Consolidated Statements of Income - USD ($) $ in Millions	3 Months Ended				9 Months Ended
	Sep. 30, 2019		Sep. 30, 2018		Sep. 30, 2019		Sep. 30, 2018
Revenues
Revenue from Contracts with Customers	$ 4,315.0		$ 4,333.1		$ 11,945.4		$ 12,394.6
Sales to AEP Affiliates	0.0		0.0		0.0		0.0
TOTAL REVENUES	4,315.0		4,333.1		11,945.4		12,394.6
Expenses
Other Operation	708.3		826.0		1,981.7		2,332.7
Maintenance	267.7		316.6		890.9		911.0
Depreciation and Amortization	645.2		602.6		1,873.6		1,695.5
Taxes Other Than Income Taxes	320.5		294.2		932.7		863.0
TOTAL EXPENSES	3,356.8		3,664.5		9,647.8		10,263.0
OPERATING INCOME (LOSS)	958.2		668.6		2,297.6		2,131.6
Other Income (Expense):
Other Income	3.2		6.3		18.4		18.5
Allowance for Equity Funds Used During Construction	43.0		30.9		122.3		92.4
Non-Service Cost Components of Net Periodic Benefit Cost	30.0		31.9		90.0		95.3
Interest Expense	(275.1)		(256.8)		(781.6)		(733.1)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	759.3		480.9		1,746.7		1,604.7
Income Tax Expense (Benefit)	40.6		(80.7)		30.7		93.5
Equity Earnings (Loss) of Unconsolidated Subsidiaries	15.2		18.1		51.1		55.3
Net Income (Loss)	733.9		579.7		1,767.1		1,566.5
Net Income (Loss) Attributable to Noncontrolling Interests	0.4		2.1		(0.5)		6.1
Earnings Attributable to Common Shareholders	$ 733.5		$ 577.6		$ 1,767.6		$ 1,560.4
Earnings Per Share
Weighted Average Number of Basic AEP Common Shares Outstanding	493,839,034		492,984,741		493,579,430		492,649,456
Total Basic Earnings Per Share Attributable to AEP Common Shareholders	$ 1.49		$ 1.17		$ 3.58		$ 3.17
Weighted Average Number of Diluted AEP Common Shares Outstanding	495,461,509		493,940,543		495,105,986		493,526,937
Total Diluted Earnings Per Share Attributable to AEP Common Shareholders	$ 1.48		$ 1.17		$ 3.57		$ 3.16
Common Stock, Dividends Per Share, Declared	$ 0.67		$ 0.62
Vertically Integrated Utilities [Member]
Revenues
Revenue from Contracts with Customers	$ 2,598.9		$ 2,610.2		$ 7,087.6		$ 7,332.4
Transmission and Distribution Utilities [Member]
Revenues
Revenue from Contracts with Customers	1,147.3		1,180.9		3,328.7		3,450.0
Generation and Marketing [Member]
Revenues
Revenue from Contracts with Customers	501.2		486.5		1,323.8		1,399.3
Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	67.6		55.5		205.3		212.9
Fuel and Other Consumables Used for Electric Generation [Member]
Revenues
Revenue from Contracts with Customers	274.2	[1]	240.8	[2]	838.4	[3]	944.7	[4]
Expenses
Cost of Goods and Services Sold	631.2		840.4		1,662.5		1,909.1
Purchased Electricity for Resale [Member]
Expenses
Cost of Goods and Services Sold	783.9		784.7		2,306.4		2,551.7
AEP Texas Inc. [Member]
Revenues
Sales to AEP Affiliates	42.7		27.5		125.1		63.3
TOTAL REVENUES	489.3		433.4		1,318.0		1,193.3
Expenses
Other Operation	128.2		133.4		349.2		368.4
Maintenance	21.7		23.2		136.9		67.8
Depreciation and Amortization	170.2		133.3		464.8		364.9
Taxes Other Than Income Taxes	39.8		36.3		110.3		102.3
TOTAL EXPENSES	371.1		339.4		1,090.3		931.3
OPERATING INCOME (LOSS)	118.2		94.0		227.7		262.0
Other Income (Expense):
Interest Income	0.4		0.5		1.5		0.0
Allowance for Equity Funds Used During Construction	5.1		5.8		8.3		15.2
Non-Service Cost Components of Net Periodic Benefit Cost	2.8		3.1		8.4		9.2
Interest Expense	(35.8)		(37.3)		(92.7)		(108.9)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	90.7		66.1		153.2		177.5
Income Tax Expense (Benefit)	13.7		8.3		(38.8)		26.4
Net Income (Loss)	77.0		57.8		192.0		151.1
AEP Texas Inc. [Member] | Transmission and Distribution Utilities [Member]
Revenues
Revenue from Contracts with Customers	445.4		404.5		1,190.3		1,127.0
