Acquisitions and Dispositions (Details)		3 Months Ended			6 Months Ended
		Jun. 30, 2022 USD ($) MW	Jun. 30, 2021 USD ($)	Mar. 31, 2021 USD ($)	Jun. 30, 2022 USD ($) MW	Jun. 30, 2021 USD ($)	Dec. 31, 2021 USD ($)
Obligations Under Operating Leases		$ 549,600,000			$ 549,600,000		$ 492,800,000
Asset Retirement Obligation, Liabilities Settled	[1],[2],[3],[4],[5]				16,500,000
Additional Paid in Capital		7,984,000,000			7,984,000,000		7,172,600,000
Property, Plant and Equipment		24,465,900,000			24,465,900,000		23,088,100,000
Noncontrolling Interests		241,000,000.0			241,000,000.0		247,000,000.0
Customers		930,300,000			930,300,000		720,900,000
Materials and Supplies		748,600,000			748,600,000		681,300,000
Property, Plant and Equipment, Net		68,708,200,000			68,708,200,000		66,001,300,000
Regulatory Assets, Noncurrent		4,157,700,000			4,157,700,000		4,142,300,000
Assets Held for Sale		2,945,700,000			2,945,700,000		2,919,700,000
Accounts Payable, Current		2,198,200,000			2,198,200,000		2,054,600,000
Long-term Debt Due Within One Year	[6]	2,476,700,000			2,476,700,000		2,153,800,000
Customer Deposits, Current		483,100,000			483,100,000		321,600,000
Deferred Tax Liabilities, Net, Noncurrent		8,481,000,000			8,481,000,000		8,202,500,000
Long-term Debt	[7]	32,982,700,000			32,982,700,000		31,300,700,000
Regulatory Liabilities and Deferred Investment Tax Credits		8,057,200,000			8,057,200,000		8,686,300,000
Liabilities Held for Sale		1,900,300,000			1,900,300,000		1,880,900,000
Loss on the Expected Sale of the Kentucky Operations		68,800,000	$ 0		68,800,000	$ 0
Proceeds from Sale of Property, Plant, and Equipment					208,500,000	13,200,000
Gain (Loss) on Disposition of Assets		(116,300,000)	0		$ (116,300,000)	0
Proceeds of Mineral Rights Sale
Proceeds from Sale of Property, Plant, and Equipment		120,000,000
Gain (Loss) on Disposition of Assets		$ 116,000,000
BP Wind Energy
Wind Generation MWs | MW		724
Loss on the Expected Sale of the Kentucky Operations		$ 186,000,000
Equity Method Investment, Ownership Percentage		50.00%			50.00%
Dry Lake Solar Project
Payments to Acquire Property, Plant, and Equipment					$ 0	114,300,000
North Central Wind Energy Facilities
Payments to Acquire Property, Plant, and Equipment					$ 1,207,300,000	270,000,000.0
Mitchell Power Plant
Approximate OVEC Generating Capacity (MWs) | MW		1,560			1,560
NBV Mitchell Including CWIP and Inventory		$ 584,000,000			$ 584,000,000
Dry Lake Solar Project
Percentage of an Asset Acquired		75.00%			75.00%
Noncash or Part Noncash Acquisition, Other Assets Acquired				$ 18,900,000
Dry Lake Solar Project | Noncontrolling Interest [Member]
Noncash or Part Noncash Acquisition, Other Assets Acquired				$ 18,900,000
North Central Wind Energy Facilities
Payments to Acquire Property, Plant, and Equipment		$ 2,000,000,000
Generation And Marketing [Member] | Dry Lake Solar Project
Payments to Acquire Property, Plant, and Equipment					$ 114,000,000
Generation And Marketing [Member] | Dry Lake Solar Project | Payment at Closing
Payments to Acquire Property, Plant, and Equipment					103,000,000
Generation And Marketing [Member] | Dry Lake Solar Project | Payment When Put in Service
Payments to Acquire Property, Plant, and Equipment					11,000,000
Generation And Marketing [Member] | Dry Lake Solar Project
Property, Plant and Equipment		144,000,000			144,000,000
Noncontrolling Interests		35,000,000			$ 35,000,000
