Consolidated Statements of Income - USD ($) $ in Millions	3 Months Ended				9 Months Ended
	Sep. 30, 2020		Sep. 30, 2019		Sep. 30, 2020		Sep. 30, 2019
Revenues
Revenue from Contracts with Customers	$ 4,066.4		$ 4,315.0		$ 11,307.9		$ 11,945.4
Sales to AEP Affiliates	0.0		0.0		0.0		0.0
TOTAL REVENUES	4,066.4		4,315.0		11,307.9		11,945.4
Expenses
Other Operation	702.9		708.3		1,871.0		1,981.7
Maintenance	237.6		267.7		730.5		890.9
Depreciation and Amortization	644.6		645.2		1,996.3		1,873.6
Taxes Other Than Income Taxes	337.7		320.5		976.3		932.7
TOTAL EXPENSES	3,123.2		3,356.8		8,890.4		9,647.8
OPERATING INCOME (LOSS)	943.2		958.2		2,417.5		2,297.6
Other Income (Expense):
Other Income	5.5		3.2		15.4		18.4
Allowance for Equity Funds Used During Construction	45.2		43.0		111.7		122.3
Non-Service Cost Components of Net Periodic Benefit Cost	29.7		30.0		89.2		90.0
Interest Expense	(291.3)		(275.1)		(877.4)		(781.6)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	732.3		759.3		1,756.4		1,746.7
Income Tax Expense (Benefit)	(1.2)		40.6		57.9		30.7
Equity Earnings (Loss) of Unconsolidated Subsidiaries	14.7		15.2		63.5		51.1
Net Income (Loss)	748.2		733.9		1,762.0		1,767.1
Net Income (Loss) Attributable to Noncontrolling Interests	(0.4)		0.4		(2.6)		(0.5)
Earnings Attributable to Common Shareholders	$ 748.6		$ 733.5		$ 1,764.6		$ 1,767.6
Earnings Per Share
Weighted Average Number of Basic AEP Common Shares Outstanding	496,177,968		493,839,034		495,479,190		493,579,430
Total Basic Earnings Per Share Attributable to AEP Common Shareholders	$ 1.51		$ 1.49		$ 3.56		$ 3.58
Weighted Average Number of Diluted AEP Common Shares Outstanding	497,458,523		495,461,509		496,916,187		495,105,986
Total Diluted Earnings Per Share Attributable to AEP Common Shareholders	$ 1.50		$ 1.48		$ 3.55		$ 3.57
Common Stock, Dividends Per Share, Declared	$ 0.70		$ 0.67
Vertically Integrated Utilities [Member]
Revenues
Revenue from Contracts with Customers	$ 2,400.1		$ 2,598.9		$ 6,655.4		$ 7,087.6
Transmission and Distribution Utilities [Member]
Revenues
Revenue from Contracts with Customers	1,124.1		1,147.3		3,208.7		3,328.7
Generation and Marketing [Member]
Revenues
Revenue from Contracts with Customers	464.8		501.2		1,223.4		1,323.8
Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	77.4		67.6		220.4		205.3
TOTAL REVENUES	(5.5)	[1]	14.3	[2]	13.3	[3]	54.6	[4]
Fuel and Other Consumables Used for Electric Generation [Member]
Expenses
Cost of Goods and Services Sold	459.3		631.2		1,174.9		1,662.5
Purchased Electricity for Resale [Member]
Expenses
Cost of Goods and Services Sold	741.1		783.9		2,141.4		2,306.4
AEP Texas Inc. [Member]
Revenues
Sales to AEP Affiliates	41.4		42.7		89.4		125.1
TOTAL REVENUES	432.0		489.3		1,257.1		1,318.0
Expenses
Other Operation	134.3		128.2		344.7		349.2
Maintenance	20.4		21.7		64.1		136.9
Depreciation and Amortization	107.7		170.2		435.8		464.8
Taxes Other Than Income Taxes	38.7		39.8		106.7		110.3
TOTAL EXPENSES	311.5		371.1		964.9		1,090.3
OPERATING INCOME (LOSS)	120.5		118.2		292.2		227.7
Other Income (Expense):
Interest Income	0.5		0.4		1.2		1.5
Allowance for Equity Funds Used During Construction	4.4		5.1		14.4		8.3
Non-Service Cost Components of Net Periodic Benefit Cost	2.8		2.8		8.4		8.4