AEP Texas Inc. [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	1.2		1.4		2.6		3.0
AEP Texas Inc. [Member] | Fuel and Other Consumables Used for Electric Generation [Member]
Revenues
Revenue from Contracts with Customers	0.0	[5]	0.0	[6]	0.0	[7]	0.0	[8]
Expenses
Cost of Goods and Services Sold	11.2		13.2		29.1		27.9
AEP Transmission Co [Member]
Revenues
Sales to AEP Affiliates	205.7		148.4		608.0		453.8
TOTAL REVENUES	259.7		194.4		770.1		586.2
Expenses
Other Operation	26.0		24.5		61.7		59.6
Maintenance	3.2		2.8		8.9		7.6
Depreciation and Amortization	45.3		34.9		128.4		97.5
Taxes Other Than Income Taxes	42.9		35.2		126.2		102.9
TOTAL EXPENSES	117.4		97.4		325.2		267.6
OPERATING INCOME (LOSS)	142.3		97.0		444.9		318.6
Other Income (Expense):
Interest Income	0.8		0.5		2.1		1.3
Allowance for Equity Funds Used During Construction	21.0		18.0		61.1		48.7
Interest Expense	(26.4)		(19.8)		(69.5)		(60.7)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	137.7		95.7		438.6		307.9
Income Tax Expense (Benefit)	30.1		17.6		90.7		63.7
Net Income (Loss)	107.6		78.1		347.9		244.2
AEP Transmission Co [Member] | Transmission [Member]
Revenues
Revenue from Contracts with Customers	54.0		46.0		162.1		132.3
AEP Transmission Co [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	0.0		0.0		0.0		0.1
AEP Transmission Co [Member] | Fuel and Other Consumables Used for Electric Generation [Member]
Revenues
Revenue from Contracts with Customers	0.0	[5]	0.0	[6]	0.0	[7]	0.0	[8]
Appalachian Power Co [Member]
Revenues
Sales to AEP Affiliates	56.6		42.9		154.6		138.7
TOTAL REVENUES	755.5		762.0		2,204.1		2,249.4
Expenses
Other Operation	140.4		131.9		416.2		380.0
Maintenance	61.5		97.2		184.3		234.9
Depreciation and Amortization	118.7		105.7		348.3		319.5
Taxes Other Than Income Taxes	36.7		33.6		108.5		101.1
TOTAL EXPENSES	612.9		712.2		1,832.5		1,874.0
OPERATING INCOME (LOSS)	142.6		49.8		371.6		375.4
Other Income (Expense):
Interest Income	0.3		0.4		2.1		1.3
Carrying Costs Income	0.0		0.2		0.0		1.2
Allowance for Equity Funds Used During Construction	4.8		4.1		12.5		9.6
Non-Service Cost Components of Net Periodic Benefit Cost	4.3		4.5		12.8		13.4
Interest Expense	(51.6)		(50.8)		(152.5)		(146.0)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	100.4		8.2		246.5		254.9
Income Tax Expense (Benefit)	(3.9)		(78.9)		(47.0)		(35.1)
Net Income (Loss)	104.3		87.1		293.5		290.0
Appalachian Power Co [Member] | Vertically Integrated Utilities [Member]
Revenues
Revenue from Contracts with Customers	696.7		716.8		2,041.3		2,103.1
Appalachian Power Co [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	2.2		2.3		8.2		7.6
Appalachian Power Co [Member] | Fuel and Other Consumables Used for Electric Generation [Member]
Revenues
Revenue from Contracts with Customers	70.4	[5]	74.5	[6]	200.1	[7]	194.1	[8]
Sales to AEP Affiliates	32.0		30.0		96.0		100.0
Expenses
Cost of Goods and Services Sold	177.3		263.4		521.8		487.7
Appalachian Power Co [Member] | Purchased Electricity for Resale [Member]
Expenses
Cost of Goods and Services Sold	78.3		80.4		253.4		350.8
Indiana Michigan Power Co [Member]
Revenues
Sales to AEP Affiliates	2.7		3.4		7.3		18.9
Other Revenues - Affiliated	16.2		13.7		50.4		43.3
TOTAL REVENUES	611.1		629.7		1,768.5		1,796.2
Expenses
Purchased Electricity from AEP Affiliates	61.0		60.0		172.1		181.8
Other Operation	172.7		149.3		467.7		425.8
Maintenance	50.9		57.2		163.8		169.1
Depreciation and Amortization	88.1		85.2		261.6		207.1
Taxes Other Than Income Taxes	25.1		23.0		78.6		72.9
TOTAL EXPENSES	503.8		519.5		1,468.3		1,471.2
OPERATING INCOME (LOSS)	107.3		110.2		300.2		325.0
Other Income (Expense):