Solar Generation MWs | MW					100
Generation And Marketing [Member] | Dry Lake Solar Project | Noncontrolling Interest [Member]
Noncash or Part Noncash Acquisition, Other Assets Acquired					$ 16,000,000
Vertically Integrated Utilities [Member]
Enterprise Value		2,850,000,000			2,850,000,000
Vertically Integrated Utilities [Member] | Kentucky Power Company and Kentucky Transmission Company
Customers		87,100,000			87,100,000		33,200,000
Materials and Supplies		37,400,000			37,400,000		30,600,000
Property, Plant and Equipment, Net		2,358,000,000			2,358,000,000		2,302,700,000
Regulatory Assets, Noncurrent		484,500,000			484,500,000		484,700,000
Disposal Group, Including Discontinued Operation, Other Assets		47,500,000			47,500,000		68,500,000
Disposal Group, Including Discontinued Operation, Assets		3,014,500,000			3,014,500,000		2,919,700,000
Assets Held for Sale		2,945,700,000			2,945,700,000		2,919,700,000
Accounts Payable, Current		74,300,000			74,300,000		53,400,000
Long-term Debt Due Within One Year		415,000,000.0			415,000,000.0		200,000,000.0
Customer Deposits, Current		38,000,000.0			38,000,000.0		32,400,000
Deferred Tax Liabilities, Net, Noncurrent		453,500,000			453,500,000		441,600,000
Long-term Debt		688,300,000			688,300,000		903,100,000
Regulatory Liabilities and Deferred Investment Tax Credits		140,100,000			140,100,000		148,100,000
Disposal Group, Including Discontinued Operation, Other Liabilities, Current		91,100,000			91,100,000		102,300,000
Liabilities Held for Sale		1,900,300,000			1,900,300,000		1,880,900,000
Loss on the Expected Sale of the Kentucky Operations		$ (68,800,000)	0
Vertically Integrated Utilities [Member] | Sundance [Member]
Wind Generation MWs | MW		199
Vertically Integrated Utilities [Member] | Sundance [Member] | North Central Wind Energy Facilities
Payments to Acquire Property, Plant, and Equipment					270,000,000
Vertically Integrated Utilities [Member] | Maverick [Member]
Wind Generation MWs | MW		287
Vertically Integrated Utilities [Member] | Maverick [Member] | North Central Wind Energy Facilities
Payments to Acquire Property, Plant, and Equipment		$ 383,000,000
Vertically Integrated Utilities [Member] | Traverse [Member]
Wind Generation MWs | MW		998
Vertically Integrated Utilities [Member] | Traverse [Member] | North Central Wind Energy Facilities
Payments to Acquire Property, Plant, and Equipment					$ 1,200,000,000
Vertically Integrated Utilities [Member] | North Central Wind Energy Facilities
Wind Generation MWs | MW					1,484
Transmission Operations [Member]
Enterprise Value		$ 2,850,000,000			$ 2,850,000,000
Transmission Operations [Member] | Kentucky Transmission Company
Customers		1,900,000			1,900,000		1,500,000
Materials and Supplies		0			0		0
Property, Plant and Equipment, Net		166,900,000			166,900,000		165,300,000
Regulatory Assets, Noncurrent		0			0		0
Disposal Group, Including Discontinued Operation, Other Assets		2,700,000			2,700,000		1,100,000
Disposal Group, Including Discontinued Operation, Assets		171,500,000			171,500,000		167,900,000
Assets Held for Sale		171,500,000			171,500,000		167,900,000
Accounts Payable, Current		1,200,000			1,200,000		1,100,000
Long-term Debt Due Within One Year		0			0		0
Customer Deposits, Current		0			0		0
Deferred Tax Liabilities, Net, Noncurrent		16,200,000			16,200,000		15,400,000
Long-term Debt		0			0		0
Regulatory Liabilities and Deferred Investment Tax Credits		7,900,000			7,900,000		7,600,000
