Texas Inc. [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		2,000,000.0		(1,000,000.0)		300,000
AEP Transmission Co [Member]
Derivatives and Hedging (Textuals)
Assets Held for Sale		167,900,000		0
Liabilities Held for Sale		27,600,000		0
Appalachian Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets		42,000,000.0		22,400,000
Total Assets				22,500,000
Total Liabilities				4,700,000
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		55,300,000		21,300,000		4,100,000
Collateral Triggering Events
Liabilities for Contracts with Cross Default Provisions Prior to Contractural Netting Arrangements		500,000		4,300,000
Amount of Cash Collateral Posted		0		0
Additional Settlement Liability if Cross Default Provision is Triggered		300,000		3,500,000
Indiana Michigan Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets		3,300,000		3,600,000
Current Risk Management Liabilities		5,000,000.0		100,000
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		(18,200,000)		12,000,000.0		25,200,000
Collateral Triggering Events
Liabilities for Contracts with Cross Default Provisions Prior to Contractural Netting Arrangements		300,000		500,000
Amount of Cash Collateral Posted		0		0
Additional Settlement Liability if Cross Default Provision is Triggered		200,000		100,000
Ohio Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Liabilities		6,700,000		8,700,000
Derivative Liability, Noncurrent		85,800,000		101,600,000
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		11,100,000		5,000,000.0		6,000,000.0
Public Service Co Of Oklahoma [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets		12,100,000		10,300,000
Current Risk Management Liabilities		3,700,000		0
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		46,000,000.0		38,600,000		35,600,000
Collateral Triggering Events
Liabilities for Contracts with Cross Default Provisions Prior to Contractural Netting Arrangements		1,700,000
Amount of Cash Collateral Posted		0
Additional Settlement Liability if Cross Default Provision is Triggered		1,700,000
Southwestern Electric Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets		9,800,000		3,200,000
Current Risk Management Liabilities		2,100,000		700,000
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		41,500,000		21,000,000.0		25,000,000.0
Collateral Triggering Events
Liabilities for Contracts with Cross Default Provisions Prior to Contractural Netting Arrangements		2,700,000		1,800,000
Amount of Cash Collateral Posted		0		0
Additional Settlement Liability if Cross Default Provision is Triggered		2,700,000		1,800,000
Risk Management Contracts [Member]
Fair Value of Derivative Instruments
Total Assets	[5]	239,800,000	[4],[6]	322,100,000	[7]
Total Liabilities	[5]	254,700,000	[6],[8]	218,900,000	[7]
Derivatives and Hedging (Textuals)
Assets Held for Sale		6,000,000
Liabilities Held for Sale		100,000
Risk Management Contracts [Member] | AEP Texas Inc. [Member]
Fair Value of Derivative Instruments
Total Assets		0	[5]	0
Risk Management Contracts [Member] | Appalachian Power Co [Member]
Fair Value of Derivative Instruments
Total Assets	[5],[9]	42,000,000.0		20,100,000
Total Liabilities	[5],[9]	800,000		1,300,000
Risk Management Contracts [Member] | Indiana Michigan Power Co [Member]
Fair Value of Derivative Instruments
Total Assets	[5],[9]	3,300,000		3,700,000
Total Liabilities	[5],[9]	5,000,000.0		200,000
Risk Management Contracts [Member] | Ohio Power Co [Member]
Fair Value of Derivative Instruments
Total Assets	[5],[9]	0		0
Total Liabilities	[5],[9]	92,500,000		110,300,000
Risk Management Contracts [Member] | Public Service Co Of Oklahoma [Member]
Fair Value of Derivative Instruments
Total Assets	[5],[9]	12,100,000		10,300,000
Total Liabilities	[5],[9]	3,700,000
Risk Management Contracts [Member] | Southwestern Electric Power Co [Member]
Fair Value of Derivative Instruments
Total Assets	[5],[9]	10,900,000		3,200,000
Total Liabilities	[5],[9]	2,100,000		1,700,000
Commodity [Member]
Impact of Cash Flow Hedges on the Balance Sheet
AOCI Gain (Loss) Net of Tax		163,700,000		(60,600,000)
Portion Expected to be Reclassified to Net Income During the Next Twelve Months		$ 106,700,000		(27,100,000)
Derivatives and Hedging (Textuals)
Maximum Length of Time Hedged in Price Risk Cash Flow Hedge		111 months
