Consolidated Statements of Income - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020		Mar. 31, 2019
Revenues
Revenue from Contracts with Customers	$ 3,747.5		$ 4,056.8
Sales to AEP Affiliates	0.0		0.0
TOTAL REVENUES	3,747.5		4,056.8
Expenses
Other Operation	602.1		666.0
Maintenance	249.5		274.5
Depreciation and Amortization	672.2		605.8
Taxes Other Than Income Taxes	321.1		309.9
TOTAL EXPENSES	2,995.9		3,268.4
OPERATING INCOME (LOSS)	751.6		788.4
Other Income (Expense):
Other Income	(4.4)		8.6
Allowance for Equity Funds Used During Construction	31.4		28.9
Non-Service Cost Components of Net Periodic Benefit Cost	29.7		30.0
Interest Expense	(292.1)		(255.8)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	516.2		600.1
Income Tax Expense (Benefit)	46.5		44.5
Equity Earnings (Loss) of Unconsolidated Subsidiaries	29.6		18.5
Net Income (Loss)	499.3		574.1
Net Income (Loss) Attributable to Noncontrolling Interests	4.1		1.3
Earnings Attributable to Common Shareholders	$ 495.2		$ 572.8
Earnings Per Share
Weighted Average Number of Basic AEP Common Shares Outstanding	494,596,869		493,309,076
Total Basic Earnings Per Share Attributable to AEP Common Shareholders	$ 1.00		$ 1.16
Weighted Average Number of Diluted AEP Common Shares Outstanding	496,608,918		494,484,144
Total Diluted Earnings Per Share Attributable to AEP Common Shareholders	$ 1.00		$ 1.16
Common Stock, Dividends Per Share, Declared	$ 0.70		$ 0.67
Vertically Integrated Utilities [Member]
Revenues
Revenue from Contracts with Customers	$ 2,193.0		$ 2,372.3
Transmission and Distribution Utilities [Member]
Revenues
Revenue from Contracts with Customers	1,075.2		1,179.8
Generation and Marketing [Member]
Revenues
Revenue from Contracts with Customers	408.4		439.7
Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	70.9		65.0
Fuel and Other Consumables Used for Electric Generation [Member]
Revenues
Revenue from Contracts with Customers	184.5		294.7
Expenses
Cost of Goods and Services Sold	355.3		550.4
Purchased Electricity for Resale [Member]
Expenses
Cost of Goods and Services Sold	795.7		861.8
AEP Texas Inc. [Member]
Revenues
Sales to AEP Affiliates	31.1		40.2
TOTAL REVENUES	423.6		390.7
Expenses
Other Operation	117.5		109.8
Maintenance	20.6		25.3
Depreciation and Amortization	162.5		138.9
Taxes Other Than Income Taxes	34.0		36.5
TOTAL EXPENSES	334.6		319.9
OPERATING INCOME (LOSS)	89.0		70.8
Other Income (Expense):
Interest Income	0.6		0.4
Allowance for Equity Funds Used During Construction	5.1		1.8
Non-Service Cost Components of Net Periodic Benefit Cost	2.8		2.8
Interest Expense	(42.5)		(37.4)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	55.0		38.4
Income Tax Expense (Benefit)	7.4		4.0
Net Income (Loss)	47.6		34.4
AEP Texas Inc. [Member] | Transmission and Distribution Utilities [Member]
Revenues
Revenue from Contracts with Customers	391.6		349.8
AEP Texas Inc. [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	0.9		0.7
AEP Texas Inc. [Member] | Fuel and Other Consumables Used for Electric Generation [Member]
Revenues
Revenue from Contracts with Customers	0.0	[1]	0.0	[2]
Expenses
Cost of Goods and Services Sold	0.0		9.4
AEP Transmission Co [Member]
Revenues
Sales to AEP Affiliates	233.7		193.2
TOTAL REVENUES	295.6		243.5
Expenses
Other Operation	23.8		17.0
Maintenance	3.2		3.2
Depreciation and Amortization	56.0		40.3
Taxes Other Than Income Taxes	50.4		41.4
TOTAL EXPENSES	133.4		101.9
OPERATING INCOME (LOSS)	162.2		141.6
Other Income (Expense):
Interest Income	0.8		0.7
Allowance for Equity Funds Used During Construction	16.2		11.3
Interest Expense	(29.6)		(21.7)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	149.6		131.9