Other Income	3.5		6.1		15.3		15.4
Allowance for Equity Funds Used During Construction					16.4		8.0
Non-Service Cost Components of Net Periodic Benefit Cost	4.5		4.6		13.3		13.6
Interest Expense	(28.8)		(34.5)		(85.9)		(95.6)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	86.5		86.4		242.9		258.4
Income Tax Expense (Benefit)	(2.3)		13.7		(5.1)		26.8
Net Income (Loss)	88.8		72.7		248.0		231.6
Indiana Michigan Power Co [Member] | Vertically Integrated Utilities [Member]
Revenues
Revenue from Contracts with Customers	589.1		609.9		1,703.2		1,723.9
Indiana Michigan Power Co [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	3.1		2.7		7.6		10.1
Sales to AEP Affiliates	20.0		17.0		57.0		57.0
Indiana Michigan Power Co [Member] | Fuel and Other Consumables Used for Electric Generation [Member]
Revenues
Revenue from Contracts with Customers	102.1	[5]	93.6	[6]	327.4	[7]	349.7	[8]
Expenses
Cost of Goods and Services Sold	61.2		95.9		161.2		246.8
Indiana Michigan Power Co [Member] | Purchased Electricity for Resale [Member]
Expenses
Cost of Goods and Services Sold	44.8		48.9		163.3		167.7
Ohio Power Co [Member]
Revenues
Sales to AEP Affiliates	9.0		3.3		18.2		17.9
TOTAL REVENUES	710.6		778.3		2,154.0		2,318.0
Expenses
Purchased Electricity from AEP Affiliates	40.6		39.3		120.4		97.4
Amortization of Generation Deferrals	8.8		56.9		65.3		171.9
Other Operation	194.9		215.2		565.7		586.4
Maintenance	40.0		43.4		106.7		114.7
Depreciation and Amortization	57.4		70.4		176.8		200.3
Taxes Other Than Income Taxes	112.0		106.9		326.9		311.0
TOTAL EXPENSES	612.0		698.4		1,815.8		2,016.4
OPERATING INCOME (LOSS)	98.6		79.9		338.2		301.6
Other Income (Expense):
Interest Income	0.8		0.8		2.7		2.6
Carrying Costs Income	0.3		0.2		0.7		1.5
Allowance for Equity Funds Used During Construction	4.8		2.0		14.1		7.8
Non-Service Cost Components of Net Periodic Benefit Cost	3.7		3.8		11.0		11.6
Interest Expense	(27.9)		(26.1)		(78.1)		(76.6)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	80.3		60.6		288.6		248.5
Income Tax Expense (Benefit)	11.2		(28.1)		40.9		11.4
Net Income (Loss)	69.1		88.7		247.7		237.1
Ohio Power Co [Member] | Transmission and Distribution Utilities [Member]
Revenues
Revenue from Contracts with Customers	698.6		772.6		2,127.4		2,294.8
Ohio Power Co [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	3.0		2.4		8.4		5.3
Ohio Power Co [Member] | Fuel and Other Consumables Used for Electric Generation [Member]
Revenues
Revenue from Contracts with Customers	0.0	[5]	0.0	[6]	0.0	[7]	0.0	[8]
Ohio Power Co [Member] | Purchased Electricity for Resale [Member]
Expenses
Cost of Goods and Services Sold	158.3		166.3		454.0		534.7
Public Service Co Of Oklahoma [Member]
Revenues
Sales to AEP Affiliates	1.3		1.1		5.0		3.7
TOTAL REVENUES	493.0		481.4		1,173.9		1,216.5
Expenses
Other Operation	87.6		106.3		226.0		286.8
Maintenance	21.5		22.3		70.1		73.2
Depreciation and Amortization	39.1		42.3		125.4		120.5
Taxes Other Than Income Taxes	11.1		10.8		33.0		32.6
TOTAL EXPENSES	373.0		402.9		976.4		1,076.9
OPERATING INCOME (LOSS)	120.0		78.5		197.5		139.6
Other Income (Expense):
Other Income	1.2		(0.2)		2.1		(0.3)
Allowance for Equity Funds Used During Construction					1.5		(0.3)
Non-Service Cost Components of Net Periodic Benefit Cost	2.1		2.1		6.3		6.5
Interest Expense	(16.1)		(16.4)		(50.3)		(47.4)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	107.2		64.0		155.6		98.4
Income Tax Expense (Benefit)	6.9		3.6		7.2		8.6
Net Income (Loss)	100.3		60.4		148.4		89.8
Public Service Co Of Oklahoma [Member] | Vertically Integrated Utilities [Member]
Revenues
Revenue from Contracts with Customers	490.5		479.1		1,164.3		1,209.5
