Derivatives and Hedging (Details) gal in Millions, MWh in Millions, MMBTU in Millions		3 Months Ended			12 Months Ended
		Mar. 31, 2022 USD ($) MWh MMBTU gal		Mar. 31, 2021 USD ($)	Dec. 31, 2021 USD ($) MWh MMBTU gal
Cash Collateral Netting
Cash Collateral Received Netted Against Risk Management Assets		$ 655,000,000			$ 263,000,000
Cash Collateral Paid Netted Against Risk Management Liabilities		0			3,000,000
Fair Value of Derivative Instruments
Current Risk Management Assets		310,700,000			194,400,000
Long-term Risk Management Assets		260,800,000			267,000,000.0
Total Assets		571,500,000			461,400,000
Current Risk Management Liabilities		130,000,000.0			75,400,000
Long-term Risk Management Liabilities		300,400,000			230,300,000
Total Liabilities		430,400,000			305,700,000
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		215,300,000		$ 29,400,000
Carrying Amount of Hedged Asset (Liability)	[1],[2]	(906,000,000.0)			(952,300,000)
Cumulative Fair Value Hedging Adjustment in the Carrying Amount of the Hedged Asset (Liability)	[1],[2]	38,200,000			(8,500,000)
Gain (Loss) on Hedging Instruments
Gain (Loss) on Fair Value Hedging Instruments	[3]	(44,800,000)		(33,200,000)
Gain (Loss) on Fair Value Portion of Long Term Debt	[3]	44,800,000		33,200,000
Collateral Triggering Events [Abstract]
Fair Value Of Derivative Liabilities Subject To Cross Acceleration Provisions		82,000,000			40,000,000
Fair Value Of Derivative Liabilities Subject To Cross Default Provisions		167,000,000			76,000,000
Derivatives and Hedging (Textuals) [Abstract]
Hedged Liability, Discontinued Fair Value Hedge, Cumulative Increase (Decrease)		(44,000,000)			(46,000,000)
Credit Downgrade Trigger Exposure		27,000,000			9,000,000
Assets Held for Sale		2,972,600,000			2,919,700,000
Liabilities Held for Sale		1,873,700,000			1,880,900,000
Investment in Private Investee
Derivatives and Hedging (Textuals) [Abstract]
Equity Method Investments, Fair Value Disclosure		30,000,000
Unrealized Gain (Loss) on Investments		1,000,000		27,000,000
AEP Texas Inc. [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets		200,000			0
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		1,300,000		600,000
Appalachian Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets		7,000,000.0			42,000,000.0
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		100,000		4,100,000
AEP Transmission Co [Member]
Derivatives and Hedging (Textuals) [Abstract]
Assets Held for Sale		169,900,000			167,900,000
Liabilities Held for Sale		27,600,000			27,600,000
Indiana Michigan Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets		1,500,000			3,300,000
Current Risk Management Liabilities		400,000			5,000,000.0
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		200,000		(4,000,000.0)
Ohio Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Liabilities		1,500,000			6,700,000
Long-term Risk Management Liabilities		67,000,000.0			85,800,000
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		24,100,000		9,700,000
Public Service Co Of Oklahoma [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets		6,700,000			12,100,000
Current Risk Management Liabilities		100,000			3,700,000
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		16,500,000		11,300,000
Southwestern Electric Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets		15,800,000			9,800,000
Current Risk Management Liabilities		0			2,100,000
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		19,000,000.0		7,100,000
Risk Management Contracts [Member]
Fair Value of Derivative Instruments
Total Assets	[4],[5]	52,800,000	[6]		239,800,000	[7]
Total Liabilities	[5],[8]	345,400,000	[6]		254,700,000	[7]
Derivatives and Hedging (Textuals) [Abstract]
Assets Held for Sale		1,400,000			6,000,000
Liabilities Held for Sale					100,000
Risk Management Contracts [Member] | AEP Texas Inc. [Member]
Fair Value of Derivative Instruments
Total Assets	[5]	200,000			0
Risk Management Contracts [Member] | Appalachian Power Co [Member]
Fair Value of Derivative Instruments
Total Assets	[5],[9]	7,000,000.0			42,000,000.0
Total Liabilities	[5],[9]	200,000			800,000
Risk Management Contracts [Member] | Indiana Michigan Power Co [Member]
Fair Value of Derivative Instruments
Total Assets	[5],[9]	1,500,000			3,300,000
Total Liabilities	[5],[9]	400,000			5,000,000.0
Risk Management Contracts [Member] | Ohio Power Co [Member]