Income Tax Expense (Benefit)	31.8		27.6
Net Income (Loss)	117.8		104.3
AEP Transmission Co [Member] | Transmission [Member]
Revenues
Revenue from Contracts with Customers	61.3		50.3
AEP Transmission Co [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	0.6		0.0
AEP Transmission Co [Member] | Fuel and Other Consumables Used for Electric Generation [Member]
Revenues
Revenue from Contracts with Customers	0.0	[1]	0.0	[2]
Appalachian Power Co [Member]
Revenues
Sales to AEP Affiliates	49.7		51.7
TOTAL REVENUES	749.4		792.8
Expenses
Other Operation	134.0		136.9
Maintenance	50.3		61.5
Depreciation and Amortization	122.2		112.5
Taxes Other Than Income Taxes	37.9		35.9
TOTAL EXPENSES	578.0		640.7
OPERATING INCOME (LOSS)	171.4		152.1
Other Income (Expense):
Interest Income	0.3		0.8
Allowance for Equity Funds Used During Construction	2.4		1.7
Non-Service Cost Components of Net Periodic Benefit Cost	4.7		4.3
Interest Expense	(53.1)		(49.3)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	125.7		109.6
Income Tax Expense (Benefit)	10.4		(24.1)
Net Income (Loss)	115.3		133.7
Appalachian Power Co [Member] | Vertically Integrated Utilities [Member]
Revenues
Revenue from Contracts with Customers	697.0		738.7
Appalachian Power Co [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	2.7		2.4
Appalachian Power Co [Member] | Fuel and Other Consumables Used for Electric Generation [Member]
Revenues
Revenue from Contracts with Customers	54.1	[1]	67.5	[2]
Sales to AEP Affiliates	33.0		35.0
Expenses
Cost of Goods and Services Sold	111.0		183.3
Appalachian Power Co [Member] | Purchased Electricity for Resale [Member]
Expenses
Cost of Goods and Services Sold	122.6		110.6
Indiana Michigan Power Co [Member]
Revenues
Sales to AEP Affiliates	2.9		2.3
Other Revenues - Affiliated	12.5		13.3
TOTAL REVENUES	570.3		614.3
Expenses
Purchased Electricity from AEP Affiliates	36.2		59.8
Other Operation	144.7		140.5
Maintenance	49.1		58.3
Depreciation and Amortization	93.9		86.2
Taxes Other Than Income Taxes	26.4		27.3
TOTAL EXPENSES	453.6		499.3
OPERATING INCOME (LOSS)	116.7		115.0
Other Income (Expense):
Other Income	2.5		5.7
Allowance for Equity Funds Used During Construction	2.0		6.2
Non-Service Cost Components of Net Periodic Benefit Cost	4.2		4.4
Interest Expense	(30.7)		(28.9)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	92.7		96.2
Income Tax Expense (Benefit)	0.4		(2.7)
Net Income (Loss)	92.3		98.9
Indiana Michigan Power Co [Member] | Vertically Integrated Utilities [Member]
Revenues
Revenue from Contracts with Customers	553.4		596.7
Indiana Michigan Power Co [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	1.5		2.0
Sales to AEP Affiliates	16.0		15.0
Indiana Michigan Power Co [Member] | Fuel and Other Consumables Used for Electric Generation [Member]
Revenues
Revenue from Contracts with Customers	78.4	[1]	111.9	[2]
Expenses
Cost of Goods and Services Sold	53.2		57.6
Indiana Michigan Power Co [Member] | Purchased Electricity for Resale [Member]
Expenses
Cost of Goods and Services Sold	50.1		69.6
Ohio Power Co [Member]
Revenues
Sales to AEP Affiliates	8.4		7.5
TOTAL REVENUES	690.3		836.8
Expenses
Purchased Electricity from AEP Affiliates	42.4		46.1
Amortization of Generation Deferrals	0.0		32.4
Other Operation	177.3		216.9
Maintenance	31.6		32.5
Depreciation and Amortization	70.5		63.3
Taxes Other Than Income Taxes	112.0		108.9
TOTAL EXPENSES	582.9		674.3
OPERATING INCOME (LOSS)	107.4		162.5
Other Income (Expense):
Interest Income	0.2		0.8
Carrying Costs Income	0.4		0.2
Allowance for Equity Funds Used During Construction	1.9		5.2
Non-Service Cost Components of Net Periodic Benefit Cost	3.8		3.7
