Property, Plant and Equipment (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2021		Dec. 31, 2020		Dec. 31, 2019
Depreciation, Depletion and Amortization
Property, Plant and Equipment, Generation		$ 23,088.1		$ 23,133.9
Property, Plant and Equipment, Transmission		29,911.1		27,886.7
Property, Plant and Equipment, Distribution		24,440.0		23,972.1
Property, Plant and Equipment, Other		5,682.9		5,294.6
Property, Plant and Equipment, Construction Work in Progress		3,684.3		4,025.7
Accumulated Depreciation		20,805.1		20,411.4
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		66,001.3	[1]	63,901.6
Assets Held for Sale		2,919.7		0.0
Asset Retirement Obligations (ARO)
Beginning Balance	[3],[4],[5],[6]	2,516.7	[2]	2,418.9
Accretion Expense	[3],[4],[5],[6]	105.0	[2]	102.4
Liabilities Incurred	[3],[4],[5],[6]	22.8	[2]	0.3
Liabilities Settled	[3],[4],[5],[6]	(41.4)	[2]	(188.0)
Revisions in Cash Flow Estimates	[3],[4],[5],[6],[7]	138.6	[2]	183.1
Ending Balance	[3],[4],[5],[6]	2,741.7	[2]	2,516.7	[2]	$ 2,418.9
Asset Retirement Obligations (ARO) Liability for Nuclear Decommissioning of the Cook Plant		1,930.0		1,800.0
Liabilities Held for Sale		1,880.9		0.0
Allowance for Funds Used During Construction (AFUDC) and Interest Capitalization
Allowance for Equity Funds Used During Construction		139.7		148.1		168.4
Allowance for Borrowed Funds Used During Construction		53.8		66.0		88.7
Jointly-owned Electric Facilities
Utility Plant in Service		2,589.4		2,916.7
Construction Work in Progress		16.5		14.1
Accumulated Depreciation		947.4		1,109.7
Asset Impairments and Other Related Charges		11.6		0.0		156.4
Kentucky Power Co [Member]
Depreciation, Depletion and Amortization
Assets Held for Sale		2,300.0
Kentucky Power Co [Member]
Asset Retirement Obligations (ARO)
Liabilities Held for Sale		18.0
AEP Texas Inc. [Member]
Depreciation, Depletion and Amortization
Property, Plant and Equipment, Transmission		5,849.9		5,279.6
Property, Plant and Equipment, Distribution		4,917.2		4,580.8
Property, Plant and Equipment, Other		961.1		868.4
Property, Plant and Equipment, Construction Work in Progress		551.3		614.1
Accumulated Depreciation		1,644.1		1,529.3
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		10,635.4		9,813.6
Asset Retirement Obligations (ARO)
Beginning Balance	[4],[5]	4.6		29.1
Accretion Expense	[4],[5]	0.2		0.8
Liabilities Incurred	[4],[5]	0.0		0.0
Liabilities Settled	[4],[5]	(0.4)		(8.5)
Revisions in Cash Flow Estimates	[4],[5],[7]	0.0		(16.8)
Ending Balance	[4],[5]	4.4		4.6		29.1
Allowance for Funds Used During Construction (AFUDC) and Interest Capitalization
Allowance for Equity Funds Used During Construction		21.5		19.4		15.2
Allowance for Borrowed Funds Used During Construction		$ 10.5		12.5		20.0
Jointly-owned Electric Facilities
Percent of Ownership		54.69%
Asset Impairments and Other Related Charges		$ 0.0		0.0		32.5
AEP Transmission Co [Member]
Depreciation, Depletion and Amortization
Property, Plant and Equipment, Transmission		10,886.3		9,593.5
Property, Plant and Equipment, Other		427.4		329.5
Property, Plant and Equipment, Construction Work in Progress		1,394.8		1,422.6
Accumulated Depreciation		772.8		572.8
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		11,935.7	[1]	10,772.8
Assets Held for Sale		167.9		0.0
Asset Retirement Obligations (ARO)
Liabilities Held for Sale		27.6		0.0
Allowance for Funds Used During Construction (AFUDC) and Interest Capitalization
Allowance for Equity Funds Used During Construction		67.2		74.0		84.3
Allowance for Borrowed Funds Used During Construction		21.0		25.5		32.2
AEP Transmission Co [Member] | Kentucky Transmission Company
Depreciation, Depletion and Amortization
Assets Held for Sale		165.0
Appalachian Power Co [Member]
Depreciation, Depletion and Amortization
Property, Plant and Equipment, Generation		6,683.9		6,633.7
Property, Plant and Equipment, Transmission		4,322.4		3,900.5
Property, Plant and Equipment, Distribution		4,683.3		4,464.3
Property, Plant and Equipment, Other		696.6		627.2
Property, Plant and Equipment, Construction Work in Progress		469.9		484.6
Accumulated Depreciation		5,051.8		4,716.2
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		11,804.3		11,394.1
Asset Retirement Obligations (ARO)
Beginning Balance	[4],[5]	313.1		111.1
Accretion Expense	[4],[5]	13.7		8.9
Liabilities Incurred	[4],[5]	0.0		0.0
Liabilities Settled	[4],[5]	(6.9)		(7.8)
Revisions in Cash Flow Estimates	[4],[5],[7]	84.7		200.9
Ending Balance	[4],[5]	404.6		313.1		111.1
Allowance for Funds Used During Construction (AFUDC) and Interest Capitalization
