Consolidated Statements of Income - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021		Mar. 31, 2020
Revenues
Revenue from Contracts with Customers	$ 4,281.1		$ 3,747.5
Sales to AEP Affiliates	0.0		0.0
TOTAL REVENUES	4,281.1		3,747.5
Expenses
Other Operation	592.4		602.1
Maintenance	274.9		249.5
Depreciation and Amortization	696.3		672.2
Taxes Other Than Income Taxes	346.5		321.1
TOTAL EXPENSES	3,470.8		2,995.9
OPERATING INCOME (LOSS)	810.3		751.6
Other Income (Expense):
Other Income	21.7		(4.4)
Allowance for Equity Funds Used During Construction	33.4		31.4
Non-Service Cost Components of Net Periodic Benefit Cost	29.6		29.7
Interest Expense	(290.2)		(292.1)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	604.8		516.2
Income Tax Expense (Benefit)	54.5		46.5
Equity Earnings (Loss) of Unconsolidated Subsidiaries	28.5		29.6
Net Income (Loss)	578.8		499.3
Net Income (Loss) Attributable to Noncontrolling Interests	3.8		4.1
Earnings Attributable to Common Shareholders	$ 575.0		$ 495.2
Earnings Per Share
Weighted Average Number of Basic AEP Common Shares Outstanding	497,058,635		494,596,869
Total Basic Earnings Per Share Attributable to AEP Common Shareholders	$ 1.16		$ 1.00
Weighted Average Number of Diluted AEP Common Shares Outstanding	498,164,219		496,608,918
Total Diluted Earnings Per Share Attributable to AEP Common Shareholders	$ 1.15		$ 1.00
Common Stock, Dividends Per Share, Declared	$ 0.74		$ 0.70
Vertically Integrated Utilities [Member]
Revenues
Revenue from Contracts with Customers	$ 2,504.5		$ 2,193.0
Transmission and Distribution Utilities [Member]
Revenues
Revenue from Contracts with Customers	1,082.3		1,075.2
Generation and Marketing [Member]
Revenues
Revenue from Contracts with Customers	601.7		408.4
Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	92.6		70.9
TOTAL REVENUES	4.8	[1]	19.9	[2]
Purchased Electricity, Fuel and Other Consumables Used for Electric Generation [Member]
Expenses
Cost of Goods and Services Sold	1,560.7		1,151.0
AEP Texas Inc. [Member]
Revenues
Sales to AEP Affiliates	1.0		31.1
TOTAL REVENUES	364.2		423.6
Expenses
Other Operation	122.2		117.5
Maintenance	19.1		20.6
Depreciation and Amortization	97.5		162.5
Taxes Other Than Income Taxes	36.3		34.0
TOTAL EXPENSES	275.1		334.6
OPERATING INCOME (LOSS)	89.1		89.0
Other Income (Expense):
Interest Income	0.2		0.6
Allowance for Equity Funds Used During Construction	4.1		5.1
Non-Service Cost Components of Net Periodic Benefit Cost	2.8		2.8
Interest Expense	(43.0)		(42.5)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	53.2		55.0
Income Tax Expense (Benefit)	7.1		7.4
Net Income (Loss)	46.1		47.6
AEP Texas Inc. [Member] | Transmission and Distribution Utilities [Member]
Revenues
Revenue from Contracts with Customers	361.7		391.6
AEP Texas Inc. [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	1.5		0.9
TOTAL REVENUES	0.0	[3]	30.2	[4]
AEP Transmission Co [Member]
Revenues
Sales to AEP Affiliates	285.6		233.7
TOTAL REVENUES	361.7		295.6
Expenses
Other Operation	21.1		23.8
Maintenance	3.6		3.2
Depreciation and Amortization	70.6		56.0
Taxes Other Than Income Taxes	57.8		50.4
TOTAL EXPENSES	153.1		133.4
OPERATING INCOME (LOSS)	208.6		162.2
Other Income (Expense):
Interest Income	0.1		0.8