Disposal Group, Including Discontinued Operation, Other Liabilities, Current		2,300,000			2,300,000		3,500,000
Liabilities Held for Sale		$ 27,600,000			$ 27,600,000		27,600,000
Loss on the Expected Sale of the Kentucky Operations			$ 0
Public Service Co Of Oklahoma [Member]
Percentage of an Asset Acquired		45.50%			45.50%
Obligations Under Operating Leases		$ 100,400,000			$ 100,400,000		62,200,000
Asset Retirement Obligation, Liabilities Settled	[3],[4]				500,000
Additional Paid in Capital		1,041,200,000			1,041,200,000		1,039,000,000
Property, Plant and Equipment		2,382,900,000			2,382,900,000		1,802,400,000
Payments to Acquire Property, Plant, and Equipment					(549,300,000)	(122,800,000)
Customers		45,300,000			45,300,000		41,500,000
Materials and Supplies		73,600,000			73,600,000		56,200,000
Property, Plant and Equipment, Net		5,455,000,000			5,455,000,000		4,802,800,000
Regulatory Assets, Noncurrent		1,043,800,000			1,043,800,000		1,037,400,000
Accounts Payable, Current		229,800,000			229,800,000		157,400,000
Long-term Debt Due Within One Year		625,500,000			625,500,000		125,500,000
Customer Deposits, Current		58,800,000			58,800,000		56,200,000
Deferred Tax Liabilities, Net, Noncurrent		785,400,000			785,400,000		782,300,000
Long-term Debt		1,788,300,000			1,788,300,000		1,788,000,000
Regulatory Liabilities and Deferred Investment Tax Credits		830,700,000			830,700,000		835,300,000
Public Service Co Of Oklahoma [Member] | Vertically Integrated Utilities [Member] | North Central Wind Energy Facilities
Obligations Under Operating Leases		70,600,000			70,600,000		30,600,000
Property, Plant and Equipment		889,000,000			889,000,000
Public Service Co Of Oklahoma [Member] | Vertically Integrated Utilities [Member] | North Central Wind Energy Facilities | Sundance [Member]
Obligations Under Operating Leases		12,600,000			12,600,000		12,600,000
Public Service Co Of Oklahoma [Member] | Vertically Integrated Utilities [Member] | North Central Wind Energy Facilities | Maverick [Member]
Obligations Under Operating Leases		18,000,000.0			18,000,000.0		18,000,000.0
Public Service Co Of Oklahoma [Member] | Vertically Integrated Utilities [Member] | North Central Wind Energy Facilities | Traverse [Member]
Obligations Under Operating Leases		$ 40,000,000.0			$ 40,000,000.0		0
Southwestern Electric Power Co [Member]
Percentage of an Asset Acquired		54.50%			54.50%
Obligations Under Operating Leases		$ 122,600,000			$ 122,600,000		77,700,000
Asset Retirement Obligation, Liabilities Settled	[2],[3],[4]				10,900,000
Additional Paid in Capital		1,444,400,000			1,444,400,000		1,092,200,000
Property, Plant and Equipment		5,436,000,000			5,436,000,000		4,734,500,000
Noncontrolling Interests		1,500,000			1,500,000		(100,000)
Payments to Acquire Property, Plant, and Equipment					(658,000,000.0)	$ (147,100,000)
Customers		34,900,000			34,900,000		35,800,000
Materials and Supplies		85,200,000			85,200,000		81,900,000
Property, Plant and Equipment, Net		8,105,100,000			8,105,100,000		7,400,100,000
Regulatory Assets, Noncurrent		987,200,000			987,200,000		1,005,300,000
Accounts Payable, Current		204,600,000			204,600,000		163,600,000
Long-term Debt Due Within One Year		6,200,000			6,200,000		6,200,000
Customer Deposits, Current		65,100,000			65,100,000		62,400,000
Deferred Tax Liabilities, Net, Noncurrent		1,099,000,000			1,099,000,000		1,087,600,000
