Derivatives and Hedging (Details) gal in Millions, MWh in Millions, MMBTU in Millions		3 Months Ended			9 Months Ended			12 Months Ended
		Sep. 30, 2023 USD ($) MWh MMBTU gal		Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($) MWh MMBTU gal		Sep. 30, 2022 USD ($)	Dec. 31, 2022 USD ($) MMBTU MWh gal
Cash Collateral Netting
Cash Collateral Received Netted Against Risk Management Assets		$ 93,000,000			$ 93,000,000			$ 481,000,000
Fair Value of Derivative Instruments
Current Risk Management Assets		262,700,000			262,700,000			348,800,000
Long-term Risk Management Assets		290,200,000			290,200,000			284,100,000
Total Assets		552,900,000			552,900,000			632,900,000
Current Risk Management Liabilities		151,500,000			151,500,000			145,200,000
Long-term Risk Management Liabilities		278,400,000			278,400,000			345,200,000
Total Liabilities		429,900,000			429,900,000			490,400,000
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		33,100,000		$ 230,600,000	(179,400,000)		$ 703,800,000
Carrying Amount of Hedged Asset (Liability)	[1],[2]	(840,100,000)			(840,100,000)			(855,500,000)
Cumulative Fair Value Hedging Adjustment in the Carrying Amount of the Hedged Asset (Liability)	[1],[2]	106,100,000			106,100,000			89,700,000
Gain (Loss) on Hedging Instruments
Gain (Loss) on Fair Value Hedging Instruments	[3]	(13,400,000)		(36,000,000.0)	(10,700,000)		(98,400,000)
Gain (Loss) on Fair Value Portion of Long Term Debt	[3]	13,400,000		36,000,000.0	10,700,000		98,400,000
Collateral Triggering Events [Abstract]
Fair Value Of Derivative Liabilities Subject To Cross Acceleration Provisions		138,000,000			138,000,000			127,000,000
Fair Value Of Derivative Liabilities Subject To Cross Default Provisions		165,000,000			165,000,000			217,000,000
Derivatives and Hedging (Textuals) [Abstract]
Hedged Liability, Discontinued Fair Value Hedge, Cumulative Increase (Decrease)		(32,000,000)			(32,000,000)			(38,000,000)
Credit Downgrade Trigger Exposure		0			0			2,000,000
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		2,000,000.0
Appalachian Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets		46,400,000			46,400,000			69,100,000
Current Risk Management Liabilities		1,800,000			1,800,000			3,600,000
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		13,300,000		61,200,000	5,200,000		84,300,000
Indiana Michigan Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets		15,800,000			15,800,000			15,200,000
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		(6,300,000)		6,200,000	8,200,000		8,600,000
Ohio Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Liabilities		5,700,000			5,700,000			1,800,000
Long-term Risk Management Liabilities		45,900,000			45,900,000			37,900,000
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		400,000		5,600,000	(24,700,000)		53,000,000.0
Public Service Co Of Oklahoma [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets		28,200,000			28,200,000			25,300,000
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		9,300,000		20,100,000	66,200,000		76,200,000
Southwestern Electric Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets		17,100,000			17,100,000			16,400,000
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		11,500,000		7,600,000	54,600,000		64,100,000
Risk Management Contracts [Member]
Fair Value of Derivative Instruments
Total Assets	[4]	424,500,000	[5]		424,500,000	[5]		315,400,000	[6]
Total Liabilities	[4]	291,200,000	[5]		291,200,000	[5]		339,800,000	[6]
Risk Management Contracts [Member] | AEP Texas Inc. [Member]
Fair Value of Derivative Instruments
Total Assets	[7]	400,000			400,000
Risk Management Contracts [Member] | Appalachian Power Co [Member]
Fair Value of Derivative Instruments
Total Assets	[4],[7]	46,600,000			46,600,000			69,100,000
Total Liabilities	[4],[7]	2,700,000			2,700,000			3,500,000
Risk Management Contracts [Member] | Indiana Michigan Power Co [Member]
Fair Value of Derivative Instruments
Total Assets	[4],[7]	21,200,000			21,200,000			15,400,000