Fair Value of Derivative Instruments
Total Assets	[5],[9]	100,000			0
Total Liabilities	[9]	68,500,000			92,500,000
Risk Management Contracts [Member] | Public Service Co Of Oklahoma [Member]
Fair Value of Derivative Instruments
Total Assets	[5],[9]	6,700,000			12,100,000
Total Liabilities	[5],[9]	100,000			3,700,000
Risk Management Contracts [Member] | Southwestern Electric Power Co [Member]
Fair Value of Derivative Instruments
Total Assets	[5],[9]	15,800,000			10,900,000
Total Liabilities	[5],[9]	0			2,100,000
Commodity [Member]
Impact of Cash Flow Hedges on the Condensed Balance Sheet
AOCI Gain (Loss) Net of Tax		404,000,000.0			163,700,000
Portion Expected to be Reclassified to Net Income During the Next Twelve Months		$ 303,900,000			106,700,000
Derivatives and Hedging (Textuals) [Abstract]
Maximum Term for Exposure to Variability of Future Cash Flows		108 months
Cross Acceleration Provisions Maximum Third Party Obligation Amount		$ 50,000,000
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	[10],[11]	965,800,000			513,400,000
Long-term Risk Management Assets	[11]	497,000,000.0			370,500,000
Total Assets	[11]	1,462,800,000			883,900,000
Current Risk Management Liabilities	[11],[12]	754,600,000			395,700,000
Long-term Risk Management Liabilities	[11]	346,600,000			243,900,000
Total Liabilities	[11]	1,101,200,000			639,600,000
Total MTM Derivative Contract Net Assets (Liabilities)	[11]	361,600,000			244,300,000
Commodity [Member] | Risk Management Contracts [Member] | AEP Texas Inc. [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[11]	1,500,000			600,000
Long-term Risk Management Assets	[11]	0			0
Total Assets	[11]	1,500,000			600,000
Current Risk Management Liabilities	[11]	0			0
Long-term Risk Management Liabilities	[11]	0			0
Total Liabilities	[11]	0			0
Total MTM Derivative Contract Net Assets (Liabilities)	[11]	1,500,000			600,000
Commodity [Member] | Risk Management Contracts [Member] | Appalachian Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[11]	10,800,000			47,500,000
Long-term Risk Management Assets	[11]	500,000			200,000
Total Assets	[11]	11,300,000			47,700,000
Current Risk Management Liabilities	[11]	3,200,000			7,200,000
Long-term Risk Management Liabilities	[11]	500,000			200,000
Total Liabilities	[11]	3,700,000			7,400,000
Total MTM Derivative Contract Net Assets (Liabilities)	[11]	7,600,000			40,300,000
Commodity [Member] | Risk Management Contracts [Member] | Indiana Michigan Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[11]	4,600,000			11,100,000
Long-term Risk Management Assets	[11]	300,000			200,000
Total Assets	[11]	4,900,000			11,300,000
Current Risk Management Liabilities	[11]	2,900,000			14,800,000
Long-term Risk Management Liabilities	[11]	300,000			200,000
Total Liabilities	[11]	3,200,000			15,000,000.0
Total MTM Derivative Contract Net Assets (Liabilities)	[11]	1,700,000			(3,700,000)
Commodity [Member] | Risk Management Contracts [Member] | Ohio Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[11]	1,100,000			500,000
Long-term Risk Management Assets	[11]	0			0
Total Assets	[11]	1,100,000			500,000
Current Risk Management Liabilities	[11]	1,500,000			6,700,000
Long-term Risk Management Liabilities	[11]	67,000,000.0			85,800,000
Total Liabilities	[11]	68,500,000			92,500,000
Total MTM Derivative Contract Net Assets (Liabilities)	[11]	(67,400,000)			(92,000,000.0)
Commodity [Member] | Risk Management Contracts [Member] | Public Service Co Of Oklahoma [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[11]	7,900,000			12,400,000
Long-term Risk Management Assets	[11]	0			0
Total Assets	[11]	7,900,000			12,400,000
Current Risk Management Liabilities	[11]	800,000			3,700,000
Long-term Risk Management Liabilities	[11]	0			0
Total Liabilities	[11]	800,000			3,700,000
Total MTM Derivative Contract Net Assets (Liabilities)	[11]	7,100,000			8,700,000
Commodity [Member] | Risk Management Contracts [Member] | Southwestern Electric Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[11]	16,700,000			10,100,000
Long-term Risk Management Assets	[11]	0			1,100,000
Total Assets	[11]	16,700,000			11,200,000
Current Risk Management Liabilities	[11]	200,000			2,100,000
Long-term Risk Management Liabilities	[11]	0			0
Total Liabilities	[11]	200,000			2,100,000
Total MTM Derivative Contract Net Assets (Liabilities)	[11]	16,500,000			9,100,000
