Variable Interest Entities (Details) - USD ($) $ in Millions	Mar. 31, 2023		Dec. 31, 2022		Mar. 31, 2022	Dec. 31, 2021
ASSETS
Current Assets	$ 7,798.2		$ 6,775.5
Net Property, Plant and Equipment	73,347.0		73,339.1
Other Noncurrent Assets	13,372.7		13,288.7
Total Assets	94,517.9	[1]	93,403.3
LIABILITIES AND EQUITY
Current Liabilities	12,621.7		13,266.3
Noncurrent Liabilities	57,871.8		55,968.7
Equity	23,967.8		24,122.4		$ 24,038.1	$ 22,680.2
Total Liabilities and Equity	94,517.9		93,403.3
Southwestern Electric Power Co [Member]
ASSETS
Current Assets	678.5		812.2
Net Property, Plant and Equipment	8,342.6		8,262.2
Other Noncurrent Assets	1,375.5		1,304.4
Total Assets	10,396.6		10,378.8
LIABILITIES AND EQUITY
Current Liabilities	662.4		947.7
Noncurrent Liabilities	5,969.0		5,756.3
Equity	3,765.2		3,674.8		3,543.8	3,149.8
Total Liabilities and Equity	10,396.6		10,378.8
Indiana Michigan Power Co [Member]
ASSETS
Current Assets	571.4		571.8
Net Property, Plant and Equipment	7,416.9		7,411.5
Other Noncurrent Assets	4,254.0		4,135.6
Total Assets	12,242.3		12,118.9
LIABILITIES AND EQUITY
Current Liabilities	634.8		1,197.1
Noncurrent Liabilities	8,530.2		7,913.5
Equity	3,077.3		3,008.3		2,849.5	2,784.7
Total Liabilities and Equity	12,242.3		12,118.9
AEP Texas Inc. [Member]
ASSETS
Current Assets	429.1		446.9
Net Property, Plant and Equipment	12,008.0		11,681.6
Other Noncurrent Assets	835.1		763.7
Total Assets	13,272.2		12,892.2
LIABILITIES AND EQUITY
Current Liabilities	1,280.1		1,043.8
Noncurrent Liabilities	7,940.8		7,944.1
Equity	4,051.3		3,904.3		3,664.1	3,594.2
Total Liabilities and Equity	13,272.2		12,892.2
Appalachian Power Co [Member]
ASSETS
Current Assets	1,299.0		1,259.6
Net Property, Plant and Equipment	12,506.1		12,379.2
Other Noncurrent Assets	1,451.3		1,583.4
Total Assets	15,256.4		15,222.2
LIABILITIES AND EQUITY
Current Liabilities	1,350.1		1,390.2
Noncurrent Liabilities	8,819.4		8,856.6
Equity	5,086.9		4,975.4		$ 4,748.0	$ 4,647.9
Total Liabilities and Equity	15,256.4		15,222.2
Sabine Mining Co [Member] | Variable Interest Entities [Member] | Southwestern Electric Power Co [Member]
ASSETS
Current Assets	23.0		108.3
Net Property, Plant and Equipment	0.0		7.2
Other Noncurrent Assets	135.1		130.0
Total Assets	158.1		245.5
LIABILITIES AND EQUITY
Current Liabilities	33.5		25.4
Noncurrent Liabilities	124.2		219.4
Equity	0.4		0.7
Total Liabilities and Equity	158.1		245.5
DCC Fuel [Member] | Variable Interest Entities [Member] | Indiana Michigan Power Co [Member]
ASSETS
Current Assets	84.3		90.2
Net Property, Plant and Equipment	154.3		179.1
Other Noncurrent Assets	76.0		94.0
Total Assets	314.6		363.3
LIABILITIES AND EQUITY
Current Liabilities	84.2		90.0
Noncurrent Liabilities	230.4		273.3
Equity	0.0		0.0
Total Liabilities and Equity	314.6		363.3
AEP Texas Central Transition Funding Co [Member] | AEP Texas Inc. [Member] | Other Noncurrent Assets [Member]
LIABILITIES AND EQUITY
Unearned Revenue	14.0		16.0
AEP Texas Central Transition Funding Co [Member] | Variable Interest Entities [Member] | AEP Texas Inc. [Member]
ASSETS
Current Assets	43.0		27.0
Net Property, Plant and Equipment	0.0		0.0
Other Noncurrent Assets	125.2	[2]	140.9	[3]
Total Assets	168.2		167.9
LIABILITIES AND EQUITY
Current Liabilities	74.3		73.2
Noncurrent Liabilities	89.6		90.4
Equity	4.3		4.3
Total Liabilities and Equity	168.2		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	13.4		21.1
Net Property, Plant and Equipment	0.0		0.0
Other Noncurrent Assets	163.0	[4]	168.8	[5]
Total Assets	176.4		189.9
LIABILITIES AND EQUITY
Current Liabilities	30.5		31.3
Noncurrent Liabilities	144.7		157.4
Equity	1.2		1.2
Total Liabilities and Equity	176.4		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	6.1		13.5
Net Property, Plant and Equipment	0.0		0.0
Other Noncurrent Assets	157.4	[6]	164.6	[7]
Total Assets	163.5		178.1
LIABILITIES AND EQUITY
Current Liabilities	28.1		29.3
Noncurrent Liabilities	133.5		146.9
Equity	1.9		1.9
Total Liabilities and Equity	163.5		178.1
AEP Credit, Inc. [Member] | Variable Interest Entities [Member]
ASSETS
Current Assets	1,092.6		1,181.0
Net Property, Plant and Equipment	0.0		0.0
Other Noncurrent Assets	8.9		9.0
Total Assets	1,101.5		1,190.0
LIABILITIES AND EQUITY
Current Liabilities	1,043.2		1,087.8
Noncurrent Liabilities	0.9		0.9
Equity	57.4		101.3
Total Liabilities and Equity	1,101.5		1,190.0
Protected Cell Of Energy Insurance Services, Inc. [Member] | Variable Interest Entities [Member]
ASSETS
Current Assets	203.2		194.5
Net Property, Plant and Equipment	0.0		0.0
Other Noncurrent Assets	0.0		0.3
Total Assets	203.2		194.8
LIABILITIES AND EQUITY
Current Liabilities	50.2		46.4
Noncurrent Liabilities	78.0		79.1
Equity	75.0		69.3
Total Liabilities and Equity	203.2		194.8
Transource Energy [Member] | Variable Interest Entities [Member]
ASSETS
Current Assets	22.1		23.5
Net Property, Plant and Equipment	495.1		482.3
Other Noncurrent Assets	6.8		2.7
Total Assets	524.0		508.5
LIABILITIES AND EQUITY
Current Liabilities	33.4		22.8
Noncurrent Liabilities	219.0		218.6
Equity	271.6		267.1
Total Liabilities and Equity	$ 524.0		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 $14 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