Allowance for Equity Funds Used During Construction		15.6		14.6		16.6
Allowance for Borrowed Funds Used During Construction		7.5		7.9		9.3
Jointly-owned Electric Facilities
Asset Impairments and Other Related Charges		0.0		0.0		92.9
Indiana Michigan Power Co [Member]
Depreciation, Depletion and Amortization
Property, Plant and Equipment, Generation		5,531.8		5,264.7
Property, Plant and Equipment, Transmission		1,783.1		1,696.4
Property, Plant and Equipment, Distribution		2,800.1		2,594.6
Property, Plant and Equipment, Other		792.9		686.7
Property, Plant and Equipment, Construction Work in Progress		302.8		362.4
Accumulated Depreciation		3,899.8		3,552.5
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		7,310.9		7,052.3
Asset Retirement Obligations (ARO)
Beginning Balance	[4],[5],[6]	1,813.8		1,748.6
Accretion Expense	[4],[5],[6]	72.9		70.2
Liabilities Incurred	[4],[5],[6]	0.3		0.1
Liabilities Settled	[4],[5],[6]	(0.1)		(0.2)
Revisions in Cash Flow Estimates	[4],[5],[6],[7]	59.4		(4.9)
Ending Balance	[4],[5],[6]	1,946.3		1,813.8		1,748.6
Asset Retirement Obligations (ARO) Liability for Nuclear Decommissioning of the Cook Plant		1,930.0		1,800.0
Fair Value of Legally Restricted Assets		3,540.0		2,980.0
Allowance for Funds Used During Construction (AFUDC) and Interest Capitalization
Allowance for Equity Funds Used During Construction		12.8		11.5		19.4
Allowance for Borrowed Funds Used During Construction		5.1		5.7		8.9
Ohio Power Co [Member]
Depreciation, Depletion and Amortization
Property, Plant and Equipment, Transmission		2,992.8		2,831.9
Property, Plant and Equipment, Distribution		6,070.6		5,708.3
Property, Plant and Equipment, Other		992.9		899.6
Property, Plant and Equipment, Construction Work in Progress		365.0		362.3
Accumulated Depreciation		2,458.3		2,350.0
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		7,963.0		7,452.1
Asset Retirement Obligations (ARO)
Beginning Balance	[4]	1.9		1.8
Accretion Expense	[4]	0.1		0.1
Liabilities Incurred	[4]	0.0		0.0
Liabilities Settled	[4]	(0.1)		0.0
Revisions in Cash Flow Estimates	[4],[7]	0.0		0.0
Ending Balance	[4]	1.9		1.9		1.8
Allowance for Funds Used During Construction (AFUDC) and Interest Capitalization
Allowance for Equity Funds Used During Construction		10.8		12.5		18.2
Allowance for Borrowed Funds Used During Construction		4.7		6.2		6.7
Public Service Co Of Oklahoma [Member]
Depreciation, Depletion and Amortization
Property, Plant and Equipment, Generation		1,802.4		1,480.7
Property, Plant and Equipment, Transmission		1,107.7		1,069.9
Property, Plant and Equipment, Distribution		3,004.9		2,853.0
Property, Plant and Equipment, Other		437.0		393.3
Property, Plant and Equipment, Construction Work in Progress		156.0		128.7
Accumulated Depreciation		1,705.2		1,605.6
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		4,802.8		4,320.0
Asset Retirement Obligations (ARO)
Beginning Balance	[4],[5]	47.4		52.2
Accretion Expense	[4],[5]	3.3		3.1
Liabilities Incurred	[4],[5]	7.6		0.0
Liabilities Settled	[4],[5]	(0.7)		(3.1)
Revisions in Cash Flow Estimates	[4],[5],[7]	0.0		(4.8)
Ending Balance	[4],[5]	57.6		47.4		52.2
Allowance for Funds Used During Construction (AFUDC) and Interest Capitalization
Allowance for Equity Funds Used During Construction		2.4		4.0		2.7
Allowance for Borrowed Funds Used During Construction		0.7		2.0		1.9
Southwestern Electric Power Co [Member]
Depreciation, Depletion and Amortization
Property, Plant and Equipment, Generation		4,734.5		4,681.4
Property, Plant and Equipment, Transmission		2,316.9		2,165.7
Property, Plant and Equipment, Distribution		2,514.3		2,382.5
Property, Plant and Equipment, Other		764.0		788.8
Property, Plant and Equipment, Construction Work in Progress		240.7		228.3
Accumulated Depreciation		3,170.3		3,158.5
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		7,400.1		7,088.2
Asset Retirement Obligations (ARO)
Beginning Balance	[3],[4],[5]	222.1		212.2
Accretion Expense	[3],[4],[5]	9.8		10.7
Liabilities Incurred	[3],[4],[5]	9.2		0.0
Liabilities Settled	[3],[4],[5]	(20.9)		(10.9)
Revisions in Cash Flow Estimates	[3],[4],[5],[7]	2.5		10.1
Ending Balance	[3],[4],[5]	222.7		222.1		212.2
Allowance for Funds Used During Construction (AFUDC) and Interest Capitalization
Allowance for Equity Funds Used During Construction		7.0		7.7		6.8
Allowance for Borrowed Funds Used During Construction		3.0		3.9		4.0
Jointly-owned Electric Facilities
Utility Plant in Service		2,965.6		2,916.7
Construction Work in Progress		16.5		14.1
Accumulated Depreciation		952.8		1,109.7
Asset Impairments and Other Related Charges		11.6		$ 0.0		$ 0.0
