Related Party Transactions (Details) $ in Millions		3 Months Ended	12 Months Ended
		Jun. 30, 2019 MW	Dec. 31, 2021 USD ($) MW		Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Affiliated Revenues and Purchases
Affiliated Revenues			$ 0.0		$ 0.0	$ 0.0
Related Party Transactions (Textuals)
Total Property, Plant and Equipment, Net			66,001.3	[1]	63,901.6
Charitable Contribution to AEP Foundation [Abstract]
Related Party Charitable Contribuions to AEP Foundation						50.0
Generation and Marketing [Member]
Affiliated Revenues and Purchases
Affiliated Revenues			55.4		104.6	135.8
Related Party Transactions (Textuals)
Total Property, Plant and Equipment, Net			1,864.4		1,744.1
Appalachian Power Co. to AEP Transmission Co [Member]
Joint License Agreement
Joint License Agreement			$ 2.4		0.9	0.2
Indiana Michigan Power Co to Kentucky Power Co [Member]
Related Party Transactions (Textuals)
Percentage of Power Sold under Unit Power Agreement			30.00%
AEP Generating Co to Indiana Michigan Power Co [Member]
Cook Coal Terminal
Coal Transloading Services			$ 11.0		12.0	13.0
Railcar Maintenance			$ 0.3		0.9	1.3
AEP Generating Co to Kentucky Power Co [Member]
Related Party Transactions (Textuals)
Percentage of Power Sold under Unit Power Agreement			30.00%
AEP Generating Co to Public Service Co of Oklahoma [Member]
Cook Coal Terminal
Railcar Maintenance			$ 0.4		0.7	0.8
AEP Generating Co To Southwestern Electric Power Co [Member]
Cook Coal Terminal
Railcar Maintenance			2.8		3.0	4.0
AEP Energy Partners, Inc. to AEP Texas Inc. [Member]
Oklaunion PPA between AEP Texas and AEPEP
Oklaunion Purchase Power Agreement			0.0		88.0	157.0
Indiana Michigan Power Co to AEP Transmission Co [Member]
Joint License Agreement
Joint License Agreement			4.8		3.0	1.5
Kentucky Power Co to AEP Transmission Co [Member]
Joint License Agreement
Joint License Agreement			0.5		0.4	0.3
Ohio Power Co to AEP Transmission Co [Member]
Joint License Agreement
Joint License Agreement			4.6		4.5	2.2
Public Service Co of Oklahoma to AEP Transmission Co [Member]
Joint License Agreement
Joint License Agreement			0.4		0.4	0.3
Wheeling Power Co to AEP Transmission Co [Member]
Joint License Agreement
Joint License Agreement			$ 0.2		0.2	0.1
AEP Wind Holdings LLC [Member]
Sempra Renewables LLC PPAs [Abstract]
WindGenerationMWs | MW		724
AEP Wind Holdings LLC [Member] | Generation and Marketing [Member]
Sempra Renewables LLC PPAs [Abstract]
WindGenerationMWs | MW			724
AEP Generating Co [Member]
Barging, Urea Transloading and Other Services
Expenses from Barging, Urea Transloading and Other Services			$ 7.6		10.6	14.9
AEP Generation Resources [Member]
Central Machine Shop
Billings for Services from Central Machine Shop Facility			0.4		2.9	0.8
AEP Transmission Co [Member]
Affiliated Revenues and Purchases
Affiliated Revenues			1,153.9		896.3	806.7
Sales and Purchases of Property
Related Party Sales of Property			1.4		0.2	0.0
Related Party Purchases of Property			16.7		6.0	10.2
Related Party Transactions (Textuals)
Total Property, Plant and Equipment, Net			11,935.7	[1]	10,772.8
Charitable Contribution to AEP Foundation [Abstract]
Related Party Charitable Contribuions to AEP Foundation						6.5
AEP Transmission Co [Member] | Direct Sales to East Affiliates [Member]
Affiliated Revenues and Purchases
Affiliated Revenues			0.0		0.0	0.0
AEP Transmission Co [Member] | Auction Sales to OPCo [Member]
Affiliated Revenues and Purchases
Affiliated Revenues					0.0	0.0
AEP Transmission Co [Member] | Direct Sales to AEPEP [Member]
Affiliated Revenues and Purchases
Affiliated Revenues					0.0	0.0
AEP Transmission Co [Member] | Transmission Revenues [Member]
Affiliated Revenues and Purchases
