Consolidated Statements of Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020		Dec. 31, 2019		Dec. 31, 2018
Revenues
Revenue from Contracts with Customers	$ 14,918.5		$ 15,561.4		$ 16,195.7
Sales to AEP Affiliates	0.0		0.0		0.0
TOTAL REVENUES	14,918.5		15,561.4		16,195.7
Expenses
Other Operation	2,572.4		2,743.7		2,979.2
Maintenance	1,010.4		1,213.9		1,247.4
Asset Impairments and Other Related Charges	0.0		156.4		70.6
Depreciation and Amortization	2,682.8		2,514.5		2,286.6
Taxes Other Than Income Taxes	1,295.5		1,234.5		1,142.7
TOTAL EXPENSES	11,930.8		12,969.1		13,513.0
OPERATING INCOME (LOSS)	2,987.7		2,592.3		2,682.7
Other Income (Expense):
Other Income	57.0		26.6		18.2
Allowance for Equity Funds Used During Construction	148.1		168.4		132.5
Non-Service Cost Components of Net Periodic Benefit Cost	119.0		120.0		124.5
Interest Expense	(1,165.7)		(1,072.5)		(984.4)
INCOME BEFORE INCOME TAX EXPENSE (BENEFIT) AND EQUITY EARNINGS (LOSS)	2,146.1		1,834.8		1,973.5
Income Tax Expense (Benefit)	40.5		(12.9)		115.3
Equity Earnings (Loss) of Unconsolidated Subsidiaries	91.1		72.1		73.1
Net Income (Loss)	2,196.7		1,919.8		1,931.3
Net Income Attributable to Noncontrolling Interests	(3.4)		(1.3)		7.5
EARNINGS ATTRIBUTABLE TO COMMON SHAREHOLDERS	$ 2,200.1		$ 1,921.1		$ 1,923.8
Earnings Per Share
WEIGHTED AVERAGE NUMBER OF BASIC AEP COMMON SHARES OUTSTANDING	495,718,223		493,694,345		492,774,600
Total Basic Earnings (Loss) per Share Attributable to AEP Common Shareholders	$ 4.44		$ 3.89		$ 3.90
WEIGHTED AVERAGE NUMBER OF DILUTED AEP COMMON SHARES OUTSTANDING	497,226,867		495,306,238		493,758,277
TOTAL DILUTED EARNINGS PER SHARE ATTRIBUTABLE TO AEP COMMON SHAREHOLDERS	$ 4.42		$ 3.88		$ 3.90
Vertically Integrated Utilities [Member]
Revenues
Revenue from Contracts with Customers	$ 8,753.2		$ 9,245.7		$ 9,556.7
Transmission and Distribution Utilities [Member]
Revenues
Revenue from Contracts with Customers	4,238.7		4,319.0		4,552.3
Generation and Marketing Revenues [Member]
Revenues
Revenue from Contracts with Customers	1,621.0		1,721.8		1,818.1
Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	305.6		274.9		268.6
TOTAL REVENUES	61.5	[1]	61.7	[2]	25.0	[3]
Fuel and Other Consumables Used for Electric Generation [Member]
Expenses
Cost of Goods and Services Sold	1,439.3		1,940.9		2,359.4
Purchased Electricity for Resale [Member]
Expenses
Cost of Goods and Services Sold	2,930.4		3,165.2		3,427.1
AEP Texas Inc. [Member]
Revenues
Revenue from Contracts with Customers	1,528.0		1,551.6		1,493.0
Sales to AEP Affiliates	90.8		160.5		105.2
TOTAL REVENUES	1,618.9		1,709.3		1,595.3
Expenses
Other Operation	488.9		492.0		488.9
Maintenance	80.5		158.8		89.4
Asset Impairments and Other Related Charges	0.0		32.5		0.0
Depreciation and Amortization	529.8		622.3		499.6
Taxes Other Than Income Taxes	136.4		140.6		132.6
TOTAL EXPENSES	1,249.3		1,477.3		1,249.0
OPERATING INCOME (LOSS)	369.6		232.0		346.3
Other Income (Expense):
Interest Income	1.4		3.4		0.8
Allowance for Equity Funds Used During Construction	19.4		15.2		20.0
Non-Service Cost Components of Net Periodic Benefit Cost	11.2		11.3		12.3
Interest Expense	(171.8)		(137.2)		(147.3)
INCOME BEFORE INCOME TAX EXPENSE (BENEFIT) AND EQUITY EARNINGS (LOSS)	229.8		124.7		232.1