Total Liabilities	[4],[7]	1,100,000			1,100,000			0
Risk Management Contracts [Member] | Ohio Power Co [Member]
Fair Value of Derivative Instruments
Total Assets	[7]	300,000			300,000
Total Liabilities	[7]	51,600,000			51,600,000			39,700,000
Risk Management Contracts [Member] | Public Service Co Of Oklahoma [Member]
Fair Value of Derivative Instruments
Total Assets	[4],[7]	28,200,000			28,200,000			25,300,000
Total Liabilities	[4],[7]	7,200,000			7,200,000			1,600,000
Risk Management Contracts [Member] | Southwestern Electric Power Co [Member]
Fair Value of Derivative Instruments
Total Assets	[4],[7]	17,100,000			17,100,000			16,400,000
Total Liabilities	[4],[7]	3,500,000			3,500,000			1,400,000
Commodity [Member]
Impact of Cash Flow Hedges on the Condensed Balance Sheet
AOCI Gain (Loss) Net of Tax		100,600,000			100,600,000			223,500,000
Portion Expected to be Reclassified to Net Income During the Next Twelve Months					$ 36,100,000			119,900,000
Derivatives and Hedging (Textuals) [Abstract]
Maximum Term for Exposure to Variability of Future Cash Flows					90 months
Cross Acceleration Provisions Maximum Third Party Obligation Amount		50,000,000			$ 50,000,000
Cross Default Provisions Maximum Third Party Obligation Amount		50,000,000			50,000,000
Commodity [Member] | Risk Management Contracts [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[8]	595,700,000			595,700,000			965,400,000
Long-term Risk Management Assets	[8]	465,300,000			465,300,000			565,600,000
Total Assets	[8]	1,061,000,000			1,061,000,000			1,531,000,000
Current Risk Management Liabilities	[8]	460,300,000			460,300,000			663,800,000
Long-term Risk Management Liabilities	[8]	374,800,000			374,800,000			412,000,000.0
Total Liabilities	[8]	835,100,000			835,100,000			1,075,800,000
Total MTM Derivative Contract Net Assets (Liabilities)	[8]	225,900,000			225,900,000			455,200,000
Commodity [Member] | Risk Management Contracts [Member] | AEP Texas Inc. [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[8]	400,000			400,000			0
Long-term Risk Management Assets	[8]	0			0			0
Total Assets	[8]	400,000			400,000			0
Current Risk Management Liabilities	[8]	0			0			0
Long-term Risk Management Liabilities	[8]	0			0			0
Total Liabilities	[8]	0			0			0
Total MTM Derivative Contract Net Assets (Liabilities)	[8]	400,000			400,000			0
Commodity [Member] | Risk Management Contracts [Member] | Appalachian Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[8]	48,800,000			48,800,000			69,300,000
Long-term Risk Management Assets	[8]	800,000			800,000			700,000
Total Assets	[8]	49,600,000			49,600,000			70,000,000.0
Current Risk Management Liabilities	[8]	4,200,000			4,200,000			4,100,000
Long-term Risk Management Liabilities	[8]	1,500,000			1,500,000			700,000
Total Liabilities	[8]	5,700,000			5,700,000			4,800,000
Total MTM Derivative Contract Net Assets (Liabilities)	[8]	43,900,000			43,900,000			65,200,000
Commodity [Member] | Risk Management Contracts [Member] | Indiana Michigan Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[8]	20,200,000			20,200,000			16,000,000.0
Long-term Risk Management Assets	[8]	6,600,000			6,600,000			500,000
Total Assets	[8]	26,800,000			26,800,000			16,500,000
Current Risk Management Liabilities	[8]	5,300,000			5,300,000			900,000
Long-term Risk Management Liabilities	[8]	1,000,000.0			1,000,000.0			300,000
Total Liabilities	[8]	6,300,000			6,300,000			1,200,000
Total MTM Derivative Contract Net Assets (Liabilities)	[8]	20,500,000			20,500,000			15,300,000
Commodity [Member] | Risk Management Contracts [Member] | Ohio Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[8]	300,000			300,000			0
Long-term Risk Management Assets	[8]	0			0			0
Total Assets	[8]	300,000			300,000			0
Current Risk Management Liabilities	[8]	5,700,000			5,700,000			2,100,000
Long-term Risk Management Liabilities	[8]	45,900,000			45,900,000			37,900,000
Total Liabilities	[8]	51,600,000			51,600,000			40,000,000.0