Affiliated Revenues			1,136.1		885.0	795.5
AEP Transmission Co [Member] | Other Revenues [Member]
Affiliated Revenues and Purchases
Affiliated Revenues			17.8		11.3	11.2
Appalachian Power Co [Member]
Affiliated Revenues and Purchases
Affiliated Revenues			197.9		174.7	205.3
Transmission Service Charges
PJM Net Transmission Service Charges			302.0		243.2	222.3
Barging, Urea Transloading and Other Services
Expenses from Barging, Urea Transloading and Other Services			40.1		43.7	38.9
Sales and Purchases of Property
Related Party Sales of Property			6.2		5.7	5.5
Related Party Purchases of Property			1.0		1.3	6.0
Related Party Transactions (Textuals)
Total Property, Plant and Equipment, Net			11,804.3		11,394.1
Charitable Contribution to AEP Foundation [Abstract]
Related Party Charitable Contribuions to AEP Foundation						8.9
Appalachian Power Co [Member] | Direct Sales to East Affiliates [Member]
Affiliated Revenues and Purchases
Affiliated Revenues			128.6		112.5	128.6
Appalachian Power Co [Member] | Auction Sales to OPCo [Member]
Affiliated Revenues and Purchases
Affiliated Revenues	[2]				5.3	11.4
Appalachian Power Co [Member] | Direct Sales to AEPEP [Member]
Affiliated Revenues and Purchases
Affiliated Revenues					0.0	0.0
Appalachian Power Co [Member] | Transmission Revenues [Member]
Affiliated Revenues and Purchases
Affiliated Revenues			60.3		49.1	58.5
Appalachian Power Co [Member] | Other Revenues [Member]
Affiliated Revenues and Purchases
Affiliated Revenues			9.0		7.8	6.8
Indiana Michigan Power Co [Member]
Affiliated Revenues and Purchases
Affiliated Revenues			3.8		10.5	10.5
Cost of Purchased Power from Affiliate			217.9		172.8	214.9
Transmission Service Charges
PJM Net Transmission Service Charges			186.7		145.9	143.5
Central Machine Shop
Billings for Services from Central Machine Shop Facility			2.4		3.2	2.3
Sales and Purchases of Property
Related Party Sales of Property			7.0		1.5	7.5
Related Party Purchases of Property			0.6		3.4	0.9
Related Party Transactions (Textuals)
Total Property, Plant and Equipment, Net			7,310.9		7,052.3
Charitable Contribution to AEP Foundation [Abstract]
Related Party Charitable Contribuions to AEP Foundation						9.0
Indiana Michigan Power Co [Member] | Auction Purchases From AEPEP [Member]
Affiliated Revenues and Purchases
Cost of Purchased Power from Affiliate	[2]		0.0		0.0	0.0
Indiana Michigan Power Co [Member] | Auction Purchases From AEP Energy [Member]
Affiliated Revenues and Purchases
Cost of Purchased Power from Affiliate	[2]		0.0		0.0	0.0
Indiana Michigan Power Co [Member] | Auction Purchases from AEPSC [Member]
Affiliated Revenues and Purchases
Cost of Purchased Power from Affiliate	[2]				0.0	0.0
Indiana Michigan Power Co [Member] | Direct Purchases from AEGCo [Member]
Affiliated Revenues and Purchases
Cost of Purchased Power from Affiliate			217.9		172.8	214.9
Indiana Michigan Power Co [Member] | Direct Sales to East Affiliates [Member]
Affiliated Revenues and Purchases
Affiliated Revenues			0.0		0.0	0.0
Indiana Michigan Power Co [Member] | Auction Sales to OPCo [Member]
Affiliated Revenues and Purchases
Affiliated Revenues	[2]				3.1	6.7
Indiana Michigan Power Co [Member] | Direct Sales to AEPEP [Member]
Affiliated Revenues and Purchases
Affiliated Revenues					0.0	0.0
Indiana Michigan Power Co [Member] | Transmission Revenues [Member]
Affiliated Revenues and Purchases
Affiliated Revenues			(2.5)		2.9	0.7
Indiana Michigan Power Co [Member] | Other Revenues [Member]
Affiliated Revenues and Purchases
Affiliated Revenues			6.3		4.5	3.1
Indiana Michigan Power Co [Member] | AEP Wind Holdings LLC [Member] | Generation and Marketing [Member]