Cross Default Provisions Maximum Third Party Obligation Amount		$ 50,000,000
Commodity [Member] | Risk Management Contracts [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[11]	513,400,000	[10]	239,100,000
Derivative Asset, Noncurrent	[11]	370,500,000		275,900,000
Total Assets	[11]	883,900,000		515,000,000.0
Current Risk Management Liabilities	[11]	395,700,000	[12]	193,000,000.0
Derivative Liability, Noncurrent	[11]	243,900,000		222,200,000
Total Liabilities	[11]	639,600,000		415,200,000
Total MTM Derivative Contract Net Assets (Liabilities)	[11]	244,300,000		99,800,000
Commodity [Member] | Risk Management Contracts [Member] | AEP Texas Inc. [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[11]	600,000		400,000
Derivative Asset, Noncurrent	[11]	0		0
Total Assets	[11]	600,000		400,000
Current Risk Management Liabilities	[11]	0		0
Derivative Liability, Noncurrent	[11]	0		0
Total Liabilities	[11]	0		0
Total MTM Derivative Contract Net Assets (Liabilities)	[11]	600,000		400,000
Commodity [Member] | Risk Management Contracts [Member] | Appalachian Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[11]	47,500,000		38,800,000
Derivative Asset, Noncurrent	[11]	200,000		700,000
Total Assets	[11]	47,700,000		39,500,000
Current Risk Management Liabilities	[11]	7,200,000		19,700,000
Derivative Liability, Noncurrent	[11]	200,000		600,000
Total Liabilities	[11]	7,400,000		20,300,000
Total MTM Derivative Contract Net Assets (Liabilities)	[11]	40,300,000		19,200,000
Commodity [Member] | Risk Management Contracts [Member] | Indiana Michigan Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[11]	11,100,000		17,200,000
Derivative Asset, Noncurrent	[11]	200,000		500,000
Total Assets	[11]	11,300,000		17,700,000
Current Risk Management Liabilities	[11]	14,800,000		12,100,000
Derivative Liability, Noncurrent	[11]	200,000		400,000
Total Liabilities	[11]	15,000,000.0		12,500,000
Total MTM Derivative Contract Net Assets (Liabilities)	[11]	(3,700,000)		5,200,000
Commodity [Member] | Risk Management Contracts [Member] | Ohio Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[11]	500,000		300,000
Derivative Asset, Noncurrent	[11]	0		0
Total Assets	[11]	500,000		300,000
Current Risk Management Liabilities	[11]	6,700,000		8,700,000
Derivative Liability, Noncurrent	[11]	85,800,000		101,600,000
Total Liabilities	[11]	92,500,000		110,300,000
Total MTM Derivative Contract Net Assets (Liabilities)	[11]	(92,000,000.0)		(110,000,000.0)
Commodity [Member] | Risk Management Contracts [Member] | Public Service Co Of Oklahoma [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[11]	12,400,000		10,500,000
Derivative Asset, Noncurrent	[11]	0		0
Total Assets	[11]	12,400,000		10,500,000
Current Risk Management Liabilities	[11]	3,700,000		0
Derivative Liability, Noncurrent	[11]	0		0
Total Liabilities	[11]	3,700,000		0
Total MTM Derivative Contract Net Assets (Liabilities)	[11]	8,700,000		10,500,000
Commodity [Member] | Risk Management Contracts [Member] | Southwestern Electric Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[11]	10,100,000		3,400,000
Derivative Asset, Noncurrent	[11]	1,100,000		0
Total Assets	[11]	11,200,000		3,400,000
Current Risk Management Liabilities	[11]	2,100,000		700,000
Derivative Liability, Noncurrent	[11]	0		1,000,000.0
Total Liabilities	[11]	2,100,000		1,700,000
Total MTM Derivative Contract Net Assets (Liabilities)	[11]	9,100,000		1,700,000
Commodity [Member] | Hedging Contracts [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[11]	176,000,000.0		21,100,000
Derivative Asset, Noncurrent	[11]	89,100,000		18,000,000.0
Total Assets	[11]	265,100,000		39,100,000
Current Risk Management Liabilities	[11]	40,900,000		54,400,000
Derivative Liability, Noncurrent	[11]	16,700,000		60,100,000
Total Liabilities	[11]	57,600,000		114,500,000
Total MTM Derivative Contract Net Assets (Liabilities)	[11]	207,500,000		(75,400,000)
Interest Rate [Member]
Commodity
Derivative, Notional Amount		950,000,000.0		1,150,000,000
Impact of Cash Flow Hedges on the Balance Sheet
AOCI Gain (Loss) Net of Tax		(21,300,000)		(47,500,000)
Portion Expected to be Reclassified to Net Income During the Next Twelve Months		$ (3,300,000)		(5,700,000)
Derivatives and Hedging (Textuals)
Maximum Length of Time Hedged in Price Risk Cash Flow Hedge		108 months
Interest Rate [Member] | AEP Texas Inc. [Member]