Income Tax Expense (Benefit)	(11.2)		(53.6)		20.8
Net Income (Loss)	241.0		178.3		211.3
AEP Texas Inc. [Member] | Transmission and Distribution Utilities [Member]
Revenues
Revenue from Contracts with Customers	1,524.9		1,545.9		1,486.3
AEP Texas Inc. [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	3.2		2.9		3.8
TOTAL REVENUES	87.5	[4]	157.1	[5]	103.6	[6]
AEP Texas Inc. [Member] | Fuel and Other Consumables Used for Electric Generation [Member]
Expenses
Cost of Goods and Services Sold	13.7		31.1		38.5
AEP Transmission Co [Member]
Revenues
Revenue from Contracts with Customers	1,232.7		1,042.1		832.0
Sales to AEP Affiliates	896.3		806.7		598.9
TOTAL REVENUES	1,145.7		1,021.4		776.1
Expenses
Other Operation	99.8		93.9		83.8
Maintenance	10.2		15.4		10.5
Depreciation and Amortization	249.0		176.0		133.9
Taxes Other Than Income Taxes	205.2		168.9		137.8
TOTAL EXPENSES	564.2		454.2		366.0
OPERATING INCOME (LOSS)	581.5		567.2		410.1
Other Income (Expense):
Interest Income	2.4		3.0		2.5
Allowance for Equity Funds Used During Construction	74.0		84.3		70.6
Interest Expense	(127.8)		(97.4)		(83.2)
INCOME BEFORE INCOME TAX EXPENSE (BENEFIT) AND EQUITY EARNINGS (LOSS)	530.1		557.1		400.0
Income Tax Expense (Benefit)	106.7		117.4		84.1
Net Income (Loss)	423.4		439.7		315.9
AEP Transmission Co [Member] | Transmission [Member]
Revenues
Revenue from Contracts with Customers	248.8		214.6		177.0
AEP Transmission Co [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	0.6		0.1		0.2
TOTAL REVENUES	0.0	[4]	0.0	[5]	0.0	[6]
Appalachian Power Co [Member]
Revenues
Revenue from Contracts with Customers	2,809.2		2,911.1		2,993.2
Sales to AEP Affiliates	174.7		205.3		181.4
TOTAL REVENUES	2,796.2		2,924.7		2,967.5
Expenses
Other Operation	530.5		567.6		511.6
Maintenance	226.8		255.4		316.9
Asset Impairments and Other Related Charges	0.0		92.9		0.0
Re-Establishment of Regulatory Asset - Coal Fired Generation	(49.0)		0.0		0.0
Depreciation and Amortization	507.5		466.8		428.4
Taxes Other Than Income Taxes	150.2		146.2		134.7
TOTAL EXPENSES	2,239.6		2,527.4		2,484.0
OPERATING INCOME (LOSS)	556.6		397.3		483.5
Other Income (Expense):
Interest Income	1.6		2.4		1.8
Carrying Costs Income	0.0		0.0		1.3
Allowance for Equity Funds Used During Construction	14.6		16.6		13.2
Non-Service Cost Components of Net Periodic Benefit Cost	18.8		17.0		17.9
Interest Expense	(217.6)		(205.0)		(194.8)
INCOME BEFORE INCOME TAX EXPENSE (BENEFIT) AND EQUITY EARNINGS (LOSS)	374.0		228.3		322.9
Income Tax Expense (Benefit)	4.3		(78.0)		(44.9)
Net Income (Loss)	369.7		306.3		367.8
Appalachian Power Co [Member] | Vertically Integrated Utilities [Member]
Revenues
Revenue from Contracts with Customers	2,610.9		2,708.2		2,777.1
Appalachian Power Co [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	10.6		11.2		9.0
TOTAL REVENUES	0.0	[4]	0.0	[5]	(1.9)	[6]
Appalachian Power Co [Member] | Fuel and Other Consumables Used for Electric Generation [Member]
Expenses
Cost of Goods and Services Sold	513.3		607.5		588.9
Appalachian Power Co [Member] | Purchased Electricity for Resale [Member]
Expenses
Cost of Goods and Services Sold	360.3		391.0		503.5
Indiana Michigan Power Co [Member]
Revenues