Commodity [Member] | Hedging Contracts [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[11]	420,500,000			176,000,000.0
Long-term Risk Management Assets	[11]	140,400,000			89,100,000
Total Assets	[11]	560,900,000			265,100,000
Current Risk Management Liabilities	[11]	35,800,000			40,900,000
Long-term Risk Management Liabilities	[11]	13,500,000			16,700,000
Total Liabilities	[11]	49,300,000			57,600,000
Total MTM Derivative Contract Net Assets (Liabilities)	[11]	511,600,000			207,500,000
Interest Rate [Member]
Commodity:
Derivative, Notional Amount		1,150,000,000			950,000,000.0
Impact of Cash Flow Hedges on the Condensed Balance Sheet
AOCI Gain (Loss) Net of Tax		(13,600,000)			(21,300,000)
Portion Expected to be Reclassified to Net Income During the Next Twelve Months		$ (2,900,000)			(3,300,000)
Derivatives and Hedging (Textuals) [Abstract]
Maximum Term for Exposure to Variability of Future Cash Flows		105 months
Deferred (Gain) Loss on Discontinuation of Fair Value Hedge		$ 57,000,000
Notional Amount of a Discontinued Hedge		500,000,000
Interest Rate [Member] | AEP Texas Inc. [Member]
Commodity:
Derivative, Notional Amount		0			0
Impact of Cash Flow Hedges on the Condensed Balance Sheet
AOCI Gain (Loss) Net of Tax		(1,000,000.0)			(1,300,000)
Portion Expected to be Reclassified to Net Income During the Next Twelve Months		(1,000,000.0)			(1,100,000)
Interest Rate [Member] | Appalachian Power Co [Member]
Commodity:
Derivative, Notional Amount		0			0
Impact of Cash Flow Hedges on the Condensed Balance Sheet
AOCI Gain (Loss) Net of Tax		7,300,000			7,500,000
Portion Expected to be Reclassified to Net Income During the Next Twelve Months		800,000			800,000
Interest Rate [Member] | Indiana Michigan Power Co [Member]
Commodity:
Derivative, Notional Amount		0			0
Impact of Cash Flow Hedges on the Condensed Balance Sheet
AOCI Gain (Loss) Net of Tax		(6,300,000)			(6,700,000)
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
Interest Rate [Member] | Southwestern Electric Power Co [Member]
Commodity:
Derivative, Notional Amount		0			0
Impact of Cash Flow Hedges on the Condensed Balance Sheet
AOCI Gain (Loss) Net of Tax		1,300,000			1,200,000
Portion Expected to be Reclassified to Net Income During the Next Twelve Months		200,000			100,000
Interest Rate [Member] | Hedging Contracts [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[11]	0			1,200,000
Long-term Risk Management Assets	[11]	3,900,000			0
Total Assets	[11]	3,900,000			1,200,000
Current Risk Management Liabilities	[11]	2,300,000			0
Long-term Risk Management Liabilities	[11]	79,500,000			38,100,000
Total Liabilities	[11]	81,800,000			38,100,000
Total MTM Derivative Contract Net Assets (Liabilities)	[11]	(77,900,000)			(36,900,000)
Gross Amounts of Risk Management Assets/Liabilities Recognized [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[10]	1,386,300,000			690,600,000
Long-term Risk Management Assets		641,300,000			459,600,000
Total Assets		2,027,600,000			1,150,200,000
Current Risk Management Liabilities	[12]	792,700,000			436,600,000
Long-term Risk Management Liabilities		439,600,000			298,700,000
Total Liabilities		1,232,300,000			735,300,000
Total MTM Derivative Contract Net Assets (Liabilities)		795,300,000			414,900,000
Gross Amounts Offset in the Statement of Financial Position [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[10],[13]	(1,075,600,000)			(496,200,000)
Long-term Risk Management Assets	[13]	(380,500,000)			(192,600,000)
Total Assets	[13]	(1,456,100,000)			(688,800,000)
Current Risk Management Liabilities	[12],[13]	(662,700,000)			(361,200,000)
Long-term Risk Management Liabilities	[13]	(139,200,000)			(68,400,000)
Total Liabilities	[13]	(801,900,000)			(429,600,000)
Total MTM Derivative Contract Net Assets (Liabilities)	[13]	(654,200,000)			(259,200,000)
Gross Amounts Offset in the Statement of Financial Position [Member] | AEP Texas Inc. [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[13]	(1,300,000)			(600,000)
Long-term Risk Management Assets	[13]	0			0
Total Assets	[13]	(1,300,000)			(600,000)
Current Risk Management Liabilities	[13]	0			0
Long-term Risk Management Liabilities	[13]	0			0
Total Liabilities	[13]	0			0
Total MTM Derivative Contract Net Assets (Liabilities)	[13]	(1,300,000)			(600,000)