Commodity
Derivative, Notional Amount		$ 0		0
Impact of Cash Flow Hedges on the Balance Sheet
AOCI Gain (Loss) Net of Tax		(1,300,000)		(2,300,000)
Portion Expected to be Reclassified to Net Income During the Next Twelve Months		(1,100,000)		(1,100,000)
Interest Rate [Member] | Appalachian Power Co [Member]
Commodity
Derivative, Notional Amount		0		200,000,000.0
Impact of Cash Flow Hedges on the Balance Sheet
AOCI Gain (Loss) Net of Tax		7,500,000		(800,000)
Portion Expected to be Reclassified to Net Income During the Next Twelve Months		800,000		400,000
Interest Rate [Member] | Indiana Michigan Power Co [Member]
Commodity
Derivative, Notional Amount		0		0
Impact of Cash Flow Hedges on the Balance Sheet
AOCI Gain (Loss) Net of Tax		(6,700,000)		(8,300,000)
Portion Expected to be Reclassified to Net Income During the Next Twelve Months		(1,600,000)		(1,600,000)
Interest Rate [Member] | Ohio Power Co [Member]
Commodity
Derivative, Notional Amount		0		0
Interest Rate [Member] | Public Service Co Of Oklahoma [Member]
Commodity
Derivative, Notional Amount		0		0
Impact of Cash Flow Hedges on the Balance Sheet
AOCI Gain (Loss) Net of Tax		0		100,000
Portion Expected to be Reclassified to Net Income During the Next Twelve Months		0		100,000
Interest Rate [Member] | Southwestern Electric Power Co [Member]
Commodity
Derivative, Notional Amount		0		0
Impact of Cash Flow Hedges on the Balance Sheet
AOCI Gain (Loss) Net of Tax		1,200,000		(300,000)
Portion Expected to be Reclassified to Net Income During the Next Twelve Months		100,000		(1,500,000)
Interest Rate [Member] | Hedging Contracts [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[11]	1,200,000		5,000,000.0
Derivative Asset, Noncurrent	[11]	0		0
Total Assets	[11]	1,200,000		5,000,000.0
Current Risk Management Liabilities	[11]	0		3,400,000
Derivative Liability, Noncurrent	[11]	38,100,000		4,100,000
Total Liabilities	[11]	38,100,000		7,500,000
Total MTM Derivative Contract Net Assets (Liabilities)	[11]	(36,900,000)		(2,500,000)
Interest Rate [Member] | Hedging Contracts [Member] | Appalachian Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets				2,400,000
Derivative Asset, Noncurrent				0
Total Assets				2,400,000
Current Risk Management Liabilities				3,400,000
Derivative Liability, Noncurrent				0
Total Liabilities				3,400,000
Total MTM Derivative Contract Net Assets (Liabilities)				(1,000,000.0)
Gross Amounts of Risk Management Assets/Liabilities Recognized [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets		690,600,000	[10]	265,200,000
Derivative Asset, Noncurrent		459,600,000		293,900,000
Total Assets		1,150,200,000		559,100,000
Current Risk Management Liabilities		436,600,000	[12]	250,800,000
Derivative Liability, Noncurrent		298,700,000		286,400,000
Total Liabilities		735,300,000		537,200,000
Total MTM Derivative Contract Net Assets (Liabilities)		414,900,000		21,900,000
Gross Amounts of Risk Management Assets/Liabilities Recognized [Member] | Appalachian Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets				41,200,000
Derivative Asset, Noncurrent				700,000
Total Assets				41,900,000
Current Risk Management Liabilities				23,100,000
Derivative Liability, Noncurrent				600,000
Total Liabilities				23,700,000
Total MTM Derivative Contract Net Assets (Liabilities)				18,200,000
Gross Amounts Offset in the Statement of Financial Position [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[13]	(496,200,000)	[10]	(170,500,000)
Derivative Asset, Noncurrent	[13]	(192,600,000)		(51,700,000)
Total Assets	[13]	(688,800,000)		(222,200,000)
Current Risk Management Liabilities	[13]	(361,200,000)	[12]	(172,000,000.0)
Derivative Liability, Noncurrent	[13]	(68,400,000)		(53,600,000)
Total Liabilities	[13]	(429,600,000)		(225,600,000)
Total MTM Derivative Contract Net Assets (Liabilities)	[13]	(259,200,000)		3,400,000
Gross Amounts Offset in the Statement of Financial Position [Member] | AEP Texas Inc. [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[13]	(600,000)		(400,000)
Derivative Asset, Noncurrent	[13]	0		0
Total Assets	[13]	(600,000)		(400,000)
Current Risk Management Liabilities	[13]	0		0
Derivative Liability, Noncurrent	[13]	0		0
Total Liabilities	[13]	0		0
Total MTM Derivative Contract Net Assets (Liabilities)	[13]	(600,000)		(400,000)