Total MTM Derivative Contract Net Assets (Liabilities)	[8]	(51,300,000)			(51,300,000)			(40,000,000.0)
Commodity [Member] | Risk Management Contracts [Member] | Public Service Co Of Oklahoma [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[8]	28,300,000			28,300,000			24,100,000
Long-term Risk Management Assets	[8]	300,000			300,000			0
Total Assets	[8]	28,600,000			28,600,000			24,100,000
Current Risk Management Liabilities	[8]	7,200,000			7,200,000			2,100,000
Long-term Risk Management Liabilities	[8]	400,000			400,000			0
Total Liabilities	[8]	7,600,000			7,600,000			2,100,000
Total MTM Derivative Contract Net Assets (Liabilities)	[8]	21,000,000.0			21,000,000.0			22,000,000.0
Commodity [Member] | Risk Management Contracts [Member] | Southwestern Electric Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[8]	17,600,000			17,600,000			16,800,000
Long-term Risk Management Assets	[8]	0			0			0
Total Assets	[8]	17,600,000			17,600,000			16,800,000
Current Risk Management Liabilities	[8]	3,600,000			3,600,000			2,000,000.0
Long-term Risk Management Liabilities	[8]	400,000			400,000			0
Total Liabilities	[8]	4,000,000.0			4,000,000.0			2,000,000.0
Total MTM Derivative Contract Net Assets (Liabilities)	[8]	13,600,000			13,600,000			14,800,000
Commodity [Member] | Hedging Contracts [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[8]	55,600,000			55,600,000			212,200,000
Long-term Risk Management Assets	[8]	83,300,000			83,300,000			148,900,000
Total Assets	[8]	138,900,000			138,900,000			361,100,000
Current Risk Management Liabilities	[8]	9,900,000			9,900,000			60,400,000
Long-term Risk Management Liabilities	[8]	1,200,000			1,200,000			17,400,000
Total Liabilities	[8]	11,100,000			11,100,000			77,800,000
Total MTM Derivative Contract Net Assets (Liabilities)	[8]	127,800,000			127,800,000			283,300,000
Interest Rate [Member]
Commodity:
Derivative, Notional Amount		950,000,000.0			950,000,000.0			1,650,000,000
Impact of Cash Flow Hedges on the Condensed Balance Sheet
AOCI Gain (Loss) Net of Tax		4,700,000			4,700,000			300,000
Portion Expected to be Reclassified to Net Income During the Next Twelve Months					4,300,000			300,000
Interest Rate [Member] | AEP Texas Inc. [Member]
Commodity:
Derivative, Notional Amount		0			0			0
Impact of Cash Flow Hedges on the Condensed Balance Sheet
AOCI Gain (Loss) Net of Tax		2,800,000			2,800,000			(300,000)
Portion Expected to be Reclassified to Net Income During the Next Twelve Months					300,000			(200,000)
Interest Rate [Member] | Appalachian Power Co [Member]
Commodity:
Derivative, Notional Amount		0			0			0
Impact of Cash Flow Hedges on the Condensed Balance Sheet
AOCI Gain (Loss) Net of Tax		6,100,000			6,100,000			6,700,000
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			0
Impact of Cash Flow Hedges on the Condensed Balance Sheet
AOCI Gain (Loss) Net of Tax		(5,600,000)			(5,600,000)			(5,100,000)
Portion Expected to be Reclassified to Net Income During the Next Twelve Months					(400,000)			(600,000)
Interest Rate [Member] | Ohio Power Co [Member]
Commodity:
Derivative, Notional Amount		0			0			0
Interest Rate [Member] | Public Service Co Of Oklahoma [Member]
Commodity:
Derivative, Notional Amount		0			0			200,000,000.0
Impact of Cash Flow Hedges on the Condensed Balance Sheet
AOCI Gain (Loss) Net of Tax		(200,000)			(200,000)			1,300,000
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			0
Impact of Cash Flow Hedges on the Condensed Balance Sheet
AOCI Gain (Loss) Net of Tax		1,400,000			1,400,000			1,100,000
Portion Expected to be Reclassified to Net Income During the Next Twelve Months					300,000			200,000
Interest Rate [Member] | Hedging Contracts [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[8]	0			0			1,800,000
Long-term Risk Management Assets	[8]	0			0			14,300,000
Total Assets	[8]	0			0			16,100,000
Current Risk Management Liabilities	[8]	43,200,000			43,200,000			41,400,000