Interest Expense	(44.5)		(35.8)		(129.2)		(92.7)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	83.7		90.7		187.0		153.2
Income Tax Expense (Benefit)	1.1		13.7		(10.1)		(38.8)
Net Income (Loss)	82.6		77.0		197.1		192.0
AEP Texas Inc. [Member] | Transmission and Distribution Utilities [Member]
Revenues
Revenue from Contracts with Customers	390.1		445.4		1,165.2		1,190.3
AEP Texas Inc. [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	0.5		1.2		2.5		2.6
TOTAL REVENUES	40.6	[5]	41.8	[6]	86.9	[7]	122.6	[8]
AEP Texas Inc. [Member] | Fuel and Other Consumables Used for Electric Generation [Member]
Expenses
Cost of Goods and Services Sold	10.4		11.2		13.6		29.1
AEP Transmission Co [Member]
Revenues
Sales to AEP Affiliates	241.2		205.7		652.6		608.0
TOTAL REVENUES	304.1		259.7		837.8		770.1
Expenses
Other Operation	25.3		26.0		72.0		61.7
Maintenance	3.5		3.2		6.8		8.9
Depreciation and Amortization	61.5		45.3		176.4		128.4
Taxes Other Than Income Taxes	52.2		42.9		152.8		126.2
TOTAL EXPENSES	142.5		117.4		408.0		325.2
OPERATING INCOME (LOSS)	161.6		142.3		429.8		444.9
Other Income (Expense):
Interest Income	0.2		0.8		2.3		2.1
Allowance for Equity Funds Used During Construction	20.2		21.0		54.9		61.1
Interest Expense	(32.7)		(26.4)		(95.1)		(69.5)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	149.3		137.7		391.9		438.6
Income Tax Expense (Benefit)	31.7		30.1		82.8		90.7
Net Income (Loss)	117.6		107.6		309.1		347.9
AEP Transmission Co [Member] | Transmission [Member]
Revenues
Revenue from Contracts with Customers	62.9		54.0		184.6		162.1
AEP Transmission Co [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	0.0		0.0		0.6		0.0
TOTAL REVENUES	0.0	[5]	0.0	[6]	0.0	[7]	0.0	[8]
Appalachian Power Co [Member]
Revenues
Sales to AEP Affiliates	44.4		56.6		124.9		154.6
TOTAL REVENUES	735.7		755.5		2,122.6		2,204.1
Expenses
Other Operation	136.3		140.4		379.1		416.2
Maintenance	52.0		61.5		148.7		184.3
Depreciation and Amortization	123.2		118.7		366.0		348.3
Taxes Other Than Income Taxes	38.8		36.7		114.2		108.5
TOTAL EXPENSES	583.8		612.9		1,679.4		1,832.5
OPERATING INCOME (LOSS)	151.9		142.6		443.2		371.6
Other Income (Expense):
Interest Income	0.6		0.3		1.4		2.1
Allowance for Equity Funds Used During Construction	6.7		4.8		11.5		12.5
Non-Service Cost Components of Net Periodic Benefit Cost	4.7		4.3		14.1		12.8
Interest Expense	(55.0)		(51.6)		(162.2)		(152.5)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	108.9		100.4		308.0		246.5
Income Tax Expense (Benefit)	(7.7)		(3.9)		(5.2)		(47.0)
Net Income (Loss)	116.6		104.3		313.2		293.5
Appalachian Power Co [Member] | Vertically Integrated Utilities [Member]
Revenues
Revenue from Contracts with Customers	688.9		696.7		1,989.9		2,041.3
Appalachian Power Co [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	2.4		2.2		7.8		8.2
TOTAL REVENUES	0.0	[5]	0.0	[6]	0.0	[7]	0.0	[8]
Appalachian Power Co [Member] | Fuel and Other Consumables Used for Electric Generation [Member]
Revenues
Sales to AEP Affiliates	28.0		32.0		85.0		96.0
Expenses
Cost of Goods and Services Sold	166.0		177.3		430.9		521.8
Appalachian Power Co [Member] | Purchased Electricity for Resale [Member]
Expenses
Cost of Goods and Services Sold	67.5		78.3		240.5		253.4