Gross Amounts Offset in the Statement of Financial Position [Member] | Appalachian Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[13]	(5,500,000)		(18,800,000)
Derivative Asset, Noncurrent	[13]	(200,000)		(600,000)
Total Assets	[13]	(5,700,000)		(19,400,000)
Current Risk Management Liabilities	[13]	(6,400,000)		(18,500,000)
Derivative Liability, Noncurrent	[13]	(200,000)		(500,000)
Total Liabilities	[13]	(6,600,000)		(19,000,000.0)
Total MTM Derivative Contract Net Assets (Liabilities)	[13]	900,000		(400,000)
Gross Amounts Offset in the Statement of Financial Position [Member] | Indiana Michigan Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[13]	(7,800,000)		(13,600,000)
Derivative Asset, Noncurrent	[13]	(200,000)		(400,000)
Total Assets	[13]	(8,000,000.0)		(14,000,000.0)
Current Risk Management Liabilities	[13]	(9,800,000)		(12,000,000.0)
Derivative Liability, Noncurrent	[13]	(200,000)		(300,000)
Total Liabilities	[13]	(10,000,000.0)		(12,300,000)
Total MTM Derivative Contract Net Assets (Liabilities)	[13]	2,000,000.0		(1,700,000)
Gross Amounts Offset in the Statement of Financial Position [Member] | Ohio Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[13]	(500,000)		(300,000)
Derivative Asset, Noncurrent	[13]	0		0
Total Assets	[13]	(500,000)		(300,000)
Current Risk Management Liabilities	[13]	0		0
Derivative Liability, Noncurrent	[13]	0		0
Total Liabilities	[13]	0		0
Total MTM Derivative Contract Net Assets (Liabilities)	[13]	(500,000)		(300,000)
Gross Amounts Offset in the Statement of Financial Position [Member] | Public Service Co Of Oklahoma [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[13]	(300,000)		(200,000)
Derivative Asset, Noncurrent	[13]	0		0
Total Assets	[13]	(300,000)		(200,000)
Current Risk Management Liabilities	[13]	0		0
Derivative Liability, Noncurrent	[13]	0		0
Total Liabilities	[13]	0		0
Total MTM Derivative Contract Net Assets (Liabilities)	[13]	(300,000)		(200,000)
Gross Amounts Offset in the Statement of Financial Position [Member] | Southwestern Electric Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[13]	(300,000)		(200,000)
Derivative Asset, Noncurrent	[13]	0		0
Total Assets	[13]	(300,000)		(200,000)
Current Risk Management Liabilities	[13]	0		0
Derivative Liability, Noncurrent	[13]	0		0
Total Liabilities	[13]	0		0
Total MTM Derivative Contract Net Assets (Liabilities)	[13]	(300,000)		(200,000)
Net Amounts of Assets/Liabilities Presented in the Statement of Financial Position [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[14]	194,400,000	[10]	94,700,000
Derivative Asset, Noncurrent	[14]	267,000,000.0		242,200,000
Total Assets	[14]	461,400,000		336,900,000
Current Risk Management Liabilities	[14]	75,400,000	[12]	78,800,000
Derivative Liability, Noncurrent	[14]	230,300,000		232,800,000
Total Liabilities	[14]	305,700,000		311,600,000
Total MTM Derivative Contract Net Assets (Liabilities)	[14]	155,700,000		25,300,000
Net Amounts of Assets/Liabilities Presented in the Statement of Financial Position [Member] | AEP Texas Inc. [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[14]	0		0
Derivative Asset, Noncurrent	[14]	0		0
Total Assets	[14]	0		0
Current Risk Management Liabilities	[14]	0		0
Derivative Liability, Noncurrent	[14]	0		0
Total Liabilities	[14]	0		0
Total MTM Derivative Contract Net Assets (Liabilities)	[14]	0		0
Net Amounts of Assets/Liabilities Presented in the Statement of Financial Position [Member] | Appalachian Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[14]	42,000,000.0		22,400,000
Derivative Asset, Noncurrent	[14]	0		100,000
Total Assets	[14]	42,000,000.0		22,500,000
Current Risk Management Liabilities	[14]	800,000		4,600,000
Derivative Liability, Noncurrent	[14]	0		100,000
Total Liabilities	[14]	800,000		4,700,000
Total MTM Derivative Contract Net Assets (Liabilities)	[14]	41,200,000		17,800,000
Net Amounts of Assets/Liabilities Presented in the Statement of Financial Position [Member] | Indiana Michigan Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[14]	3,300,000		3,600,000
Derivative Asset, Noncurrent	[14]	0		100,000
Total Assets	[14]	3,300,000		3,700,000
Current Risk Management Liabilities	[14]	5,000,000.0		100,000
Derivative Liability, Noncurrent	[14]	0		100,000
Total Liabilities	[14]	5,000,000.0		200,000
Total MTM Derivative Contract Net Assets (Liabilities)	[14]	(1,700,000)		3,500,000