Long-term Risk Management Liabilities	[8]	94,900,000			94,900,000			91,100,000
Total Liabilities	[8]	138,100,000			138,100,000			132,500,000
Total MTM Derivative Contract Net Assets (Liabilities)	[8]	(138,100,000)			(138,100,000)			(116,400,000)
Interest Rate [Member] | Hedging Contracts [Member] | Public Service Co Of Oklahoma [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[8]							1,600,000
Long-term Risk Management Assets	[8]							0
Total Assets	[8]							1,600,000
Current Risk Management Liabilities	[8]							0
Long-term Risk Management Liabilities	[8]							0
Total Liabilities	[8]							0
Total MTM Derivative Contract Net Assets (Liabilities)	[8]							1,600,000
Gross Amounts of Risk Management Assets/Liabilities Recognized [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets		651,300,000			651,300,000			1,179,400,000
Long-term Risk Management Assets		548,600,000			548,600,000			728,800,000
Total Assets		1,199,900,000			1,199,900,000			1,908,200,000
Current Risk Management Liabilities		513,400,000			513,400,000			765,600,000
Long-term Risk Management Liabilities		470,900,000			470,900,000			520,500,000
Total Liabilities		984,300,000			984,300,000			1,286,100,000
Total MTM Derivative Contract Net Assets (Liabilities)		215,600,000			215,600,000			622,100,000
Gross Amounts of Risk Management Assets/Liabilities Recognized [Member] | Public Service Co Of Oklahoma [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets								25,700,000
Long-term Risk Management Assets								0
Total Assets								25,700,000
Current Risk Management Liabilities								2,100,000
Long-term Risk Management Liabilities								0
Total Liabilities								2,100,000
Total MTM Derivative Contract Net Assets (Liabilities)								23,600,000
Gross Amounts Offset in the Statement of Financial Position [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[9]	(388,600,000)			(388,600,000)			(830,600,000)
Long-term Risk Management Assets	[9]	(258,400,000)			(258,400,000)			(444,700,000)
Total Assets	[9]	(647,000,000.0)			(647,000,000.0)			(1,275,300,000)
Current Risk Management Liabilities	[9]	(361,900,000)			(361,900,000)			(620,400,000)
Long-term Risk Management Liabilities	[9]	(192,500,000)			(192,500,000)			(175,300,000)
Total Liabilities	[9]	(554,400,000)			(554,400,000)			(795,700,000)
Total MTM Derivative Contract Net Assets (Liabilities)	[9]	(92,600,000)			(92,600,000)			(479,600,000)
Gross Amounts Offset in the Statement of Financial Position [Member] | AEP Texas Inc. [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[9]	0			0			0
Long-term Risk Management Assets	[9]	0			0			0
Total Assets	[9]	0			0			0
Current Risk Management Liabilities	[9]	0			0			0
Long-term Risk Management Liabilities	[9]	0			0			0
Total Liabilities	[9]	0			0			0
Total MTM Derivative Contract Net Assets (Liabilities)	[9]	0			0			0
Gross Amounts Offset in the Statement of Financial Position [Member] | Appalachian Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[9]	(2,400,000)			(2,400,000)			(200,000)
Long-term Risk Management Assets	[9]	(600,000)			(600,000)			(700,000)
Total Assets	[9]	(3,000,000.0)			(3,000,000.0)			(900,000)
Current Risk Management Liabilities	[9]	(2,400,000)			(2,400,000)			(500,000)
Long-term Risk Management Liabilities	[9]	(600,000)			(600,000)			(600,000)
Total Liabilities	[9]	(3,000,000.0)			(3,000,000.0)			(1,100,000)
Total MTM Derivative Contract Net Assets (Liabilities)	[9]	0			0			200,000
Gross Amounts Offset in the Statement of Financial Position [Member] | Indiana Michigan Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[9]	(4,400,000)			(4,400,000)			(800,000)
Long-term Risk Management Assets	[9]	(1,200,000)			(1,200,000)			(300,000)
Total Assets	[9]	(5,600,000)			(5,600,000)			(1,100,000)
Current Risk Management Liabilities	[9]	(4,200,000)			(4,200,000)			(900,000)
Long-term Risk Management Liabilities	[9]	(1,000,000.0)			(1,000,000.0)			(300,000)
Total Liabilities	[9]	(5,200,000)			(5,200,000)			(1,200,000)