Southwestern Electric Power Co [Member] | Ash Pond [Member]
Asset Retirement Obligations (ARO)
Revisions in Cash Flow Estimates		$ (18.0)
Dolet Hills Generating Station (Unit No. 1) [Member] | Public Utilities, Inventory, Lignite [Member]
Jointly-owned Electric Facilities
Percent of Ownership	[8]	40.20%		40.20%
Utility Plant in Service	[8]	$ 0.0		$ 342.4
Construction Work in Progress	[8]	0.0		4.6
Accumulated Depreciation	[8]	$ 0.0		$ 295.4
Dolet Hills Generating Station (Unit No. 1) [Member] | Southwestern Electric Power Co [Member] | Public Utilities, Inventory, Lignite [Member]
Jointly-owned Electric Facilities
Percent of Ownership	[8]	40.20%		40.20%
Utility Plant in Service	[8]	$ 0.0		$ 342.4
Construction Work in Progress	[8]	0.0		4.6
Accumulated Depreciation	[8]	$ 0.0		$ 295.4
Flint Creek Generating Station (Unit No. 1) [Member] | Coal [Member]
Jointly-owned Electric Facilities
Percent of Ownership	[9]	50.00%		50.00%
Utility Plant in Service	[9]	$ 377.6		$ 377.2
Construction Work in Progress	[9]	6.3		3.0
Accumulated Depreciation	[9]	$ 133.5		$ 116.0
Flint Creek Generating Station (Unit No. 1) [Member] | Southwestern Electric Power Co [Member] | Coal [Member]
Jointly-owned Electric Facilities
Percent of Ownership	[9]	50.00%		50.00%
Utility Plant in Service	[9]	$ 377.6		$ 377.2
Construction Work in Progress	[9]	6.3		3.0
Accumulated Depreciation	[9]	$ 133.5		$ 116.0
Pirkey Generating Station (Unit No. 1) [Member] | Public Utilities, Inventory, Lignite [Member]
Jointly-owned Electric Facilities
Percent of Ownership	[9]	85.90%		85.90%
Utility Plant in Service	[9]	$ 613.8		$ 602.8
Construction Work in Progress	[9]	0.0		3.7
Accumulated Depreciation	[9]	$ 528.3		$ 441.0
Pirkey Generating Station (Unit No. 1) [Member] | Southwestern Electric Power Co [Member] | Public Utilities, Inventory, Lignite [Member]
Jointly-owned Electric Facilities
Percent of Ownership	[9]	85.90%		85.90%
Utility Plant in Service	[9]	$ 613.8		$ 602.8
Construction Work in Progress	[9]	0.0		3.7
Accumulated Depreciation	[9]	$ 528.3		$ 441.0
Turk Generating Plant [Member] | Coal [Member]
Jointly-owned Electric Facilities
Percent of Ownership	[9]	73.30%		73.30%
Utility Plant in Service	[9]	$ 1,598.0		$ 1,594.3
Construction Work in Progress	[9]	10.2		2.8
Accumulated Depreciation	[9]	$ 285.6		$ 257.3
Turk Generating Plant [Member] | Southwestern Electric Power Co [Member] | Coal [Member]
Jointly-owned Electric Facilities
Percent of Ownership	[9]	73.30%		73.30%
Utility Plant in Service	[9]	$ 1,598.0		$ 1,594.3
Construction Work in Progress	[9]	10.2		2.8
Accumulated Depreciation	[9]	$ 285.6		$ 257.3
Rockport Generating Plant (Unit No. 1) [Member] | Indiana Michigan Power Co [Member]
Jointly-owned Electric Facilities
Percent of Ownership		50.00%
Rockport Generating Plant (Unit No. 1) [Member] | Indiana Michigan Power Co [Member] | Coal [Member]
Jointly-owned Electric Facilities
Percent of Ownership	[10],[11],[12]	50.00%		50.00%
Utility Plant in Service	[10],[11],[12]	$ 1,247.2		$ 1,228.5
Construction Work in Progress	[10],[11],[12]	13.9		19.6
Accumulated Depreciation	[10],[11],[12]	$ 794.5		677.3
Rockport Generating Plant (Unit No. 1) [Member] | AEP Generating Co [Member]
Jointly-owned Electric Facilities
Percent of Ownership		50.00%
Rockport Generating Plant (Unit No. 2) [Member] | AEP Generating Co [Member]
Jointly-owned Electric Facilities
Percentage Interest in Lease		50.00%
NCWF [Member] | Public Service Co Of Oklahoma [Member]
Jointly-owned Electric Facilities
Percent of Ownership		45.50%
NCWF [Member] | Public Service Co Of Oklahoma [Member] | Wind [Member]
Jointly-owned Electric Facilities
Percent of Ownership	[13],[14]	45.50%
Utility Plant in Service	[13],[14]	$ 313.7
Construction Work in Progress	[13],[14]	0.0
Accumulated Depreciation	[13],[14]	$ 4.2
NCWF [Member] | Southwestern Electric Power Co [Member]
Jointly-owned Electric Facilities
Percent of Ownership		54.50%
NCWF [Member] | Southwestern Electric Power Co [Member] | Wind [Member]
Jointly-owned Electric Facilities
Percent of Ownership	[13],[14]	54.50%
Utility Plant in Service	[13],[14]	$ 376.2
Construction Work in Progress	[13],[14]	0.0
Accumulated Depreciation	[13],[14]	5.4
Regulated Operation [Member]
Depreciation, Depletion and Amortization
Property, Plant and Equipment, Generation	[15]	21,196.8		21,587.8
Property, Plant and Equipment, Transmission		29,866.0		27,841.5
Property, Plant and Equipment, Distribution		24,440.0		23,972.1
Property, Plant and Equipment, Other		5,249.8		4,852.4
Property, Plant and Equipment, Construction Work in Progress	[15]	3,632.4		3,815.0