Net Amounts of Assets/Liabilities Presented in the Statement of Financial Position [Member] | Ohio Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[14]	0		0
Derivative Asset, Noncurrent	[14]	0		0
Total Assets	[14]	0		0
Current Risk Management Liabilities	[14]	6,700,000		8,700,000
Derivative Liability, Noncurrent	[14]	85,800,000		101,600,000
Total Liabilities	[14]	92,500,000		110,300,000
Total MTM Derivative Contract Net Assets (Liabilities)	[14]	(92,500,000)		(110,300,000)
Net Amounts of Assets/Liabilities Presented in the Statement of Financial Position [Member] | Public Service Co Of Oklahoma [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[14]	12,100,000		10,300,000
Derivative Asset, Noncurrent	[14]	0		0
Total Assets	[14]	12,100,000		10,300,000
Current Risk Management Liabilities	[14]	3,700,000		0
Derivative Liability, Noncurrent	[14]	0		0
Total Liabilities	[14]	3,700,000		0
Total MTM Derivative Contract Net Assets (Liabilities)	[14]	8,400,000		10,300,000
Net Amounts of Assets/Liabilities Presented in the Statement of Financial Position [Member] | Southwestern Electric Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[14]	9,800,000		3,200,000
Derivative Asset, Noncurrent	[14]	1,100,000		0
Total Assets	[14]	10,900,000		3,200,000
Current Risk Management Liabilities	[14]	2,100,000		700,000
Derivative Liability, Noncurrent	[14]	0		1,000,000.0
Total Liabilities	[14]	2,100,000		1,700,000
Total MTM Derivative Contract Net Assets (Liabilities)	[14]	8,800,000		$ 1,500,000
Held For Sale [Member]
Derivatives and Hedging (Textuals)
Assets Held for Sale		6,000,000
Liabilities Held for Sale		$ 100,000
Power [Member]
Commodity
Derivative, Energy Notional Amount | MWh		287.9		331.3
Power [Member] | AEP Texas Inc. [Member]
Commodity
Derivative, Energy Notional Amount | MWh		0.0		0.0
Power [Member] | Appalachian Power Co [Member]
Commodity
Derivative, Energy Notional Amount | MWh		33.1		46.9
Power [Member] | Indiana Michigan Power Co [Member]
Commodity
Derivative, Energy Notional Amount | MWh		13.6		19.7
Power [Member] | Ohio Power Co [Member]
Commodity
Derivative, Energy Notional Amount | MWh		2.7		3.0
Power [Member] | Public Service Co Of Oklahoma [Member]
Commodity
Derivative, Energy Notional Amount | MWh		11.9		11.9
Power [Member] | Southwestern Electric Power Co [Member]
Commodity
Derivative, Energy Notional Amount | MWh		3.4		4.0
Natural Gas [Member]
Commodity
Derivative, Energy Notional Amount | MMBTU		34.1		26.9
Natural Gas [Member] | AEP Texas Inc. [Member]
Commodity
Derivative, Energy Notional Amount | MMBTU		0.0		0.0
Natural Gas [Member] | Appalachian Power Co [Member]
Commodity
Derivative, Energy Notional Amount | MMBTU		0.0		0.0
Natural Gas [Member] | Indiana Michigan Power Co [Member]
Commodity
Derivative, Energy Notional Amount | MMBTU		0.0		0.0
Natural Gas [Member] | Ohio Power Co [Member]
Commodity
Derivative, Energy Notional Amount | MMBTU		0.0		0.0
Natural Gas [Member] | Public Service Co Of Oklahoma [Member]
Commodity
Derivative, Energy Notional Amount | MMBTU		1.3		0.0
Natural Gas [Member] | Southwestern Electric Power Co [Member]
Commodity
Derivative, Energy Notional Amount | MMBTU		5.1		7.9
Heating Oil and Gasoline [Member]
Commodity
Derivative, Volume Notional Amount | gal		7.4		6.9
Heating Oil and Gasoline [Member] | AEP Texas Inc. [Member]
Commodity
Derivative, Volume Notional Amount | gal		1.9		1.8
Heating Oil and Gasoline [Member] | Appalachian Power Co [Member]
Commodity
Derivative, Volume Notional Amount | gal		1.1		1.1
Heating Oil and Gasoline [Member] | Indiana Michigan Power Co [Member]
Commodity
Derivative, Volume Notional Amount | gal		0.7		0.6
Heating Oil and Gasoline [Member] | Ohio Power Co [Member]
Commodity
Derivative, Volume Notional Amount | gal		1.5		1.4
Heating Oil and Gasoline [Member] | Public Service Co Of Oklahoma [Member]
Commodity
Derivative, Volume Notional Amount | gal		0.8		0.7
Heating Oil and Gasoline [Member] | Southwestern Electric Power Co [Member]
Commodity
Derivative, Volume Notional Amount | gal		1.0		0.9
Interest Rate Contract [Member]
Commodity
Derivative, Notional Amount		$ 116,500,000		$ 129,800,000
Interest Rate Contract [Member] | AEP Texas Inc. [Member]
Commodity
Derivative, Notional Amount		0		0
Interest Rate Contract [Member] | Appalachian Power Co [Member]
