Variable Interest Entities (Details) - USD ($) $ in Millions	Jun. 30, 2023		Mar. 31, 2023	Dec. 31, 2022		Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021
ASSETS
Current Assets	$ 8,041.3			$ 6,775.5
Net Property, Plant and Equipment	74,681.4			73,339.1
Other Noncurrent Assets	13,279.4			13,288.7
Total Assets	96,002.1	[1]		93,403.3
LIABILITIES AND EQUITY
Current Liabilities	13,267.1			13,266.3
Noncurrent Liabilities	58,546.7			55,968.7
Equity	24,123.6		$ 23,967.8	24,122.4		$ 24,297.0	$ 24,038.1	$ 22,680.2
Total Liabilities and Equity	96,002.1			93,403.3
Southwestern Electric Power Co [Member]
ASSETS
Current Assets	612.1			812.2
Net Property, Plant and Equipment	8,472.9			8,262.2
Other Noncurrent Assets	1,461.1			1,304.4
Total Assets	10,546.1			10,378.8
LIABILITIES AND EQUITY
Current Liabilities	784.7			947.7
Noncurrent Liabilities	5,965.9			5,756.3
Equity	3,795.5		3,765.2	3,674.8		3,611.1	3,543.8	3,149.8
Total Liabilities and Equity	10,546.1			10,378.8
Indiana Michigan Power Co [Member]
ASSETS
Current Assets	584.1			571.8
Net Property, Plant and Equipment	7,482.7			7,411.5
Other Noncurrent Assets	4,373.4			4,135.6
Total Assets	12,440.2			12,118.9
LIABILITIES AND EQUITY
Current Liabilities	678.2			1,197.1
Noncurrent Liabilities	8,641.3			7,913.5
Equity	3,120.7		3,077.3	3,008.3		2,893.3	2,849.5	2,784.7
Total Liabilities and Equity	12,440.2			12,118.9
AEP Texas Inc. [Member]
ASSETS
Current Assets	487.2			446.9
Net Property, Plant and Equipment	12,314.7			11,681.6
Other Noncurrent Assets	812.5			763.7
Total Assets	13,614.4			12,892.2
LIABILITIES AND EQUITY
Current Liabilities	923.7			1,043.8
Noncurrent Liabilities	8,356.1			7,944.1
Equity	4,334.6		4,051.3	3,904.3		3,755.6	3,664.1	3,594.2
Total Liabilities and Equity	13,614.4			12,892.2
Appalachian Power Co [Member]
ASSETS
Current Assets	1,392.6			1,259.6
Net Property, Plant and Equipment	12,674.0			12,379.2
Other Noncurrent Assets	1,391.4			1,583.4
Total Assets	15,458.0			15,222.2
LIABILITIES AND EQUITY
Current Liabilities	1,604.0			1,390.2
Noncurrent Liabilities	8,720.9			8,856.6
Equity	5,133.1		$ 5,086.9	4,975.4		$ 4,821.1	$ 4,748.0	$ 4,647.9
Total Liabilities and Equity	15,458.0			15,222.2
Sabine Mining Co [Member] | Variable Interest Entities [Member] | Southwestern Electric Power Co [Member]
ASSETS
Current Assets	5.8			108.3
Net Property, Plant and Equipment	0.0			7.2
Other Noncurrent Assets	129.7			130.0
Total Assets	135.5			245.5
LIABILITIES AND EQUITY
Current Liabilities	19.8			25.4
Noncurrent Liabilities	115.6			219.4
Equity	0.1			0.7
Total Liabilities and Equity	135.5			245.5
DCC Fuel [Member] | Variable Interest Entities [Member] | Indiana Michigan Power Co [Member]
ASSETS
Current Assets	72.5			90.2
Net Property, Plant and Equipment	129.3			179.1
Other Noncurrent Assets	63.6			94.0
Total Assets	265.4			363.3
LIABILITIES AND EQUITY
Current Liabilities	72.4			90.0
Noncurrent Liabilities	193.0			273.3
Equity	0.0			0.0
Total Liabilities and Equity	265.4			363.3
AEP Texas Central Transition Funding Co [Member] | AEP Texas Inc. [Member] | Other Noncurrent Assets [Member]
LIABILITIES AND EQUITY
Unearned Revenue	12.0			16.0
AEP Texas Central Transition Funding Co [Member] | Variable Interest Entities [Member] | AEP Texas Inc. [Member]
ASSETS
Current Assets	26.9			27.0
Net Property, Plant and Equipment	0.0			0.0
Other Noncurrent Assets	109.5	[2]		140.9	[3]
Total Assets	136.4			167.9
LIABILITIES AND EQUITY
Current Liabilities	74.5			73.2
Noncurrent Liabilities	57.5			90.4
Equity	4.4			4.3
Total Liabilities and Equity	136.4			167.9
Restoration Funding [Member] | AEP Texas Inc. [Member] | Other Noncurrent Assets [Member]
LIABILITIES AND EQUITY
Unearned Revenue	7.0			7.0