Public Service Co Of Oklahoma [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	1.2		1.2		4.6		3.3
Public Service Co Of Oklahoma [Member] | Fuel and Other Consumables Used for Electric Generation [Member]
Revenues
Revenue from Contracts with Customers	21.1	[5]	12.5	[6]	35.5	[7]	26.7	[8]
Expenses
Cost of Goods and Services Sold	98.4		104.4		181.2		211.5
Public Service Co Of Oklahoma [Member] | Purchased Electricity for Resale [Member]
Expenses
Cost of Goods and Services Sold	115.3		116.8		340.7		352.3
Southwestern Electric Power Co [Member]
Revenues
Sales to AEP Affiliates	8.8		8.7		21.6		20.2
Provision for Refund	(0.1)		0.0		(25.3)		0.0
TOTAL REVENUES	545.5		535.3		1,342.1		1,411.8
Expenses
Other Operation	91.9		99.1		242.4		292.0
Maintenance	35.9		33.6		104.1		102.2
Depreciation and Amortization	63.2		59.9		187.1		175.9
Taxes Other Than Income Taxes	26.2		26.9		76.0		76.4
TOTAL EXPENSES	410.8		408.2		1,120.3		1,172.6
OPERATING INCOME (LOSS)	134.7		127.1		221.8		239.2
Other Income (Expense):
Interest Income	0.6		1.1		2.0		3.5
Allowance for Equity Funds Used During Construction	1.6		0.6		4.5		3.8
Non-Service Cost Components of Net Periodic Benefit Cost	2.1		2.3		6.4		6.9
Interest Expense	(29.2)		(32.7)		(89.4)		(95.8)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	109.8		98.4		145.3		157.6
Income Tax Expense (Benefit)	(0.7)		9.6		0.0		17.9
Equity Earnings (Loss) of Unconsolidated Subsidiaries	0.8		0.8		2.3		2.0
Net Income (Loss)	111.3		89.6		147.6		141.7
Net Income (Loss) Attributable to Noncontrolling Interests	0.8		1.4		3.1		4.1
Earnings Attributable to Common Shareholders	110.5		88.2		144.5		137.6
Southwestern Electric Power Co [Member] | Vertically Integrated Utilities [Member]
Revenues
Revenue from Contracts with Customers	536.5		526.0		1,344.8		1,390.4
Southwestern Electric Power Co [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	0.3		0.6		1.0		1.2
Southwestern Electric Power Co [Member] | Fuel and Other Consumables Used for Electric Generation [Member]
Revenues
Revenue from Contracts with Customers	50.7	[5]	53.2	[6]	152.7	[7]	168.8	[8]
Expenses
Cost of Goods and Services Sold	148.8		152.1		400.2		393.4
Southwestern Electric Power Co [Member] | Purchased Electricity for Resale [Member]
Expenses
Cost of Goods and Services Sold	$ 44.8		$ 36.6		$ 110.5		$ 132.7

[1] Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for Generation & Marketing was $34 million. The remaining affiliated amounts were immaterial.

[2] Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for Generation & Marketing was $35 million. The remaining affiliated amounts were immaterial.

[3] Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for Generation & Marketing was $105 million. The remaining affiliated amounts were immaterial.

[4] Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for Generation & Marketing was $87 million. The remaining affiliated amounts were immaterial

[5] Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for APCo was $32 million primarily relating to the PPA with Kingsport. The remaining affiliated amounts were immaterial.

[6] Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for APCo was $30 million primarily relating to the PPA with Kingsport. The remaining affiliated amounts were immaterial.

[7] Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for APCo was $96 million primarily relating to the PPA with Kingsport. The remaining affiliated amounts were immaterial.

[8] Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for APCo was $100 million primarily relating to the PPA with Kingsport. The remaining affiliated amounts were immaterial.