Commodity
Derivative, Notional Amount		0		0
Interest Rate Contract [Member] | Indiana Michigan Power Co [Member]
Commodity
Derivative, Notional Amount		0		0
Interest Rate Contract [Member] | Ohio Power Co [Member]
Commodity
Derivative, Notional Amount		0		0
Interest Rate Contract [Member] | Public Service Co Of Oklahoma [Member]
Commodity
Derivative, Notional Amount		0		0
Interest Rate Contract [Member] | Southwestern Electric Power Co [Member]
Commodity
Derivative, Notional Amount		0		0
Warrants Held in Investee [Member]
Fair Value of Derivative Instruments
Total Assets		15,000,000		32,000,000
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		(17,000,000)		32,000,000
Derivatives and Hedging (Textuals)
Cost of Investment in Privately Held Investee				8,000,000
Vertically Integrated Utilities Revenues [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		(600,000)		800,000		700,000
Vertically Integrated Utilities Revenues [Member] | AEP Texas Inc. [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		0		0		0
Vertically Integrated Utilities Revenues [Member] | Appalachian Power Co [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		0		0		0
Vertically Integrated Utilities Revenues [Member] | Indiana Michigan Power Co [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		0		0		0
Vertically Integrated Utilities Revenues [Member] | Ohio Power Co [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		0		0		0
Vertically Integrated Utilities Revenues [Member] | Public Service Co Of Oklahoma [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		0		0		0
Vertically Integrated Utilities Revenues [Member] | Southwestern Electric Power Co [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		0		0		0
Generation and Marketing Revenues [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		169,100,000		9,500,000		25,100,000
Generation and Marketing Revenues [Member] | AEP Texas Inc. [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		0		0		0
Generation and Marketing Revenues [Member] | Appalachian Power Co [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		0		0		0
Generation and Marketing Revenues [Member] | Indiana Michigan Power Co [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		0		0		0
Generation and Marketing Revenues [Member] | Ohio Power Co [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		0		0		0
Generation and Marketing Revenues [Member] | Public Service Co Of Oklahoma [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		0		0		0
Generation and Marketing Revenues [Member] | Southwestern Electric Power Co [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		0		0		0
Electric Generation, Transmission and Distribution Revenues [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		0		0		0
Electric Generation, Transmission and Distribution Revenues [Member] | AEP Texas Inc. [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		0		0		0
Electric Generation, Transmission and Distribution Revenues [Member] | Appalachian Power Co [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		(500,000)		400,000		100,000
Electric Generation, Transmission and Distribution Revenues [Member] | Indiana Michigan Power Co [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		(100,000)		100,000		500,000
Electric Generation, Transmission and Distribution Revenues [Member] | Ohio Power Co [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		0		0		0
Electric Generation, Transmission and Distribution Revenues [Member] | Public Service Co Of Oklahoma [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		0		0		0
Electric Generation, Transmission and Distribution Revenues [Member] | Southwestern Electric Power Co [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		0		100,000		100,000
Purchased Electricity for Resale [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		2,000,000.0		1,400,000		1,900,000
Purchased Electricity for Resale [Member] | AEP Texas Inc. [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		0		0		0
Purchased Electricity for Resale [Member] | Appalachian Power Co [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		1,800,000		1,200,000		1,600,000
Purchased Electricity for Resale [Member] | Indiana Michigan Power Co [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		0		100,000		100,000