Indiana Michigan Power Co [Member]
Revenues
Sales to AEP Affiliates	1.3		2.7		9.1		7.3
Other Revenues - Affiliated	14.1		16.2		42.4		50.4
TOTAL REVENUES	586.7		611.1		1,703.6		1,768.5
Expenses
Purchased Electricity from AEP Affiliates	55.9		61.0		135.8		172.1
Other Operation	165.5		172.7		459.7		467.7
Maintenance	51.0		50.9		144.4		163.8
Depreciation and Amortization	104.5		88.1		303.6		261.6
Taxes Other Than Income Taxes	27.4		25.1		79.5		78.6
TOTAL EXPENSES	486.2		503.8		1,397.1		1,468.3
OPERATING INCOME (LOSS)	100.5		107.3		306.5		300.2
Other Income (Expense):
Other Income	2.2		3.5		7.8		15.3
Allowance for Equity Funds Used During Construction					8.8		16.4
Non-Service Cost Components of Net Periodic Benefit Cost	4.1		4.5		12.5		13.3
Interest Expense	(26.9)		(28.8)		(85.7)		(85.9)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	79.9		86.5		241.1		242.9
Income Tax Expense (Benefit)	3.2		(2.3)		8.3		(5.1)
Net Income (Loss)	76.7		88.8		232.8		248.0
Indiana Michigan Power Co [Member] | Vertically Integrated Utilities [Member]
Revenues
Revenue from Contracts with Customers	570.1		589.1		1,648.4		1,703.2
Indiana Michigan Power Co [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	1.2		3.1		3.7		7.6
Sales to AEP Affiliates	15.0		20.0		49.0		57.0
TOTAL REVENUES	0.0	[5]	0.0	[6]	0.0	[7]	0.0	[8]
Indiana Michigan Power Co [Member] | Fuel and Other Consumables Used for Electric Generation [Member]
Expenses
Cost of Goods and Services Sold	44.4		61.2		146.0		161.2
Indiana Michigan Power Co [Member] | Purchased Electricity for Resale [Member]
Expenses
Cost of Goods and Services Sold	37.5		44.8		128.1		163.3
Ohio Power Co [Member]
Revenues
Sales to AEP Affiliates	8.3		9.0		33.0		18.2
TOTAL REVENUES	741.0		710.6		2,071.7		2,154.0
Expenses
Purchased Electricity from AEP Affiliates	24.1		40.6		96.8		120.4
Amortization of Generation Deferrals	0.0		8.8		0.0		65.3
Other Operation	244.6		194.9		608.5		565.7
Maintenance	33.7		40.0		92.2		106.7
Depreciation and Amortization	74.1		57.4		204.4		176.8
Taxes Other Than Income Taxes	117.8		112.0		337.8		326.9
TOTAL EXPENSES	643.6		612.0		1,752.0		1,815.8
OPERATING INCOME (LOSS)	97.4		98.6		319.7		338.2
Other Income (Expense):
Interest Income	0.4		0.8		0.8		2.7
Carrying Costs Income	0.3		0.3		1.3		0.7
Allowance for Equity Funds Used During Construction	4.6		4.8		9.3		14.1
Non-Service Cost Components of Net Periodic Benefit Cost	3.8		3.7		11.3		11.0
Interest Expense	(29.4)		(27.9)		(88.4)		(78.1)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	77.1		80.3		254.0		288.6
Income Tax Expense (Benefit)	18.1		11.2		39.0		40.9
Net Income (Loss)	59.0		69.1		215.0		247.7
Ohio Power Co [Member] | Transmission and Distribution Utilities [Member]
Revenues
Revenue from Contracts with Customers	730.4		698.6		2,031.4		2,127.4
Ohio Power Co [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	2.3		3.0		7.3		8.4
TOTAL REVENUES	3.4	[5]	(2.8)	[6]	13.3	[7]	3.8	[8]
Ohio Power Co [Member] | Purchased Electricity for Resale [Member]
Expenses
Cost of Goods and Services Sold	149.3		158.3		412.3		454.0
Public Service Co Of Oklahoma [Member]
Revenues
Sales to AEP Affiliates	1.4		1.3		3.8		5.0
TOTAL REVENUES	382.2		493.0		988.1		1,173.9
Expenses
Other Operation	91.7		87.6		248.5		226.0