Accumulated Depreciation		20,375.5		20,094.2
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		$ 64,009.5		$ 61,974.6
Regulated Operation [Member] | Maximum [Member]
Depreciation, Depletion and Amortization
Depreciable Life Ranges - Generation		132 years		132 years		132 years
Depreciable Life Ranges - Transmission		75 years		75 years		81 years
Depreciable Life Ranges - Distribution		80 years		78 years		78 years
Depreciable Life Ranges - Other		75 years		75 years		75 years
Regulated Operation [Member] | Minimum [Member]
Depreciation, Depletion and Amortization
Depreciable Life Ranges - Generation		20 years		20 years		20 years
Depreciable Life Ranges - Transmission		15 years		15 years		15 years
Depreciable Life Ranges - Distribution		7 years		7 years		7 years
Depreciable Life Ranges - Other		5 years		5 years		5 years
Regulated Operation [Member] | Generation [Member] | Maximum [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate		7.80%		6.30%		5.50%
Regulated Operation [Member] | Generation [Member] | Minimum [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate		2.70%		2.70%		2.50%
Regulated Operation [Member] | Transmission [Member] | Maximum [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate		2.60%		2.60%		2.60%
Regulated Operation [Member] | Transmission [Member] | Minimum [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate		2.00%		2.00%		1.80%
Regulated Operation [Member] | Distribution [Member] | Maximum [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate		3.60%		3.70%		3.70%
Regulated Operation [Member] | Distribution [Member] | Minimum [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate		2.80%		2.70%		2.70%
Regulated Operation [Member] | Other Property Class [Member] | Maximum [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate		12.50%		11.30%		9.50%
Regulated Operation [Member] | Other Property Class [Member] | Minimum [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate		3.00%		2.80%		2.60%
Regulated Operation [Member] | AEP Texas Inc. [Member]
Depreciation, Depletion and Amortization
Property, Plant and Equipment, Generation		$ 0.0		$ 0.0
Property, Plant and Equipment, Transmission		5,849.9		5,279.6
Property, Plant and Equipment, Distribution		4,917.2		4,580.8
Property, Plant and Equipment, Other		958.7		866.0
Property, Plant and Equipment, Construction Work in Progress		551.3		614.1
Accumulated Depreciation		1,642.9		1,528.1
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		$ 10,634.2		$ 9,812.4
Regulated Operation [Member] | AEP Texas Inc. [Member] | Maximum [Member]
Depreciation, Depletion and Amortization
Depreciable Life Ranges - Transmission		75 years		75 years		81 years
Depreciable Life Ranges - Distribution		70 years		70 years		70 years
Depreciable Life Ranges - Other		50 years		50 years		50 years
Regulated Operation [Member] | AEP Texas Inc. [Member] | Minimum [Member]
Depreciation, Depletion and Amortization
Depreciable Life Ranges - Transmission		50 years		50 years		45 years
Depreciable Life Ranges - Distribution		7 years		7 years		7 years
Depreciable Life Ranges - Other		5 years		5 years		5 years
Regulated Operation [Member] | AEP Texas Inc. [Member] | Transmission [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate		2.20%		2.00%		1.80%
Regulated Operation [Member] | AEP Texas Inc. [Member] | Distribution [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate		2.90%		3.10%		3.50%
Regulated Operation [Member] | AEP Texas Inc. [Member] | Other Property Class [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate		5.80%		6.10%		6.30%
Regulated Operation [Member] | AEP Transmission Co [Member]
Depreciation, Depletion and Amortization
Property, Plant and Equipment, Generation		$ 0.0		$ 0.0
Property, Plant and Equipment, Transmission		10,886.3		9,593.5
Property, Plant and Equipment, Distribution		0.0		0.0
Property, Plant and Equipment, Other		427.2		328.8
Property, Plant and Equipment, Construction Work in Progress		1,394.8		1,422.6
Accumulated Depreciation		772.9		572.8
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		$ 11,935.4		$ 10,772.1
Regulated Operation [Member] | AEP Transmission Co [Member] | Maximum [Member]
Depreciation, Depletion and Amortization
Depreciable Life Ranges - Transmission		75 years		75 years		75 years
Depreciable Life Ranges - Other		56 years		64 years		64 years
Regulated Operation [Member] | AEP Transmission Co [Member] | Minimum [Member]
Depreciation, Depletion and Amortization
Depreciable Life Ranges - Transmission		24 years		24 years		24 years