Total MTM Derivative Contract Net Assets (Liabilities)	[9]	(400,000)			(400,000)			100,000
Gross Amounts Offset in the Statement of Financial Position [Member] | Ohio Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[9]	0			0			0
Long-term Risk Management Assets	[9]	0			0			0
Total Assets	[9]	0			0			0
Current Risk Management Liabilities	[9]	0			0			(300,000)
Long-term Risk Management Liabilities	[9]	0			0			0
Total Liabilities	[9]	0			0			(300,000)
Total MTM Derivative Contract Net Assets (Liabilities)	[9]	0			0			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	[9]	(100,000)			(100,000)			(400,000)
Long-term Risk Management Assets	[9]	(300,000)			(300,000)			0
Total Assets	[9]	(400,000)			(400,000)			(400,000)
Current Risk Management Liabilities	[9]	(100,000)			(100,000)			(500,000)
Long-term Risk Management Liabilities	[9]	(300,000)			(300,000)			0
Total Liabilities	[9]	(400,000)			(400,000)			(500,000)
Total MTM Derivative Contract Net Assets (Liabilities)	[9]	0			0			100,000
Gross Amounts Offset in the Statement of Financial Position [Member] | Southwestern Electric Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[9]	(500,000)			(500,000)			(400,000)
Long-term Risk Management Assets	[9]	0			0			0
Total Assets	[9]	(500,000)			(500,000)			(400,000)
Current Risk Management Liabilities	[9]	(500,000)			(500,000)			(600,000)
Long-term Risk Management Liabilities	[9]	0			0			0
Total Liabilities	[9]	(500,000)			(500,000)			(600,000)
Total MTM Derivative Contract Net Assets (Liabilities)	[9]	0			0			200,000
Net Amounts of Assets/Liabilities Presented in the Statement of Financial Position [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[10]	262,700,000			262,700,000			348,800,000
Long-term Risk Management Assets	[10]	290,200,000			290,200,000			284,100,000
Total Assets	[10]	552,900,000			552,900,000			632,900,000
Current Risk Management Liabilities	[10]	151,500,000			151,500,000			145,200,000
Long-term Risk Management Liabilities	[10]	278,400,000			278,400,000			345,200,000
Total Liabilities	[10]	429,900,000			429,900,000			490,400,000
Total MTM Derivative Contract Net Assets (Liabilities)	[10]	123,000,000.0			123,000,000.0			142,500,000
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	[10]	400,000			400,000			0
Long-term Risk Management Assets	[10]	0			0			0
Total Assets	[10]	400,000			400,000			0
Current Risk Management Liabilities	[10]	0			0			0
Long-term Risk Management Liabilities	[10]	0			0			0
Total Liabilities	[10]	0			0			0
Total MTM Derivative Contract Net Assets (Liabilities)	[10]	400,000			400,000			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	[10]	46,400,000			46,400,000			69,100,000
Long-term Risk Management Assets	[10]	200,000			200,000			0
Total Assets	[10]	46,600,000			46,600,000			69,100,000
Current Risk Management Liabilities	[10]	1,800,000			1,800,000			3,600,000
Long-term Risk Management Liabilities	[10]	900,000			900,000			100,000
Total Liabilities	[10]	2,700,000			2,700,000			3,700,000
Total MTM Derivative Contract Net Assets (Liabilities)	[10]	43,900,000			43,900,000			65,400,000
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	[10]	15,800,000			15,800,000			15,200,000
Long-term Risk Management Assets	[10]	5,400,000			5,400,000			200,000
Total Assets	[10]	21,200,000			21,200,000			15,400,000
Current Risk Management Liabilities	[10]	1,100,000			1,100,000			0
Long-term Risk Management Liabilities	[10]	0			0			0
Total Liabilities	[10]	1,100,000			1,100,000			0
Total MTM Derivative Contract Net Assets (Liabilities)	[10]	20,100,000			20,100,000			15,400,000
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	[10]	300,000			300,000			0
Long-term Risk Management Assets	[10]	0			0			0
Total Assets	[10]	300,000			300,000			0
Current Risk Management Liabilities	[10]	5,700,000			5,700,000			1,800,000
Long-term Risk Management Liabilities	[10]	45,900,000			45,900,000			37,900,000
Total Liabilities	[10]	51,600,000			51,600,000			39,700,000