Purchased Electricity for Resale [Member] | Ohio Power Co [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		0		0		0
Purchased Electricity for Resale [Member] | Public Service Co Of Oklahoma [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		0		0		0
Purchased Electricity for Resale [Member] | Southwestern Electric Power Co [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		0		0		0
Other Operation Expense [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		2,800,000		(2,000,000.0)		(800,000)
Other Operation Expense [Member] | AEP Texas Inc. [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		800,000		(600,000)		(200,000)
Other Operation Expense [Member] | Appalachian Power Co [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		300,000		(200,000)		(100,000)
Other Operation Expense [Member] | Indiana Michigan Power Co [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		300,000		(200,000)		(100,000)
Other Operation Expense [Member] | Ohio Power Co [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		500,000		(300,000)		(200,000)
Other Operation Expense [Member] | Public Service Co Of Oklahoma [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		300,000		(200,000)		(100,000)
Other Operation Expense [Member] | Southwestern Electric Power Co [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		400,000		(300,000)		(100,000)
Maintenance Expense [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		3,400,000		(2,900,000)		(800,000)
Maintenance Expense [Member] | AEP Texas Inc. [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		1,000,000.0		(800,000)		(200,000)
Maintenance Expense [Member] | Appalachian Power Co [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		500,000		(400,000)		(200,000)
Maintenance Expense [Member] | Indiana Michigan Power Co [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		300,000		(300,000)		(100,000)
Maintenance Expense [Member] | Ohio Power Co [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		600,000		(500,000)		(200,000)
Maintenance Expense [Member] | Public Service Co Of Oklahoma [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		400,000		(300,000)		(100,000)
Maintenance Expense [Member] | Southwestern Electric Power Co [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		500,000		(400,000)		(100,000)
Regulatory Assets [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	[15]	(9,100,000)		(4,800,000)		(3,700,000)
Regulatory Assets [Member] | AEP Texas Inc. [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	[15]	0		0		700,000
Regulatory Assets [Member] | Appalachian Power Co [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	[15]	(2,700,000)		0		300,000
Regulatory Assets [Member] | Indiana Michigan Power Co [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	[15]	(14,800,000)		(100,000)		300,000
Regulatory Assets [Member] | Ohio Power Co [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	[15]	10,000,000.0		(6,600,000)		(3,700,000)
Regulatory Assets [Member] | Public Service Co Of Oklahoma [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	[15]	(3,600,000)		0		1,200,000
Regulatory Assets [Member] | Southwestern Electric Power Co [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	[15]	3,600,000		1,400,000		(1,500,000)
Regulatory Liabilities [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	[15]	156,400,000		114,900,000		102,600,000
Regulatory Liabilities [Member] | AEP Texas Inc. [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	[15]	200,000		400,000		0
Regulatory Liabilities [Member] | Appalachian Power Co [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	[15]	55,900,000		20,300,000		2,400,000
Regulatory Liabilities [Member] | Indiana Michigan Power Co [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	[15]	(3,900,000)		12,400,000		24,500,000
Regulatory Liabilities [Member] | Ohio Power Co [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	[15]	0		12,400,000		10,100,000
Regulatory Liabilities [Member] | Public Service Co Of Oklahoma [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	[15]	48,900,000		39,100,000		34,600,000
Regulatory Liabilities [Member] | Southwestern Electric Power Co [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	[15]	$ 37,000,000.0		$ 20,200,000		$ 26,600,000