Depreciable Life Ranges - Other		5 years		5 years		5 years
Regulated Operation [Member] | AEP Transmission Co [Member] | Transmission [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate		2.50%		2.40%		2.00%
Regulated Operation [Member] | AEP Transmission Co [Member] | Other Property Class [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate		6.70%		6.30%		5.80%
Regulated Operation [Member] | Appalachian Power Co [Member]
Depreciation, Depletion and Amortization
Property, Plant and Equipment, Generation		$ 6,683.9		$ 6,633.7
Property, Plant and Equipment, Transmission		4,322.4		3,900.5
Property, Plant and Equipment, Distribution		4,683.3		4,464.3
Property, Plant and Equipment, Other		668.9		598.0
Property, Plant and Equipment, Construction Work in Progress		469.9		484.6
Accumulated Depreciation		5,047.4		4,711.0
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		$ 11,781.0		$ 11,370.1
Regulated Operation [Member] | Appalachian Power Co [Member] | Maximum [Member]
Depreciation, Depletion and Amortization
Depreciable Life Ranges - Generation		118 years		118 years		118 years
Depreciable Life Ranges - Transmission		75 years		75 years		71 years
Depreciable Life Ranges - Distribution		57 years		57 years		57 years
Depreciable Life Ranges - Other		55 years		55 years		55 years
Regulated Operation [Member] | Appalachian Power Co [Member] | Minimum [Member]
Depreciation, Depletion and Amortization
Depreciable Life Ranges - Generation		35 years		35 years		35 years
Depreciable Life Ranges - Transmission		15 years		15 years		15 years
Depreciable Life Ranges - Distribution		12 years		12 years		12 years
Depreciable Life Ranges - Other		5 years		5 years		5 years
Regulated Operation [Member] | Appalachian Power Co [Member] | Generation [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate		3.60%		3.30%		3.20%
Regulated Operation [Member] | Appalachian Power Co [Member] | Transmission [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate		2.10%		2.20%		1.80%
Regulated Operation [Member] | Appalachian Power Co [Member] | Distribution [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate		3.50%		3.70%		3.70%
Regulated Operation [Member] | Appalachian Power Co [Member] | Other Property Class [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate		8.50%		7.80%		7.20%
Regulated Operation [Member] | Indiana Michigan Power Co [Member]
Depreciation, Depletion and Amortization
Property, Plant and Equipment, Generation		$ 5,531.8		$ 5,264.7
Property, Plant and Equipment, Transmission		1,783.1		1,696.4
Property, Plant and Equipment, Distribution		2,800.1		2,594.6
Property, Plant and Equipment, Other		755.1		644.6
Property, Plant and Equipment, Construction Work in Progress		302.8		362.4
Accumulated Depreciation		3,885.3		3,538.6
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		$ 7,287.6		$ 7,024.1
Regulated Operation [Member] | Indiana Michigan Power Co [Member] | Maximum [Member]
Depreciation, Depletion and Amortization
Depreciable Life Ranges - Generation		132 years		132 years		132 years
Depreciable Life Ranges - Transmission		70 years		70 years		73 years
Depreciable Life Ranges - Distribution		71 years		71 years		75 years
Depreciable Life Ranges - Other		51 years		51 years		50 years
Regulated Operation [Member] | Indiana Michigan Power Co [Member] | Minimum [Member]
Depreciation, Depletion and Amortization
Depreciable Life Ranges - Generation		20 years		20 years		20 years
Depreciable Life Ranges - Transmission		45 years		45 years		50 years
Depreciable Life Ranges - Distribution		14 years		14 years		9 years
Depreciable Life Ranges - Other		5 years		5 years		5 years
Regulated Operation [Member] | Indiana Michigan Power Co [Member] | Generation [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate		4.70%		4.60%		4.00%
Regulated Operation [Member] | Indiana Michigan Power Co [Member] | Transmission [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate		2.40%		2.30%		1.90%
Regulated Operation [Member] | Indiana Michigan Power Co [Member] | Distribution [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate		3.40%		3.40%		3.40%
Regulated Operation [Member] | Indiana Michigan Power Co [Member] | Other Property Class [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate		9.00%		10.20%		9.40%
Regulated Operation [Member] | Ohio Power Co [Member]
Depreciation, Depletion and Amortization
Property, Plant and Equipment, Generation		$ 0.0		$ 0.0
Property, Plant and Equipment, Transmission		2,992.8		2,831.9
Property, Plant and Equipment, Distribution		6,070.6		5,708.3
Property, Plant and Equipment, Other		982.2		888.5