Total MTM Derivative Contract Net Assets (Liabilities)	[10]	(51,300,000)			(51,300,000)			(39,700,000)
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	[10]	28,200,000			28,200,000			25,300,000
Long-term Risk Management Assets	[10]	0			0			0
Total Assets	[10]	28,200,000			28,200,000			25,300,000
Current Risk Management Liabilities	[10]	7,100,000			7,100,000			1,600,000
Long-term Risk Management Liabilities	[10]	100,000			100,000			0
Total Liabilities	[10]	7,200,000			7,200,000			1,600,000
Total MTM Derivative Contract Net Assets (Liabilities)	[10]	21,000,000.0			21,000,000.0			23,700,000
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	[10]	17,100,000			17,100,000			16,400,000
Long-term Risk Management Assets	[10]	0			0			0
Total Assets	[10]	17,100,000			17,100,000			16,400,000
Current Risk Management Liabilities	[10]	3,100,000			3,100,000			1,400,000
Long-term Risk Management Liabilities	[10]	400,000			400,000			0
Total Liabilities	[10]	3,500,000			3,500,000			1,400,000
Total MTM Derivative Contract Net Assets (Liabilities)	[10]	$ 13,600,000			$ 13,600,000			$ 15,000,000.0
Power [Member]
Commodity:
Derivative, Energy Notional Amount | MWh		262.3			262.3			226.8
Power [Member] | AEP Texas Inc. [Member]
Commodity:
Derivative, Energy Notional Amount | MWh		0.0			0.0			0.0
Power [Member] | Appalachian Power Co [Member]
Commodity:
Derivative, Energy Notional Amount | MWh		28.4			28.4			17.9
Power [Member] | Indiana Michigan Power Co [Member]
Commodity:
Derivative, Energy Notional Amount | MWh		9.0			9.0			4.2
Power [Member] | Ohio Power Co [Member]
Commodity:
Derivative, Energy Notional Amount | MWh		2.3			2.3			2.5
Power [Member] | Public Service Co Of Oklahoma [Member]
Commodity:
Derivative, Energy Notional Amount | MWh		5.6			5.6			2.9
Power [Member] | Southwestern Electric Power Co [Member]
Commodity:
Derivative, Energy Notional Amount | MWh		4.4			4.4			2.2
Natural Gas [Member]
Commodity:
Derivative, Energy Notional Amount | MMBTU		149.8			149.8			77.1
Natural Gas [Member] | AEP Texas Inc. [Member]
Commodity:
Derivative, Energy Notional Amount | MMBTU		0.0			0.0			0.0
Natural Gas [Member] | Appalachian Power Co [Member]
Commodity:
Derivative, Energy Notional Amount | MMBTU		27.3			27.3			1.9
Natural Gas [Member] | Indiana Michigan Power Co [Member]
Commodity:
Derivative, Energy Notional Amount | MMBTU		0.0			0.0			0.0
Natural Gas [Member] | Ohio Power Co [Member]
Commodity:
Derivative, Energy Notional Amount | MMBTU		0.0			0.0			0.0
Natural Gas [Member] | Public Service Co Of Oklahoma [Member]
Commodity:
Derivative, Energy Notional Amount | MMBTU		25.3			25.3			1.9
Natural Gas [Member] | Southwestern Electric Power Co [Member]
Commodity:
Derivative, Energy Notional Amount | MMBTU		13.1			13.1			2.1
Heating Oil and Gasoline [Member]
Commodity:
Derivative, Volume Notional Amount | gal		8.3			8.3			6.9
Heating Oil and Gasoline [Member] | AEP Texas Inc. [Member]
Commodity:
Derivative, Volume Notional Amount | gal		2.2			2.2			1.9
Heating Oil and Gasoline [Member] | Appalachian Power Co [Member]
Commodity:
Derivative, Volume Notional Amount | gal		1.3			1.3			1.0
Heating Oil and Gasoline [Member] | Indiana Michigan Power Co [Member]
Commodity:
Derivative, Volume Notional Amount | gal		0.8			0.8			0.7
Heating Oil and Gasoline [Member] | Ohio Power Co [Member]
Commodity:
Derivative, Volume Notional Amount | gal		1.7			1.7			1.4
Heating Oil and Gasoline [Member] | Public Service Co Of Oklahoma [Member]
Commodity:
Derivative, Volume Notional Amount | gal		1.1			1.1			0.9
Heating Oil and Gasoline [Member] | Southwestern Electric Power Co [Member]
Commodity:
Derivative, Volume Notional Amount | gal		1.2			1.2			1.0
Interest Rate Contract [Member]
Commodity:
Derivative, Notional Amount		$ 80,100,000			$ 80,100,000			$ 99,900,000
Interest Rate Contract [Member] | AEP Texas Inc. [Member]
Commodity:
Derivative, Notional Amount		0			0			0
Interest Rate Contract [Member] | Appalachian Power Co [Member]
Commodity:
Derivative, Notional Amount		0			0			0
Interest Rate Contract [Member] | Indiana Michigan Power Co [Member]
Commodity:
Derivative, Notional Amount		0			0			0
Interest Rate Contract [Member] | Ohio Power Co [Member]
Commodity:
Derivative, Notional Amount		0			0			0
Interest Rate Contract [Member] | Public Service Co Of Oklahoma [Member]
Commodity:
Derivative, Notional Amount		0			0			0
Interest Rate Contract [Member] | Southwestern Electric Power Co [Member]
Commodity:
Derivative, Notional Amount		0			0			$ 0
Vertically Integrated Utilities Revenues [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		(9,500,000)		2,100,000	2,200,000		2,200,000
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		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		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		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		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		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		0
Generation and Marketing Revenues [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		(1,400,000)		116,700,000	(290,600,000)		390,000,000.0
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		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		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		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		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		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		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		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		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		300,000	100,000		400,000
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		(9,600,000)		0	2,100,000		(100,000)
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		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		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	0		0
Other Revenues [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts				0			0
Other 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
Other 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
Other 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				1,900,000			1,900,000
Other 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
Other 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
Other 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, Fuel and Other Consumables Used for Electric Generation [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		200,000		900,000	2,200,000		3,300,000
Purchased Electricity, Fuel and Other Consumables Used for Electric Generation [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		0
Purchased Electricity, Fuel and Other Consumables Used for Electric Generation [Member] | Appalachian Power Co [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		200,000		900,000	2,100,000		3,000,000.0
Purchased Electricity, Fuel and Other Consumables Used for Electric Generation [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		100,000
Purchased Electricity, Fuel and Other Consumables Used for Electric Generation [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		0
Purchased Electricity, Fuel and Other Consumables Used for Electric Generation [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		100,000
Purchased Electricity, Fuel and Other Consumables Used for Electric Generation [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		0
Other Operation Expense [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts				1,400,000	(100,000)		3,700,000
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				400,000	0		1,100,000
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				100,000	0		300,000
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				100,000	0		400,000
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				200,000	0		600,000
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				200,000	0		500,000