[1] Amounts include $(46) million and $(53) million as of December 31, 2021 and 2020, respectively, for the fair value hedge adjustment of hedged debt obligations for which hedge accounting has been discontinued

[2] Amounts included on the balance sheets within Long-term Debt Due within One Year and Long-term Debt, respectively.

[3] Gain (Loss) is included in Interest Expense on the statements of income.

[4] Amount excludes Risk Management Assets of $6 million classified as Assets Held for Sale on the balance sheets. See “Disposition of KPCo and KTCo” section of Note 7 for additional information.

[5] Amounts in “Other” column primarily represent counterparty netting of risk management and hedging contracts and associated cash collateral under the accounting guidance for “Derivatives and Hedging.”

[6] The December 31, 2021 maturities of the net fair value of risk management contracts prior to cash collateral, assets/(liabilities), were as follows: Level 1 matures $1 million in 2022 and $1 million in periods 2023-2025; Level 2 matures $42 million in 2022, $109 million in periods 2023-2025, $10 million in periods 2026-2027 and $3 million in periods 2028-2033; Level 3 matures $82 million in 2022, $10 million in periods 2023-2025, $9 million in periods 2026-2027 and $(17) million in periods 2028-2033. Risk management commodity contracts are substantially comprised of power contracts.

[7] The December 31, 2020 maturities of the net fair value of risk management contracts prior to cash collateral, assets/(liabilities), were as follows: Level 2 matures $3 million in periods 2022-2024, $11 million in periods 2025-2026 and $1 million in periods 2027-2033; Level 3 matures $47 million in 2021, $37 million in periods 2022-2024, $14 million in periods 2025-2026 and $(13) million in periods 2027-2033.  Risk management commodity contracts are substantially comprised of power contracts.

[8] Amount excludes Risk Management Liabilities of $0.1 million classified as Liabilities Held for Sale on the balance sheets. See “Disposition of KPCo and KTCo” section of Note 7 for additional information.

[9] Substantially comprised of power contracts for the Registrant Subsidiaries.

[10] Amount excludes Risk Management Assets of $6 million classified as Assets Held for Sale on the balance sheets. See “Disposition of KPCo and KTCo” section of Note 7 for additional information.

[11] Derivative instruments within these categories are disclosed as gross.  These instruments are subject to master netting agreements and are presented on the balance sheets on a net basis in accordance with the accounting guidance for “Derivatives and Hedging.”

[12] Amount excludes Risk Management Liabilities of $0.1 million classified as Liabilities Held for Sale on the balance sheets. See “Disposition of KPCo and KTCo” section of Note 7 for additional information.

[13] Amounts include counterparty netting of risk management and hedging contracts and associated cash collateral in accordance with the accounting guidance for “Derivatives and Hedging.”

[14] All derivative contracts subject to a master netting arrangement or similar agreement are offset in the statement of financial position.

[15] Represents realized and unrealized gains and losses subject to regulatory accounting treatment recorded as either current or noncurrent on the balance sheets.