Property, Plant and Equipment, Construction Work in Progress		365.0		362.3
Accumulated Depreciation		2,457.4		2,348.8
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		$ 7,953.2		$ 7,442.2
Regulated Operation [Member] | Ohio Power Co [Member] | Maximum [Member]
Depreciation, Depletion and Amortization
Depreciable Life Ranges - Transmission		60 years		60 years		60 years
Depreciable Life Ranges - Distribution		70 years		65 years		65 years
Depreciable Life Ranges - Other		50 years		50 years		50 years
Regulated Operation [Member] | Ohio Power Co [Member] | Minimum [Member]
Depreciation, Depletion and Amortization
Depreciable Life Ranges - Transmission		39 years		39 years		39 years
Depreciable Life Ranges - Distribution		11 years		14 years		14 years
Depreciable Life Ranges - Other		5 years		5 years		5 years
Regulated Operation [Member] | Ohio Power Co [Member] | Transmission [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate		2.30%		2.30%		2.30%
Regulated Operation [Member] | Ohio Power Co [Member] | Distribution [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate		2.90%		3.10%		3.10%
Regulated Operation [Member] | Ohio Power Co [Member] | Other Property Class [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate		6.10%		5.00%		4.90%
Regulated Operation [Member] | Public Service Co Of Oklahoma [Member]
Depreciation, Depletion and Amortization
Property, Plant and Equipment, Generation		$ 1,802.4		$ 1,480.7
Property, Plant and Equipment, Transmission		1,107.7		1,069.9
Property, Plant and Equipment, Distribution		3,004.9		2,853.0
Property, Plant and Equipment, Other		433.5		388.1
Property, Plant and Equipment, Construction Work in Progress		156.0		128.7
Accumulated Depreciation		1,707.0		1,607.3
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		$ 4,797.5		$ 4,313.1
Regulated Operation [Member] | Public Service Co Of Oklahoma [Member] | Maximum [Member]
Depreciation, Depletion and Amortization
Depreciable Life Ranges - Generation		75 years		75 years		75 years
Depreciable Life Ranges - Transmission		75 years		75 years		75 years
Depreciable Life Ranges - Distribution		78 years		78 years		78 years
Depreciable Life Ranges - Other		56 years		64 years		64 years
Regulated Operation [Member] | Public Service Co Of Oklahoma [Member] | Minimum [Member]
Depreciation, Depletion and Amortization
Depreciable Life Ranges - Generation		30 years		35 years		35 years
Depreciable Life Ranges - Transmission		42 years		45 years		45 years
Depreciable Life Ranges - Distribution		15 years		15 years		15 years
Depreciable Life Ranges - Other		5 years		5 years		5 years
Regulated Operation [Member] | Public Service Co Of Oklahoma [Member] | Generation [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate		2.80%		3.10%		2.90%
Regulated Operation [Member] | Public Service Co Of Oklahoma [Member] | Transmission [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate		2.40%		2.20%		2.40%
Regulated Operation [Member] | Public Service Co Of Oklahoma [Member] | Distribution [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate		2.90%		2.90%		2.90%
Regulated Operation [Member] | Public Service Co Of Oklahoma [Member] | Other Property Class [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate		6.10%		5.70%		5.60%
Regulated Operation [Member] | Southwestern Electric Power Co [Member]
Depreciation, Depletion and Amortization
Property, Plant and Equipment, Generation	[15]	$ 4,734.5		$ 4,681.4
Property, Plant and Equipment, Transmission		2,316.9		2,165.7
Property, Plant and Equipment, Distribution		2,514.3		2,382.5
Property, Plant and Equipment, Other		542.0		564.5
Property, Plant and Equipment, Construction Work in Progress	[15]	240.7		228.3
Accumulated Depreciation		3,002.2		3,032.0
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		$ 7,346.2		$ 6,990.4
Regulated Operation [Member] | Southwestern Electric Power Co [Member] | Maximum [Member]
Depreciation, Depletion and Amortization
Depreciable Life Ranges - Generation		65 years		65 years		70 years
Depreciable Life Ranges - Transmission		74 years		73 years		73 years
Depreciable Life Ranges - Distribution		80 years		67 years		70 years
Depreciable Life Ranges - Other		58 years		52 years		55 years
Regulated Operation [Member] | Southwestern Electric Power Co [Member] | Minimum [Member]
Depreciation, Depletion and Amortization
Depreciable Life Ranges - Generation		30 years		35 years		40 years
Depreciable Life Ranges - Transmission		49 years		47 years		50 years
Depreciable Life Ranges - Distribution		15 years		15 years		25 years