Allowance for Equity Funds Used During Construction	16.7		16.2
Interest Expense	(34.1)		(29.6)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	191.3		149.6
Income Tax Expense (Benefit)	39.6		31.8
Net Income (Loss)	151.7		117.8
AEP Transmission Co [Member] | Transmission [Member]
Revenues
Revenue from Contracts with Customers	76.0		61.3
AEP Transmission Co [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	0.1		0.6
TOTAL REVENUES	0.0	[3]	0.0	[4]
Appalachian Power Co [Member]
Revenues
Sales to AEP Affiliates	50.1		49.7
TOTAL REVENUES	817.0		749.4
Expenses
Other Operation	150.4		134.0
Maintenance	65.2		50.3
Depreciation and Amortization	135.8		122.2
Taxes Other Than Income Taxes	37.7		37.9
TOTAL EXPENSES	643.1		578.0
OPERATING INCOME (LOSS)	173.9		171.4
Other Income (Expense):
Interest Income	0.3		0.3
Allowance for Equity Funds Used During Construction	3.5		2.4
Non-Service Cost Components of Net Periodic Benefit Cost	4.7		4.7
Interest Expense	(54.9)		(53.1)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	127.5		125.7
Income Tax Expense (Benefit)	5.0		10.4
Net Income (Loss)	122.5		115.3
Appalachian Power Co [Member] | Vertically Integrated Utilities [Member]
Revenues
Revenue from Contracts with Customers	764.2		697.0
Appalachian Power Co [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	2.7		2.7
TOTAL REVENUES	0.2	[3]	0.0	[4]
Appalachian Power Co [Member] | Fuel and Other Consumables Used for Electric Generation [Member]
Expenses
Cost of Goods and Services Sold	163.9		111.0
Appalachian Power Co [Member] | Purchased Electricity for Resale [Member]
Expenses
Cost of Goods and Services Sold	90.1		122.6
Indiana Michigan Power Co [Member]
Revenues
Sales to AEP Affiliates	0.8		2.9
Other Revenues - Affiliated	14.3		12.5
TOTAL REVENUES	564.5		570.3
Expenses
Purchased Electricity from AEP Affiliates	51.6		36.2
Other Operation	154.6		144.7
Maintenance	49.0		49.1
Depreciation and Amortization	109.2		93.9
Taxes Other Than Income Taxes	26.2		26.4
TOTAL EXPENSES	474.2		453.6
OPERATING INCOME (LOSS)	90.3		116.7
Other Income (Expense):
Other Income	3.0		2.5
Allowance for Equity Funds Used During Construction	3.5		2.0
Non-Service Cost Components of Net Periodic Benefit Cost	4.1		4.2
Interest Expense	(27.3)		(30.7)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	70.1		92.7
Income Tax Expense (Benefit)	(0.7)		0.4
Net Income (Loss)	70.8		92.3
Indiana Michigan Power Co [Member] | Vertically Integrated Utilities [Member]
Revenues
Revenue from Contracts with Customers	547.7		553.4
Indiana Michigan Power Co [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	1.7		1.5
Sales to AEP Affiliates	16.0		16.0
TOTAL REVENUES	0.0	[3]	0.0	[4]
Indiana Michigan Power Co [Member] | Fuel and Other Consumables Used for Electric Generation [Member]
Expenses
Cost of Goods and Services Sold	36.3		53.2
Indiana Michigan Power Co [Member] | Purchased Electricity for Resale [Member]
Expenses
Cost of Goods and Services Sold	47.3		50.1
Ohio Power Co [Member]
Revenues
Sales to AEP Affiliates	4.8		8.4
TOTAL REVENUES	723.9		690.3
Expenses
Purchased Electricity from AEP Affiliates	30.1		42.4
Other Operation	184.6		177.3
Maintenance	38.7		31.6
Depreciation and Amortization	75.1		70.5
Taxes Other Than Income Taxes	121.3		112.0