Affiliated Revenues and Purchases
Cost of Purchased Power from Affiliate			10.0		11.0	9.0
Kentucky Power Co [Member]
Barging, Urea Transloading and Other Services
Expenses from Barging, Urea Transloading and Other Services			3.1		3.2	4.8
Central Machine Shop
Billings for Services from Central Machine Shop Facility			1.0		0.9	1.4
Ohio Power Co [Member]
Affiliated Revenues and Purchases
Affiliated Revenues			24.8		41.5	27.3
Cost of Purchased Power from Affiliate			51.9		119.7	156.0
Transmission Service Charges
PJM Net Transmission Service Charges			508.9		417.4	373.4
Central Machine Shop
Billings for Services from Central Machine Shop Facility			0.4		0.0	0.0
Sales and Purchases of Property
Related Party Sales of Property			9.2		7.0	7.0
Related Party Purchases of Property			1.4		1.2	3.0
Related Party Transactions (Textuals)
Total Property, Plant and Equipment, Net			7,963.0		7,452.1
Charitable Contribution to AEP Foundation [Abstract]
Related Party Charitable Contribuions to AEP Foundation						5.4
Ohio Power Co [Member] | Auction Purchases From AEPEP [Member]
Affiliated Revenues and Purchases
Cost of Purchased Power from Affiliate	[2]		26.6		51.0	64.6
Ohio Power Co [Member] | Auction Purchases From AEP Energy [Member]
Affiliated Revenues and Purchases
Cost of Purchased Power from Affiliate	[2]		25.3		58.7	69.9
Ohio Power Co [Member] | Auction Purchases from AEPSC [Member]
Affiliated Revenues and Purchases
Cost of Purchased Power from Affiliate	[2]				10.0	21.5
Ohio Power Co [Member] | Direct Purchases from AEGCo [Member]
Affiliated Revenues and Purchases
Cost of Purchased Power from Affiliate			0.0		0.0	0.0
Ohio Power Co [Member] | Direct Sales to East Affiliates [Member]
Affiliated Revenues and Purchases
Affiliated Revenues			0.0		0.0	0.0
Ohio Power Co [Member] | Auction Sales to OPCo [Member]
Affiliated Revenues and Purchases
Affiliated Revenues					0.0	0.0
Ohio Power Co [Member] | Direct Sales to AEPEP [Member]
Affiliated Revenues and Purchases
Affiliated Revenues					0.0	0.0
Ohio Power Co [Member] | Transmission Revenues [Member]
Affiliated Revenues and Purchases
Affiliated Revenues			(1.1)		16.6	7.7
Ohio Power Co [Member] | Other Revenues [Member]
Affiliated Revenues and Purchases
Affiliated Revenues			25.9		24.9	19.6
Ohio Power Co [Member] | AEP Wind Holdings LLC [Member] | Generation and Marketing [Member]
Affiliated Revenues and Purchases
Cost of Purchased Power from Affiliate			20.0		23.0	17.0
Public Service Co Of Oklahoma [Member]
Affiliated Revenues and Purchases
Affiliated Revenues			4.2		5.2	6.1
Transmission Service Charges
SPP Net Transmission Service Charges			94.7		69.7	46.9
Central Machine Shop
Billings for Services from Central Machine Shop Facility			0.7		0.9	1.1
Sales and Purchases of Property
Related Party Sales of Property			0.5		1.1	0.8
Related Party Purchases of Property			0.3		0.4	0.5
Related Party Transactions (Textuals)
Total Property, Plant and Equipment, Net			4,802.8		4,320.0
Charitable Contribution to AEP Foundation [Abstract]
Related Party Charitable Contribuions to AEP Foundation						3.4
Public Service Co Of Oklahoma [Member] | OKTCo Radial Asset Transfer [Member] | Net Book Value of Radial Assets [Member]
Related Party Transactions (Textuals)
Total Property, Plant and Equipment, Net					60.0
Public Service Co Of Oklahoma [Member] | Direct Sales to East Affiliates [Member]
Affiliated Revenues and Purchases
Affiliated Revenues			0.0		0.0	0.0
Public Service Co Of Oklahoma [Member] | Auction Sales to OPCo [Member]
Affiliated Revenues and Purchases
Affiliated Revenues					0.0	0.0
Public Service Co Of Oklahoma [Member] | Direct Sales to AEPEP [Member]
Affiliated Revenues and Purchases