Depreciable Life Ranges - Other		5 years		5 years		5 years
Regulated Operation [Member] | Southwestern Electric Power Co [Member] | Generation [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate		2.70%		2.70%		2.50%
Regulated Operation [Member] | Southwestern Electric Power Co [Member] | Transmission [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate		2.40%		2.30%		2.40%
Regulated Operation [Member] | Southwestern Electric Power Co [Member] | Distribution [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate		2.80%		2.70%		2.70%
Regulated Operation [Member] | Southwestern Electric Power Co [Member] | Other Property Class [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate		8.60%		8.50%		7.60%
Unregulated Operation [Member]
Depreciation, Depletion and Amortization
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		$ 1,991.8		$ 1,927.0
Depreciable Life Ranges - Distribution						40 years
Unregulated Operation [Member] | Maximum [Member]
Depreciation, Depletion and Amortization
Depreciable Life Ranges - Generation		59 years		59 years		59 years
Depreciable Life Ranges - Transmission		40 years		40 years		40 years
Depreciable Life Ranges - Other		35 years	[16]	50 years		50 years
Unregulated Operation [Member] | Minimum [Member]
Depreciation, Depletion and Amortization
Depreciable Life Ranges - Generation		10 years		15 years		15 years
Depreciable Life Ranges - Transmission		30 years		30 years		30 years
Depreciable Life Ranges - Other		5 years	[16]	5 years		5 years
Unregulated Operation [Member] | Generation [Member] | Maximum [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate		10.40%		4.00%		21.20%
Unregulated Operation [Member] | Generation [Member] | Minimum [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate		3.80%		3.60%		3.20%
Unregulated Operation [Member] | Transmission [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate		2.60%		2.50%		2.50%
Unregulated Operation [Member] | Distribution [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate						2.30%
Unregulated Operation [Member] | Other Property Class [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate		16.50%		16.10%		17.60%
Unregulated Operation [Member] | AEP Texas Inc. [Member]
Depreciation, Depletion and Amortization
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		$ 1.2		$ 1.2
Unregulated Operation [Member] | AEP Transmission Co [Member]
Depreciation, Depletion and Amortization
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		0.3		0.7
Unregulated Operation [Member] | Appalachian Power Co [Member]
Depreciation, Depletion and Amortization
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		23.3		24.0
Unregulated Operation [Member] | Indiana Michigan Power Co [Member]
Depreciation, Depletion and Amortization
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		23.3		28.2
Unregulated Operation [Member] | Ohio Power Co [Member]
Depreciation, Depletion and Amortization
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		9.8		9.9
Unregulated Operation [Member] | Public Service Co Of Oklahoma [Member]
Depreciation, Depletion and Amortization
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		5.3		6.9
Unregulated Operation [Member] | Southwestern Electric Power Co [Member]
Depreciation, Depletion and Amortization
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		53.9		97.8
Oklaunion Generating Station [Member] | AEP Texas Inc. [Member]
Asset Retirement Obligations (ARO)
Revisions in Cash Flow Estimates		(17.0)
Oklaunion Generating Station [Member] | Public Service Co Of Oklahoma [Member]
Asset Retirement Obligations (ARO)
Revisions in Cash Flow Estimates		(5.0)
Dolet Hills Power Station [Member] | Southwestern Electric Power Co [Member]
Asset Retirement Obligations (ARO)
Revisions in Cash Flow Estimates		21.0
Jointly-owned Electric Facilities
Asset Impairments and Other Related Charges		12.0
Glen Lyn Station [Member] | Appalachian Power Co [Member]
Asset Retirement Obligations (ARO)
Revisions in Cash Flow Estimates		79.0		199.0
Cook Nuclear Plant [Member] | Indiana Michigan Power Co [Member]
Asset Retirement Obligations (ARO)
Revisions in Cash Flow Estimates		58.0
Generation and Marketing [Member]
Depreciation, Depletion and Amortization
Accumulated Depreciation		241.0		166.1
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		1,864.4		$ 1,744.1
Jointly-owned Electric Facilities
Asset Impairments and Other Related Charges		0.0				$ 31.0
Generation and Marketing [Member] | Conesville Generating Station [Member]
Asset Retirement Obligations (ARO)
Liabilities Settled		$ (106.0)