Interest Expense	(28.9)		(24.6)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	84.8		147.8
Income Tax Expense (Benefit)	9.7		19.8
Net Income (Loss)	75.1		128.0
Ohio Power Co [Member] | Transmission and Distribution Utilities [Member]
Revenues
Revenue from Contracts with Customers	679.2		826.5
Ohio Power Co [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	2.7		2.8
Ohio Power Co [Member] | Fuel and Other Consumables Used for Electric Generation [Member]
Revenues
Revenue from Contracts with Customers	0.0	[1]	0.0	[2]
Ohio Power Co [Member] | Purchased Electricity for Resale [Member]
Expenses
Cost of Goods and Services Sold	149.1		174.2
Public Service Co Of Oklahoma [Member]
Revenues
Sales to AEP Affiliates	1.1		1.6
TOTAL REVENUES	297.3		332.8
Expenses
Other Operation	87.2		73.6
Maintenance	24.4		22.5
Depreciation and Amortization	44.7		43.5
Taxes Other Than Income Taxes	11.3		11.4
TOTAL EXPENSES	294.9		311.9
OPERATING INCOME (LOSS)	2.4		20.9
Other Income (Expense):
Interest Income	0.1		0.0
Allowance for Equity Funds Used During Construction	1.0		0.1
Non-Service Cost Components of Net Periodic Benefit Cost	2.1		2.1
Interest Expense	(15.8)		(16.9)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	(10.2)		6.2
Income Tax Expense (Benefit)	0.1		0.0
Net Income (Loss)	(10.3)		6.2
Public Service Co Of Oklahoma [Member] | Vertically Integrated Utilities [Member]
Revenues
Revenue from Contracts with Customers	295.4		329.2
Public Service Co Of Oklahoma [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	0.8		2.0
Public Service Co Of Oklahoma [Member] | Fuel and Other Consumables Used for Electric Generation [Member]
Revenues
Revenue from Contracts with Customers	1.9	[1]	8.6	[2]
Expenses
Cost of Goods and Services Sold	16.9		38.0
Public Service Co Of Oklahoma [Member] | Purchased Electricity for Resale [Member]
Expenses
Cost of Goods and Services Sold	110.4		122.9
Southwestern Electric Power Co [Member]
Revenues
Sales to AEP Affiliates	7.5		6.4
TOTAL REVENUES	385.9		421.1
Expenses
Other Operation	92.2		84.6
Maintenance	33.8		28.9
Depreciation and Amortization	67.3		62.1
Taxes Other Than Income Taxes	25.3		25.3
TOTAL EXPENSES	350.8		367.0
OPERATING INCOME (LOSS)	35.1		54.1
Other Income (Expense):
Interest Income	0.6		0.7
Allowance for Equity Funds Used During Construction	1.4		1.8
Non-Service Cost Components of Net Periodic Benefit Cost	2.1		2.1
Interest Expense	(30.1)		(29.7)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	9.1		29.0
Income Tax Expense (Benefit)	(6.2)		0.7
Equity Earnings (Loss) of Unconsolidated Subsidiaries	0.8		0.7
Net Income (Loss)	16.1		29.0
Net Income (Loss) Attributable to Noncontrolling Interests	1.0		1.2
Earnings Attributable to Common Shareholders	15.1		27.8
Southwestern Electric Power Co [Member] | Vertically Integrated Utilities [Member]
Revenues
Revenue from Contracts with Customers	377.6		414.3
Southwestern Electric Power Co [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	0.8		0.4
Southwestern Electric Power Co [Member] | Fuel and Other Consumables Used for Electric Generation [Member]
Revenues
Revenue from Contracts with Customers	34.1	[1]	57.2	[2]
Expenses
Cost of Goods and Services Sold	89.1		133.5
Southwestern Electric Power Co [Member] | Purchased Electricity for Resale [Member]
Expenses
Cost of Goods and Services Sold	$ 43.1		$ 32.6

[1] Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for APCo was $33 million primarily relating to the PPA with KGPCo. The remaining affiliated amounts were immaterial.

[2] Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for APCo was $35 million primarily relating to the PPA with KGPCo. The remaining affiliated amounts were immaterial.