Revenue from Contracts with Customers	2,236.0		2,308.1		2,381.0
Sales to AEP Affiliates	10.5		10.5		22.1
Other Revenues - Affiliated	60.8		63.4		63.4
TOTAL REVENUES	2,241.8		2,306.7		2,370.7
Expenses
Purchased Electricity from AEP Affiliates	172.8		214.9		237.9
Other Operation	650.0		641.2		585.4
Maintenance	193.2		231.2		238.1
Depreciation and Amortization	411.6		350.6		293.1
Taxes Other Than Income Taxes	107.1		105.1		98.9
TOTAL EXPENSES	1,878.9		1,965.9		1,993.5
OPERATING INCOME (LOSS)	362.9		340.8		377.2
Other Income (Expense):
Other Income	10.0		18.2		19.2
Allowance for Equity Funds Used During Construction	11.5		19.4		11.9
Non-Service Cost Components of Net Periodic Benefit Cost	16.7		17.7		18.1
Interest Expense	(112.3)		(117.9)		(124.1)
INCOME BEFORE INCOME TAX EXPENSE (BENEFIT) AND EQUITY EARNINGS (LOSS)	277.3		258.8		290.4
Income Tax Expense (Benefit)	(7.5)		(10.6)		29.1
Net Income (Loss)	284.8		269.4		261.3
Indiana Michigan Power Co [Member] | Vertically Integrated Utilities [Member]
Revenues
Revenue from Contracts with Customers	2,165.3		2,222.1		2,272.6
Indiana Michigan Power Co [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	5.2		10.7		12.6
Sales to AEP Affiliates	69.0		73.0		70.0
TOTAL REVENUES	0.0	[4]	0.0	[5]	(8.2)	[6]
Indiana Michigan Power Co [Member] | Fuel and Other Consumables Used for Electric Generation [Member]
Expenses
Cost of Goods and Services Sold	162.0		190.6		318.3
Indiana Michigan Power Co [Member] | Purchased Electricity for Resale [Member]
Expenses
Cost of Goods and Services Sold	182.2		232.3		221.8
Ohio Power Co [Member]
Revenues
Revenue from Contracts with Customers	2,665.0		2,748.8		3,079.9
Sales to AEP Affiliates	41.5		27.3		21.0
TOTAL REVENUES	2,749.1		2,797.6		3,063.4
Expenses
Purchased Electricity from AEP Affiliates	119.7		156.0		135.3
Amortization of Generation Deferrals	0.0		65.3		223.9
Other Operation	822.6		742.6		771.3
Maintenance	127.1		150.1		156.0
Depreciation and Amortization	276.6		240.9		259.7
Taxes Other Than Income Taxes	450.2		434.2		412.8
TOTAL EXPENSES	2,345.4		2,396.4		2,643.6
OPERATING INCOME (LOSS)	403.7		401.2		419.8
Other Income (Expense):
Interest Income	1.0		3.2		3.4
Carrying Costs Income	1.6		1.0		1.7
Allowance for Equity Funds Used During Construction	12.5		18.2		9.8
Non-Service Cost Components of Net Periodic Benefit Cost	15.0		14.6		15.5
Interest Expense	(117.2)		(106.2)		(100.7)
INCOME BEFORE INCOME TAX EXPENSE (BENEFIT) AND EQUITY EARNINGS (LOSS)	316.6		332.0		349.5
Income Tax Expense (Benefit)	45.2		34.9		24.0
Net Income (Loss)	271.4		297.1		325.5
Ohio Power Co [Member] | Transmission and Distribution Utilities [Member]
Revenues
Revenue from Contracts with Customers	2,698.6		2,759.5		3,033.8
Ohio Power Co [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	9.0		10.8		8.6
TOTAL REVENUES	17.5	[4]	17.1	[5]	4.3	[6]
Ohio Power Co [Member] | Purchased Electricity for Resale [Member]
Expenses
Cost of Goods and Services Sold	549.2		607.3		684.6
Public Service Co Of Oklahoma [Member]
Revenues
Revenue from Contracts with Customers	1,263.9		1,512.8		1,536.4
Sales to AEP Affiliates	5.2		6.1		5.4
TOTAL REVENUES	1,266.1		1,481.8		1,547.3
Expenses
Other Operation	327.3		315.0		372.8
Maintenance	98.4		100.7		104.8
Depreciation and Amortization	173.5		169.5		164.0