[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] Includes $18 million of ARO classified as Liabilities Held for Sale on the balance sheet. See “Disposition of KPCo and KTCo” section of Note 7 for additional information.

[3] Includes ARO related to Sabine and DHLC.

[4] Includes ARO related to asbestos removal.

[5] Includes ARO related to ash disposal facilities.

[6] Includes ARO related to nuclear decommissioning costs for the Cook Plant of $1.93 billion and $1.80 billion as of December 31, 2021 and 2020, respectively.

[7] Unless discussed above, primarily related to ash ponds, landfills and mine reclamation, generally due to changes in estimated closure area, volumes and/or unit costs.

[8] Operated by CLECO, a nonaffiliated company. The Dolet Hills Power Station was retired in December 2021.

[9] Operated by SWEPCo.

[10] AEGCo owns 50% of Unit 1 with I&M and 50% of capital additions for Unit 2.

[11] Amounts include I&M’s 50% ownership of both Unit 1 and capital additions for Unit 2. Unit 2 is subject to a finance lease with a nonaffiliated company. See the “Rockport Lease” section of Note 13 for additional information.

[12] Operated by I&M.

[13] Operated by PSO.

[14] PSO and SWEPCo own undivided interests of 45.5% and 54.5% of the NCWF, respectively. Sundance was placed into service in April 2021. Maverick was placed into service in September 2021. See the “Acquisitions” section of Note 7 for additional information.

[15] AEP and SWEPCo’s regulated generation and regulated CWIP include amounts related to SWEPCo’s Arkansas jurisdictional share of the Turk Plant.

[16] In 2020 management announced plans to retire the Pirkey Plant in 2023 and the related depreciable lives have been adjusted accordingly. See Note 5 - Effects of Regulation for additional information.