Gross Amounts Offset in the Statement of Financial Position [Member] | Appalachian Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[13]	(3,800,000)			(5,500,000)
Long-term Risk Management Assets	[13]	(500,000)			(200,000)
Total Assets	[13]	(4,300,000)			(5,700,000)
Current Risk Management Liabilities	[13]	(3,000,000.0)			(6,400,000)
Long-term Risk Management Liabilities	[13]	(500,000)			(200,000)
Total Liabilities	[13]	(3,500,000)			(6,600,000)
Total MTM Derivative Contract Net Assets (Liabilities)	[13]	(800,000)			900,000
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]	(3,100,000)			(7,800,000)
Long-term Risk Management Assets	[13]	(300,000)			(200,000)
Total Assets	[13]	(3,400,000)			(8,000,000.0)
Current Risk Management Liabilities	[13]	(2,500,000)			(9,800,000)
Long-term Risk Management Liabilities	[13]	(300,000)			(200,000)
Total Liabilities	[13]	(2,800,000)			(10,000,000.0)
Total MTM Derivative Contract Net Assets (Liabilities)	[13]	(600,000)			2,000,000.0
Gross Amounts Offset in the Statement of Financial Position [Member] | Ohio Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[13]	(1,000,000.0)			(500,000)
Long-term Risk Management Assets	[13]	0			0
Total Assets	[13]	(1,000,000.0)			(500,000)
Current Risk Management Liabilities	[13]	0			0
Long-term Risk Management Liabilities	[13]	0			0
Total Liabilities	[13]	0			0
Total MTM Derivative Contract Net Assets (Liabilities)	[13]	(1,000,000.0)			(500,000)
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]	(1,200,000)			(300,000)
Long-term Risk Management Assets	[13]	0			0
Total Assets	[13]	(1,200,000)			(300,000)
Current Risk Management Liabilities	[13]	(700,000)			0
Long-term Risk Management Liabilities	[13]	0			0
Total Liabilities	[13]	(700,000)			0
Total MTM Derivative Contract Net Assets (Liabilities)	[13]	(500,000)			(300,000)
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]	(900,000)			(300,000)
Long-term Risk Management Assets	[13]	0			0
Total Assets	[13]	(900,000)			(300,000)
Current Risk Management Liabilities	[13]	(200,000)			0
Long-term Risk Management Liabilities	[13]	0			0
Total Liabilities	[13]	(200,000)			0
Total MTM Derivative Contract Net Assets (Liabilities)	[13]	(700,000)			(300,000)
Net Amounts of Assets/Liabilities Presented in the Statement of Financial Position [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[10],[14]	310,700,000			194,400,000
Long-term Risk Management Assets	[14]	260,800,000			267,000,000.0
Total Assets	[14]	571,500,000			461,400,000
Current Risk Management Liabilities	[12],[14]	130,000,000.0			75,400,000
Long-term Risk Management Liabilities	[14]	300,400,000			230,300,000
Total Liabilities	[14]	430,400,000			305,700,000
Total MTM Derivative Contract Net Assets (Liabilities)	[14]	141,100,000			155,700,000
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]	200,000			0
Long-term Risk Management Assets	[14]	0			0
Total Assets	[14]	200,000			0
Current Risk Management Liabilities	[14]	0			0
Long-term Risk Management Liabilities	[14]	0			0
Total Liabilities	[14]	0			0
Total MTM Derivative Contract Net Assets (Liabilities)	[14]	200,000			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]	7,000,000.0			42,000,000.0
Long-term Risk Management Assets	[14]	0			0
Total Assets	[14]	7,000,000.0			42,000,000.0
Current Risk Management Liabilities	[14]	200,000			800,000
Long-term Risk Management Liabilities	[14]	0			0
Total Liabilities	[14]	200,000			800,000
Total MTM Derivative Contract Net Assets (Liabilities)	[14]	6,800,000			41,200,000
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]	1,500,000			3,300,000
Long-term Risk Management Assets	[14]	0			0
Total Assets	[14]	1,500,000			3,300,000
Current Risk Management Liabilities	[14]	400,000			5,000,000.0
Long-term Risk Management Liabilities	[14]	0			0
Total Liabilities	[14]	400,000			5,000,000.0
Total MTM Derivative Contract Net Assets (Liabilities)	[14]	1,100,000			(1,700,000)
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]	100,000			0
Long-term Risk Management Assets	[14]	0			0
Total Assets	[14]	100,000			0
Current Risk Management Liabilities	[14]	1,500,000			6,700,000
Long-term Risk Management Liabilities	[14]	67,000,000.0			85,800,000
Total Liabilities	[14]	68,500,000			92,500,000
Total MTM Derivative Contract Net Assets (Liabilities)	[14]	(68,400,000)			(92,500,000)
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]	6,700,000			12,100,000