Affiliated Revenues					0.0	0.0
Public Service Co Of Oklahoma [Member] | Transmission Revenues [Member]
Affiliated Revenues and Purchases
Affiliated Revenues			0.0		0.0	1.3
Public Service Co Of Oklahoma [Member] | Other Revenues [Member]
Affiliated Revenues and Purchases
Affiliated Revenues			4.2		5.2	4.8
Southwestern Electric Power Co [Member]
Affiliated Revenues and Purchases
Affiliated Revenues			41.4		41.0	36.9
Revenue from Related Parties, Net			41.0		39.0	4.9
Transmission Service Charges
SPP Net Transmission Service Charges			56.2		31.3	20.1
Central Machine Shop
Billings for Services from Central Machine Shop Facility			2.7		0.5	1.1
Sales and Purchases of Property
Related Party Sales of Property			0.4		0.8	0.2
Related Party Purchases of Property			0.3		2.8	0.7
Related Party Transactions (Textuals)
Total Property, Plant and Equipment, Net			7,400.1		7,088.2
Charitable Contribution to AEP Foundation [Abstract]
Related Party Charitable Contribuions to AEP Foundation						5.5
Southwestern Electric Power Co [Member] | Direct Sales to East Affiliates [Member]
Affiliated Revenues and Purchases
Affiliated Revenues			0.0		0.0	0.0
Southwestern Electric Power Co [Member] | Auction Sales to OPCo [Member]
Affiliated Revenues and Purchases
Affiliated Revenues					0.0	0.0
Southwestern Electric Power Co [Member] | Direct Sales to AEPEP [Member]
Affiliated Revenues and Purchases
Affiliated Revenues					0.0	(0.1)
Southwestern Electric Power Co [Member] | Transmission Revenues [Member]
Affiliated Revenues and Purchases
Affiliated Revenues			39.6		37.4	3.6
Southwestern Electric Power Co [Member] | Other Revenues [Member]
Affiliated Revenues and Purchases
Affiliated Revenues			1.4		1.6	1.4
Southwestern Electric Power Co [Member] | AEP Wind Holdings LLC [Member] | Generation and Marketing [Member]
Affiliated Revenues and Purchases
Cost of Purchased Power from Affiliate			14.0		14.0	10.0
Wheeling Power Co [Member] [Domain]
Barging, Urea Transloading and Other Services
Expenses from Barging, Urea Transloading and Other Services			3.2		3.3	4.8
AEP Texas Inc. [Member]
Affiliated Revenues and Purchases
Affiliated Revenues			3.9		90.8	160.5
ERCOT Transmission Service Charges
Billings from ETT for ERCOT Wholesale Transmission Services			28.0		28.0	27.0
Sales and Purchases of Property
Related Party Sales of Property			0.4		0.9	0.9
Related Party Purchases of Property			$ 0.4		1.5	0.3
Related Party Transactions (Textuals)
Jointly Owned Utility Plant, Proportionate Ownership Share			54.69%
Total Property, Plant and Equipment, Net			$ 10,635.4		9,813.6
Charitable Contribution to AEP Foundation [Abstract]
Related Party Charitable Contribuions to AEP Foundation						6.2
AEP Texas Inc. [Member] | Direct Sales to East Affiliates [Member]
Affiliated Revenues and Purchases
Affiliated Revenues			0.0		0.0	0.0
AEP Texas Inc. [Member] | Auction Sales to OPCo [Member]
Affiliated Revenues and Purchases
Affiliated Revenues					0.0	0.0
AEP Texas Inc. [Member] | Direct Sales to AEPEP [Member]
Affiliated Revenues and Purchases
Affiliated Revenues					87.5	157.2
AEP Texas Inc. [Member] | Transmission Revenues [Member]
Affiliated Revenues and Purchases
Affiliated Revenues			0.0		0.0	0.0
AEP Texas Inc. [Member] | Other Revenues [Member]
Affiliated Revenues and Purchases
Affiliated Revenues			$ 3.9		$ 3.3	$ 3.3

[1] Amount excludes $2.3 billion and $165 million for AEP and AEPTCo, respectively, of Property, Plant and Equipment - Net classified as Assets Held for Sale on the balance sheet. See “Disposition of KPCo and KTCo” section of Note 7 for additional information.

[2] Refer to the Ohio Auctions section below for further information regarding these amounts.