Restoration Funding [Member] | Variable Interest Entities [Member] | AEP Texas Inc. [Member]
ASSETS
Current Assets	25.4			21.1
Net Property, Plant and Equipment	0.0			0.0
Other Noncurrent Assets	157.2	[4]		168.8	[5]
Total Assets	182.6			189.9
LIABILITIES AND EQUITY
Current Liabilities	36.7			31.3
Noncurrent Liabilities	144.7			157.4
Equity	1.2			1.2
Total Liabilities and Equity	182.6			189.9
Appalachian Consumer Rate Relief Funding [Member] | Appalachian Power Co [Member] | Other Noncurrent Assets [Member]
LIABILITIES AND EQUITY
Unearned Revenue	2.0			2.0
Appalachian Consumer Rate Relief Funding [Member] | Variable Interest Entities [Member] | Appalachian Power Co [Member]
ASSETS
Current Assets	13.3			13.5
Net Property, Plant and Equipment	0.0			0.0
Other Noncurrent Assets	151.8	[6]		164.6	[7]
Total Assets	165.1			178.1
LIABILITIES AND EQUITY
Current Liabilities	29.6			29.3
Noncurrent Liabilities	133.6			146.9
Equity	1.9			1.9
Total Liabilities and Equity	165.1			178.1
AEP Credit, Inc. [Member] | Variable Interest Entities [Member]
ASSETS
Current Assets	1,186.0			1,181.0
Net Property, Plant and Equipment	0.0			0.0
Other Noncurrent Assets	9.4			9.0
Total Assets	1,195.4			1,190.0
LIABILITIES AND EQUITY
Current Liabilities	1,132.8			1,087.8
Noncurrent Liabilities	0.9			0.9
Equity	61.7			101.3
Total Liabilities and Equity	1,195.4			1,190.0
Protected Cell Of Energy Insurance Services, Inc. [Member] | Variable Interest Entities [Member]
ASSETS
Current Assets	195.1			194.5
Net Property, Plant and Equipment	0.0			0.0
Other Noncurrent Assets	0.0			0.3
Total Assets	195.1			194.8
LIABILITIES AND EQUITY
Current Liabilities	39.7			46.4
Noncurrent Liabilities	81.9			79.1
Equity	73.5			69.3
Total Liabilities and Equity	195.1			194.8
Transource Energy [Member] | Variable Interest Entities [Member]
ASSETS
Current Assets	29.3			23.5
Net Property, Plant and Equipment	496.6			482.3
Other Noncurrent Assets	5.3			2.7
Total Assets	531.2			508.5
LIABILITIES AND EQUITY
Current Liabilities	21.1			22.8
Noncurrent Liabilities	232.0			218.6
Equity	278.1			267.1
Total Liabilities and Equity	$ 531.2			508.5
Apple Blossom and Black Oak [Member] | Variable Interest Entities [Member]
ASSETS
Current Assets				8.3
Net Property, Plant and Equipment				216.5
Other Noncurrent Assets				13.6
Total Assets				238.4
LIABILITIES AND EQUITY
Current Liabilities				4.5
Noncurrent Liabilities				5.4
Equity				228.5
Total Liabilities and Equity				238.4
Santa Rita East [Member] | Variable Interest Entities [Member]
ASSETS
Current Assets				21.3
Net Property, Plant and Equipment				421.6
Other Noncurrent Assets				0.1
Total Assets				443.0
LIABILITIES AND EQUITY
Current Liabilities				9.6
Noncurrent Liabilities				7.3
Equity				426.1
Total Liabilities and Equity				443.0
Dry Lake Solar Project [Member] | Variable Interest Entities [Member]
ASSETS
Current Assets				4.0
Net Property, Plant and Equipment				142.6
Other Noncurrent Assets				0.3
Total Assets				146.9
LIABILITIES AND EQUITY
Current Liabilities				1.0
Noncurrent Liabilities				0.7
Equity				145.2
Total Liabilities and Equity				$ 146.9

[1] Amount includes Assets Held for Sale on the balance sheet. See “Planned Disposition of the Competitive Contracted Renewables Portfolio” section of Note 6 for additional information.

[2] Includes an intercompany item eliminated in consolidation of $12 million.

[3] Includes an intercompany item eliminated in consolidation of $16 million.

[4] Includes an intercompany item eliminated in consolidation of $7 million.

[5] Includes an intercompany item eliminated in consolidation of $7 million.

[6] Includes an intercompany item eliminated in consolidation of $2 million.

[7] Includes an intercompany item eliminated in consolidation of $2 million