Long-term Risk Management Assets	[14]	0			0
Total Assets	[14]	6,700,000			12,100,000
Current Risk Management Liabilities	[14]	100,000			3,700,000
Long-term Risk Management Liabilities	[14]	0			0
Total Liabilities	[14]	100,000			3,700,000
Total MTM Derivative Contract Net Assets (Liabilities)	[14]	6,600,000			8,400,000
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]	15,800,000			9,800,000
Long-term Risk Management Assets	[14]	0			1,100,000
Total Assets	[14]	15,800,000			10,900,000
Current Risk Management Liabilities	[14]	0			2,100,000
Long-term Risk Management Liabilities	[14]	0			0
Total Liabilities	[14]	0			2,100,000
Total MTM Derivative Contract Net Assets (Liabilities)	[14]	$ 15,800,000			$ 8,800,000
Power [Member]
Commodity:
Derivative, Energy Notional Amount | MWh		241.4			287.9
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		13.2			33.1
Power [Member] | Indiana Michigan Power Co [Member]
Commodity:
Derivative, Energy Notional Amount | MWh		5.3			13.6
Power [Member] | Ohio Power Co [Member]
Commodity:
Derivative, Energy Notional Amount | MWh		2.7			2.7
Power [Member] | Public Service Co Of Oklahoma [Member]
Commodity:
Derivative, Energy Notional Amount | MWh		4.5			11.9
Power [Member] | Southwestern Electric Power Co [Member]
Commodity:
Derivative, Energy Notional Amount | MWh		2.3			3.4
Natural Gas [Member]
Commodity:
Derivative, Energy Notional Amount | MMBTU		45.6			34.1
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		0.0			1.3
Natural Gas [Member] | Southwestern Electric Power Co [Member]
Commodity:
Derivative, Energy Notional Amount | MMBTU		3.7			5.1
Heating Oil and Gasoline [Member]
Commodity:
Derivative, Volume Notional Amount | gal		5.4			7.4
Heating Oil and Gasoline [Member] | AEP Texas Inc. [Member]
Commodity:
Derivative, Volume Notional Amount | gal		1.4			1.9
Heating Oil and Gasoline [Member] | Appalachian Power Co [Member]
Commodity:
Derivative, Volume Notional Amount | gal		0.8			1.1
Heating Oil and Gasoline [Member] | Indiana Michigan Power Co [Member]
Commodity:
Derivative, Volume Notional Amount | gal		0.5			0.7
Heating Oil and Gasoline [Member] | Ohio Power Co [Member]
Commodity:
Derivative, Volume Notional Amount | gal		1.1			1.5
Heating Oil and Gasoline [Member] | Public Service Co Of Oklahoma [Member]
Commodity:
Derivative, Volume Notional Amount | gal		0.6			0.8
Heating Oil and Gasoline [Member] | Southwestern Electric Power Co [Member]
Commodity:
Derivative, Volume Notional Amount | gal		0.8			1.0
Interest Rate Contract [Member]
Commodity:
Derivative, Notional Amount		$ 108,600,000			$ 116,500,000
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
Fair Value of Derivative Instruments
Total Assets		15,000,000			15,000,000
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		1,000,000		(10,000,000)
Held For Sale
Derivatives and Hedging (Textuals) [Abstract]
Assets Held for Sale		1,400,000			6,000,000
Liabilities Held for Sale		0			$ 100,000
Vertically Integrated Utilities Revenues [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts				200,000
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
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
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
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
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
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
Generation and Marketing Revenues [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		152,300,000		(400,000)
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
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
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
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
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
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
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
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
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		100,000		200,000
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)		0
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
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
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		0
Purchased Electricity for Resale [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		1,500,000		400,000