TOTAL EXPENSES	625.1		582.9
OPERATING INCOME (LOSS)	98.8		107.4
Other Income (Expense):
Interest Income	0.2		0.2
Carrying Costs Income	0.5		0.4
Allowance for Equity Funds Used During Construction	2.7		1.9
Non-Service Cost Components of Net Periodic Benefit Cost	3.7		3.8
Interest Expense	(31.6)		(28.9)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	74.3		84.8
Income Tax Expense (Benefit)	6.1		9.7
Net Income (Loss)	68.2		75.1
Ohio Power Co [Member] | Transmission and Distribution Utilities [Member]
Revenues
Revenue from Contracts with Customers	716.7		679.2
Ohio Power Co [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	2.4		2.7
TOTAL REVENUES	5.3	[3]	6.1	[4]
Ohio Power Co [Member] | Purchased Electricity for Resale [Member]
Expenses
Cost of Goods and Services Sold	175.3		149.1
Public Service Co Of Oklahoma [Member]
Revenues
Sales to AEP Affiliates	1.0		1.1
TOTAL REVENUES	296.1		297.3
Expenses
Other Operation	79.1		87.2
Maintenance	24.4		24.4
Depreciation and Amortization	49.9		44.7
Taxes Other Than Income Taxes	12.5		11.3
TOTAL EXPENSES	286.8		294.9
OPERATING INCOME (LOSS)	9.3		2.4
Other Income (Expense):
Interest Income	0.1		0.1
Allowance for Equity Funds Used During Construction	0.4		1.0
Non-Service Cost Components of Net Periodic Benefit Cost	2.1		2.1
Interest Expense	(14.4)		(15.8)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	(2.5)		(10.2)
Income Tax Expense (Benefit)	0.2		0.1
Net Income (Loss)	(2.7)		(10.3)
Public Service Co Of Oklahoma [Member] | Vertically Integrated Utilities [Member]
Revenues
Revenue from Contracts with Customers	293.6		295.4
Public Service Co Of Oklahoma [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	1.5		0.8
TOTAL REVENUES	0.0	[3]	0.0	[4]
Public Service Co Of Oklahoma [Member] | Purchased Electricity, Fuel and Other Consumables Used for Electric Generation [Member]
Expenses
Cost of Goods and Services Sold	120.9		127.3
Southwestern Electric Power Co [Member]
Revenues
Sales to AEP Affiliates	7.8		7.5
TOTAL REVENUES	616.1		385.9
Expenses
Other Operation	90.3		92.2
Maintenance	34.0		33.8
Depreciation and Amortization	69.6		67.3
Taxes Other Than Income Taxes	30.0		25.3
TOTAL EXPENSES	523.7		350.8
OPERATING INCOME (LOSS)	92.4		35.1
Other Income (Expense):
Interest Income	1.0		0.6
Allowance for Equity Funds Used During Construction	2.1		1.4
Non-Service Cost Components of Net Periodic Benefit Cost	2.1		2.1
Interest Expense	(29.3)		(30.1)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	68.3		9.1
Income Tax Expense (Benefit)	5.6		(6.2)
Equity Earnings (Loss) of Unconsolidated Subsidiaries	0.7		0.8
Net Income (Loss)	63.4		16.1
Net Income (Loss) Attributable to Noncontrolling Interests	1.0		1.0
Earnings Attributable to Common Shareholders	62.4		15.1
Southwestern Electric Power Co [Member] | Vertically Integrated Utilities [Member]
Revenues
Revenue from Contracts with Customers	607.7		377.6
Southwestern Electric Power Co [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	0.6		0.8
TOTAL REVENUES	0.0	[3]	0.0	[4]
Southwestern Electric Power Co [Member] | Purchased Electricity, Fuel and Other Consumables Used for Electric Generation [Member]
Expenses
Cost of Goods and Services Sold	$ 299.8		$ 132.2

[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.