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				200,000	0		600,000
Maintenance Expense [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		(400,000)		2,000,000.0	(600,000)		5,200,000
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		(100,000)		500,000	(200,000)		1,400,000
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)		200,000	(100,000)		700,000
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		0		200,000	0		500,000
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)		400,000	(100,000)		900,000
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)		200,000	(100,000)		600,000
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)		300,000	(100,000)		800,000
Regulatory Assets [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	[11]	1,200,000		4,300,000	(36,000,000.0)		49,300,000
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	[11]	500,000		0	0		100,000
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	[11]	1,200,000		0	0		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	[11]	1,700,000		100,000	(400,000)		(1,200,000)
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	[11]	500,000		4,100,000	(24,600,000)		49,000,000.0
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	[11]	(3,500,000)		0	(7,000,000.0)		3,600,000
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	[11]	(1,100,000)		100,000	(3,500,000)		(2,100,000)
Regulatory Liabilities [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	[11]	43,000,000.0		103,200,000	143,500,000		250,100,000
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	[11]	400,000		(1,500,000)	400,000		(600,000)
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	[11]	11,900,000		59,700,000	3,100,000		79,900,000
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	[11]	1,600,000		3,800,000	6,400,000		7,000,000.0
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	[11]	0		900,000	0		2,500,000
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	[11]	12,900,000		19,700,000	73,300,000		71,400,000
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	[11]	$ 12,700,000		$ 7,000,000.0	$ 58,200,000		$ 64,800,000

[1] Amounts include $(32) million and $(38) million as of September 30, 2023 and December 31, 2022, respectively, for the fair value hedge adjustment of hedged debt obligations for which hedge accounting has been discontinued.

[2] Amounts included on the Balance Sheet within Noncurrent Liabilities line item Long-term Debt.

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

[4] 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.’’

[5] The September 30, 2023 maturities of the net fair value of risk management contracts prior to cash collateral, assets/(liabilities), were as follows: Level 1 matures $(4) million in 2023 and $(9) million in periods 2024-2026; Level 2 matures $64 million in periods 2024-2026, $10 million in periods 2027-2028 and $1 million in periods 2029-2033; Level 3 matures $37 million in 2023, $118 million in periods 2024-2026, $18 million in periods 2027-2028 and $(9) million in periods 2029-2033.  Risk management commodity contracts are substantially comprised of power contracts.

[6] The December 31, 2022 maturities of the net fair value of risk management contracts prior to cash collateral, assets/(liabilities), were as follows: Level 1 matures $(7) million in 2023; Level 2 matures $182 million in 2023, $134 million in periods 2024-2026, $10 million in periods 2027-2028 and $1 million in periods 2029-2033; Level 3 matures $128 million in 2023, $6 million in periods 2024-2026, $6 million in periods 2027-2028 and $(5) million in periods 2029-2033.  Risk management commodity contracts are substantially comprised of power contracts.

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

[8] 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.”

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

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

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