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
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		1,400,000		400,000
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		0
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
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
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
Other Operation Expense [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		600,000		300,000
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		200,000		100,000
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		0		0
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		100,000		0
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		100,000		100,000
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		100,000		0
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		100,000		0
Maintenance Expense [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		800,000		500,000
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		200,000		100,000
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		100,000		100,000
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		100,000		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		100,000		100,000
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		100,000		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		100,000		100,000
Regulatory Assets [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	[15]	23,600,000		6,400,000
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
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]	(100,000)		0
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]	(1,600,000)		(900,000)
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]	23,900,000		6,600,000
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
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]	(2,100,000)		800,000
Regulatory Liabilities [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	[15]	36,500,000		22,000,000.0
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]	900,000		400,000
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]	(1,400,000)		3,400,000
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]	1,700,000		(3,200,000)
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		2,900,000
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]	12,700,000		11,200,000
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]	$ 20,900,000		$ 6,200,000

[1] Amounts include $(44) million and $(46) million as of March 31, 2022 and December 31, 2021, 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 $1.4 million and $6 million as of March 31, 2022 and December 31, 2021, respectively, classified as Assets Held for Sale on the balance sheets. See “Disposition of KPCo and KTCo” section of Note 6 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 March 31, 2022 maturities of the net fair value of risk management contracts prior to cash collateral, assets/(liabilities), were as follows: Level 1 matures $14 million in 2022 and $4 million in periods 2023-2025; Level 2 matures $96 million in 2022, $188 million in periods 2023-2025, $10 million in periods 2026-2027 and $4 million in periods 2028-2033; Level 3 matures $37 million in 2022, $8 million in periods 2023-2025, $13 million in periods 2026-2027 and $(11) million in periods 2028-2033.  Risk management commodity contracts are substantially comprised of power contracts.

[7] 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.

[8] Amount excludes Risk Management Liabilities of $0 and $0.1 million as of March 31, 2022 and December 31, 2021, respectively, classified as Liabilities Held for Sale on the balance sheets. See “Disposition of KPCo and KTCo” section of Note 6 for additional information.

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

[10] Amount excludes Risk Management Assets of $1.4 million and $6 million as of March 31, 2022 and December 31, 2021, respectively, classified as Assets Held for Sale on the balance sheets. See “Disposition of KPCo and KTCo” section of Note 6 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 and $0.1 million as of March 31, 2022 and December 31, 2021, respectively, classified as Liabilities Held for Sale on the balance sheets. See “Disposition of KPCo and KTCo” section of Note 6 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.