Taxes Other Than Income Taxes	47.5		43.3		42.8
TOTAL EXPENSES	1,090.2		1,282.5		1,404.8
OPERATING INCOME (LOSS)	175.9		199.3		142.5
Other Income (Expense):
Interest Income	0.1		1.2		0.1
Allowance for Equity Funds Used During Construction	4.0		2.7		0.4
Non-Service Cost Components of Net Periodic Benefit Cost	8.5		8.4		8.7
Interest Expense	(60.3)		(66.5)		(63.5)
INCOME BEFORE INCOME TAX EXPENSE (BENEFIT) AND EQUITY EARNINGS (LOSS)	128.2		145.1		88.2
Income Tax Expense (Benefit)	5.2		7.5		5.0
Net Income (Loss)	123.0		137.6		83.2
Public Service Co Of Oklahoma [Member] | Vertically Integrated Utilities [Member]
Revenues
Revenue from Contracts with Customers	1,246.1		1,469.6		1,537.6
Public Service Co Of Oklahoma [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	14.8		6.1		4.3
TOTAL REVENUES	0.0	[4]	0.0	[5]	0.0	[6]
Public Service Co Of Oklahoma [Member] | Fuel and Other Consumables Used for Electric Generation [Member]
Expenses
Cost of Goods and Services Sold	15.6		195.1		240.5
Public Service Co Of Oklahoma [Member] | Purchased Electricity for Resale [Member]
Expenses
Cost of Goods and Services Sold	427.9		458.9		479.9
Southwestern Electric Power Co [Member]
Revenues
Revenue from Contracts with Customers	1,735.3		1,799.2		1,817.0
Sales to AEP Affiliates	41.0		36.9		35.1
Provision for Refund	(2.0)		(32.0)		(6.7)
TOTAL REVENUES	1,738.5		1,750.9		1,821.9
Expenses
Other Operation	338.3		348.0		384.2
Maintenance	129.7		145.6		141.5
Depreciation and Amortization	272.7		249.1		239.5
Taxes Other Than Income Taxes	102.8		100.2		99.6
TOTAL EXPENSES	1,448.0		1,495.2		1,544.2
OPERATING INCOME (LOSS)	290.5		255.7		277.7
Other Income (Expense):
Interest Income	2.1		2.6		5.4
Allowance for Equity Funds Used During Construction	7.7		6.8		6.0
Non-Service Cost Components of Net Periodic Benefit Cost	8.4		8.5		8.7
Interest Expense	(118.5)		(119.1)		(127.9)
INCOME BEFORE INCOME TAX EXPENSE (BENEFIT) AND EQUITY EARNINGS (LOSS)	190.2		154.5		169.9
Income Tax Expense (Benefit)	9.4		(4.7)		20.4
Equity Earnings (Loss) of Unconsolidated Subsidiaries	2.9		3.0		2.7
Net Income (Loss)	183.7		162.2		152.2
Net Income Attributable to Noncontrolling Interests	2.9		3.6		5.0
EARNINGS ATTRIBUTABLE TO COMMON SHAREHOLDERS	180.8		158.6		147.2
Southwestern Electric Power Co [Member] | Vertically Integrated Utilities [Member]
Revenues
Revenue from Contracts with Customers	1,696.6		1,744.6		1,791.9
Southwestern Electric Power Co [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	2.9		1.4		1.6
TOTAL REVENUES	0.0	[4]	0.0	[5]	0.0	[6]
Southwestern Electric Power Co [Member] | Fuel and Other Consumables Used for Electric Generation [Member]
Expenses
Cost of Goods and Services Sold	443.5		472.8		502.3
Southwestern Electric Power Co [Member] | Purchased Electricity for Resale [Member]
Expenses
Cost of Goods and Services Sold	$ 161.0		$ 179.5		$ 177.1

[1] Amounts include affiliated and nonaffiliated revenues.

[2] Amounts include affiliated and nonaffiliated revenues.

[3] Amounts include affiliated and nonaffiliated revenues.

[4] Amounts include affiliated and nonaffiliated revenues.

[5] Amounts include affiliated and nonaffiliated revenues.

[6] Amounts include affiliated and nonaffiliated revenues.