Maintenance	19.9		21.5		68.9		70.1
Depreciation and Amortization	40.1		39.1		129.8		125.4
Taxes Other Than Income Taxes	12.1		11.1		35.8		33.0
TOTAL EXPENSES	289.4		373.0		833.3		976.4
OPERATING INCOME (LOSS)	92.8		120.0		154.8		197.5
Other Income (Expense):
Interest Income	0.0		0.4		0.1		0.6
Allowance for Equity Funds Used During Construction	1.3		0.8		3.2		1.5
Non-Service Cost Components of Net Periodic Benefit Cost	2.1		2.1		6.3		6.3
Interest Expense	(14.6)		(16.1)		(45.9)		(50.3)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	81.6		107.2		118.5		155.6
Income Tax Expense (Benefit)	1.3		6.9		2.1		7.2
Net Income (Loss)	80.3		100.3		116.4		148.4
Public Service Co Of Oklahoma [Member] | Vertically Integrated Utilities [Member]
Revenues
Revenue from Contracts with Customers	379.8		490.5		976.3		1,164.3
Public Service Co Of Oklahoma [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	1.0		1.2		8.0		4.6
TOTAL REVENUES	0.0	[5]	0.0	[6]	0.0	[7]	0.0	[8]
Public Service Co Of Oklahoma [Member] | Fuel and Other Consumables Used for Electric Generation [Member]
Expenses
Cost of Goods and Services Sold	20.9		98.4		36.2		181.2
Public Service Co Of Oklahoma [Member] | Purchased Electricity for Resale [Member]
Expenses
Cost of Goods and Services Sold	104.7		115.3		314.1		340.7
Southwestern Electric Power Co [Member]
Revenues
Sales to AEP Affiliates	8.5		8.8		33.5		21.6
TOTAL REVENUES	517.3		545.5		1,318.2		1,342.1
Expenses
Other Operation	96.8		91.9		259.0		242.4
Maintenance	30.7		35.9		97.2		104.1
Depreciation and Amortization	68.5		63.2		203.9		187.1
Taxes Other Than Income Taxes	26.7		26.2		77.0		76.0
TOTAL EXPENSES	395.4		410.8		1,068.6		1,120.3
OPERATING INCOME (LOSS)	121.9		134.7		249.6		221.8
Other Income (Expense):
Interest Income	0.6		0.6		1.7		2.0
Allowance for Equity Funds Used During Construction	3.4		1.6		5.7		4.5
Non-Service Cost Components of Net Periodic Benefit Cost	2.1		2.1		6.3		6.4
Interest Expense	(29.3)		(29.2)		(89.1)		(89.4)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	98.7		109.8		174.2		145.3
Income Tax Expense (Benefit)	10.8		(0.7)		12.5		0.0
Equity Earnings (Loss) of Unconsolidated Subsidiaries	0.7		0.8		2.2		2.3
Net Income (Loss)	88.6		111.3		163.9		147.6
Net Income (Loss) Attributable to Noncontrolling Interests	0.7		0.8		2.1		3.1
Earnings Attributable to Common Shareholders	87.9		110.5		161.8		144.5
Earnings Per Share
Provision for Refund	2.4		(0.1)		(2.0)		(25.3)
Southwestern Electric Power Co [Member] | Vertically Integrated Utilities [Member]
Revenues
Revenue from Contracts with Customers	505.7		536.5		1,284.3		1,344.8
Southwestern Electric Power Co [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	0.7		0.3		2.4		1.0
TOTAL REVENUES	0.0	[5]	0.0	[6]	0.0	[7]	0.0	[8]
Southwestern Electric Power Co [Member] | Fuel and Other Consumables Used for Electric Generation [Member]
Expenses
Cost of Goods and Services Sold	131.7		148.8		306.4		400.2
Southwestern Electric Power Co [Member] | Purchased Electricity for Resale [Member]
Expenses
Cost of Goods and Services Sold	$ 41.0		$ 44.8		$ 125.1		$ 110.5

[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.

[7] Amounts include affiliated and nonaffiliated revenues.

[8] Amounts include affiliated and nonaffiliated revenues.