Long-term Debt		3,387,200,000			3,387,200,000		3,389,000,000
Regulatory Liabilities and Deferred Investment Tax Credits		815,300,000			815,300,000		806,900,000
Southwestern Electric Power Co [Member] | Vertically Integrated Utilities [Member] | North Central Wind Energy Facilities
Obligations Under Operating Leases		84,500,000			84,500,000		36,700,000
Property, Plant and Equipment		1,100,000,000			1,100,000,000
Southwestern Electric Power Co [Member] | Vertically Integrated Utilities [Member] | North Central Wind Energy Facilities | Sundance [Member]
Obligations Under Operating Leases		15,000,000.0			15,000,000.0		15,100,000
Southwestern Electric Power Co [Member] | Vertically Integrated Utilities [Member] | North Central Wind Energy Facilities | Maverick [Member]
Obligations Under Operating Leases		21,600,000			21,600,000		21,600,000
Southwestern Electric Power Co [Member] | Vertically Integrated Utilities [Member] | North Central Wind Energy Facilities | Traverse [Member]
Obligations Under Operating Leases		$ 47,900,000			$ 47,900,000		0
Kentucky Power Co [Member] | Mitchell Power Plant
Ownership Interest in Mitchell Power Plant		50.00%			50.00%
Wheeling Power Company | Mitchell Power Plant
Ownership Interest in Mitchell Power Plant		50.00%			50.00%
AEP Transmission Co [Member]
Obligations Under Operating Leases		$ 1,900,000			$ 1,900,000		1,300,000
Customers		43,800,000			43,800,000		22,500,000
Materials and Supplies		11,500,000			11,500,000		9,300,000
Property, Plant and Equipment, Net		12,449,200,000			12,449,200,000		11,935,700,000
Regulatory Assets, Noncurrent		4,600,000			4,600,000		8,500,000
Assets Held for Sale		171,500,000			171,500,000		167,900,000
Accounts Payable, Current		314,000,000.0			314,000,000.0		460,100,000
Long-term Debt Due Within One Year		104,000,000.0			104,000,000.0		104,000,000.0
Deferred Tax Liabilities, Net, Noncurrent		1,006,200,000			1,006,200,000		962,900,000
Long-term Debt		4,781,600,000			4,781,600,000		4,239,900,000
Regulatory Liabilities and Deferred Investment Tax Credits		679,100,000			679,100,000		644,100,000
Liabilities Held for Sale		$ 27,600,000			27,600,000		$ 27,600,000
AEP Transmission Co [Member] | Transmission Operations [Member]
Proceeds from Divestiture of Businesses					$ 1,400,000,000

[1] Includes $18 million and $18 million as of June 30, 2022 and December 31, 2021, respectively, of ARO classified as Liabilities Held for Sale on the balance sheets. See “Disposition of KPCo and KTCo” section of Note 6 for additional information.

[2] Includes ARO related to Sabine and DHLC.

[3] Includes ARO related to asbestos removal.

[4] Includes ARO related to ash disposal facilities.

[5] Includes ARO related to nuclear decommissioning costs for the Cook Plant of $1.96 billion and $1.93 billion as of June 30, 2022 and December 31, 2021, respectively.

[6] Amount excludes $415 million and $200 million as of June 30, 2022 and December 31, 2021, respectively, of Long-term Debt Due Within One Year classified as Liabilities Held for Sale on the balance sheet. See “Disposition of KPCo and KTCo” section of Note 6 for additional information.

[7] Amount excludes $688 million and $903 million as of June 30, 2022 and December 31, 2021, respectively, of Long-term Debt classified as Liabilities Held for Sale on the balance sheet. See “Disposition of KPCo and KTCo” section of Note 6 for additional information.