Consolidated Statements of Income - USD ($) $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2021		Jun. 30, 2020		Jun. 30, 2021		Jun. 30, 2020
Revenues
Revenue from Contracts with Customers	$ 3,826.5		$ 3,494.0		$ 8,107.6		$ 7,241.5
Sales to AEP Affiliates	0.0		0.0		0.0		0.0
TOTAL REVENUES	3,826.5		3,494.0		8,107.6		7,241.5
Expenses
Other Operation	566.9		566.0		1,159.3		1,168.1
Maintenance	264.3		243.4		539.2		492.9
Depreciation and Amortization	707.3		679.5		1,403.6		1,351.7
Taxes Other Than Income Taxes	354.1		317.5		700.6		638.6
TOTAL EXPENSES	3,016.6		2,771.3		6,487.4		5,767.2
OPERATING INCOME (LOSS)	809.9		722.7		1,620.2		1,474.3
Other Income (Expense):
Other Income	33.1		14.3		54.8		9.9
Allowance for Equity Funds Used During Construction	33.5		35.1		66.9		66.5
Non-Service Cost Components of Net Periodic Benefit Cost	29.7		29.8		59.3		59.5
Interest Expense	(301.6)		(294.0)		(591.8)		(586.1)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	604.6		507.9		1,209.4		1,024.1
Income Tax Expense (Benefit)	61.2		12.6		115.7		59.1
Equity Earnings (Loss) of Unconsolidated Subsidiaries	30.4		19.2		58.9		48.8
Net Income (Loss)	573.8		514.5		1,152.6		1,013.8
Net Income (Loss) Attributable to Noncontrolling Interests	(4.4)		(6.3)		(0.6)		(2.2)
Earnings Attributable to Common Shareholders	$ 578.2		$ 520.8		$ 1,153.2		$ 1,016.0
Earnings Per Share
Weighted Average Number of Basic AEP Common Shares Outstanding	499,916,640		495,655,053		498,495,532		495,125,961
Total Basic Earnings Per Share Attributable to AEP Common Shareholders	$ 1.16		$ 1.05		$ 2.31		$ 2.05
Weighted Average Number of Diluted AEP Common Shares Outstanding	500,983,778		497,337,980		499,581,893		496,973,449
Total Diluted Earnings Per Share Attributable to AEP Common Shareholders	$ 1.15		$ 1.05		$ 2.31		$ 2.04
Common Stock, Dividends Per Share, Declared	$ 0.74		$ 0.70
Vertically Integrated Utilities [Member]
Revenues
Revenue from Contracts with Customers	$ 2,224.6		$ 2,062.3		$ 4,729.1		$ 4,255.3
Transmission and Distribution Utilities [Member]
Revenues
Revenue from Contracts with Customers	1,089.6		1,009.4		2,171.9		2,084.6
Generation and Marketing [Member]
Revenues
Revenue from Contracts with Customers	422.5		350.2		1,024.2		758.6
Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	89.8		72.1		182.4		143.0
TOTAL REVENUES	29.1	[1]	(1.1)	[2]	33.9	[3]	18.8	[4]
Purchased Electricity, Fuel and Other Consumables Used for Electric Generation [Member]
Expenses
Cost of Goods and Services Sold	1,124.0		964.9		2,684.7		2,115.9
AEP Texas Inc. [Member]
Revenues
Sales to AEP Affiliates	1.0		16.9		2.0		48.0
TOTAL REVENUES	398.5		401.5		762.7		825.1
Expenses
Other Operation	109.6		92.9		231.8		210.4
Maintenance	18.7		23.1		37.8		43.7
Depreciation and Amortization	102.0		165.6		199.5		328.1
Taxes Other Than Income Taxes	39.5		34.0		75.8		68.0
TOTAL EXPENSES	269.8		318.8		544.9		653.4
OPERATING INCOME (LOSS)	128.7		82.7		217.8		171.7
Other Income (Expense):
Interest Income	0.2		0.1		0.4		0.7
Allowance for Equity Funds Used During Construction	3.4		4.9		7.5		10.0
Non-Service Cost Components of Net Periodic Benefit Cost	2.7		2.8		5.5		5.6
Interest Expense	(45.3)		(42.2)		(88.3)		(84.7)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	89.7		48.3		142.9		103.3
Income Tax Expense (Benefit)	9.9		(18.6)		17.0		(11.2)
Net Income (Loss)	79.8		66.9		125.9		114.5
AEP Texas Inc. [Member] | Transmission and Distribution Utilities [Member]
Revenues
Revenue from Contracts with Customers	396.6		383.5		758.3		775.1
AEP Texas Inc. [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	0.9		1.1		2.4		2.0
TOTAL REVENUES	0.0	[5]	16.1	[6]	0.0	[7]	46.3	[8]
AEP Texas Inc. [Member] | Fuel and Other Consumables Used for Electric Generation [Member]
Expenses
Cost of Goods and Services Sold	0.0		3.2		0.0		3.2
AEP Transmission Co [Member]
Revenues
Sales to AEP Affiliates	281.4		177.7		567.0		411.4
TOTAL REVENUES	365.5		238.1		727.2		533.7
Expenses
Other Operation	24.4		22.9		45.5		46.7
Maintenance	3.3		0.1		6.9		3.3
Depreciation and Amortization	72.4		58.9		143.0		114.9
Taxes Other Than Income Taxes	60.1		50.2		117.9		100.6
TOTAL EXPENSES	160.2		132.1		313.3		265.5
OPERATING INCOME (LOSS)	205.3		106.0		413.9		268.2
Other Income (Expense):
Interest Income	0.1		1.3		0.2		2.1
Allowance for Equity Funds Used During Construction	16.6		18.5		33.3		34.7
Interest Expense	(34.3)		(32.8)		(68.4)		(62.4)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	187.7		93.0		379.0		242.6
Income Tax Expense (Benefit)	39.1		19.3		78.7		51.1
Net Income (Loss)	148.6		73.7		300.3		191.5
AEP Transmission Co [Member] | Transmission [Member]
Revenues
Revenue from Contracts with Customers	84.1		60.4		160.1		121.7
AEP Transmission Co [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	0.0		0.0		0.1		0.6
TOTAL REVENUES	0.0	[5]	0.0	[6]	0.0	[7]	0.0	[8]
Appalachian Power Co [Member]
Revenues
Sales to AEP Affiliates	38.1		30.8		88.2		80.5
TOTAL REVENUES	677.0		637.5		1,494.0		1,386.9
Expenses
Other Operation	118.7		108.8		269.1		242.8
Maintenance	50.1		46.4		115.3		96.7
Depreciation and Amortization	135.4		120.6		271.2		242.8
Taxes Other Than Income Taxes	39.2		37.5		76.9		75.4
TOTAL EXPENSES	556.5		517.6		1,199.6		1,095.6
OPERATING INCOME (LOSS)	120.5		119.9		294.4		291.3
Other Income (Expense):
Interest Income	0.3		0.5		0.6		0.8
Allowance for Equity Funds Used During Construction	4.3		2.4		7.8		4.8
Non-Service Cost Components of Net Periodic Benefit Cost	4.8		4.7		9.5		9.4
Interest Expense	(52.9)		(54.1)		(107.8)		(107.2)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	77.0		73.4		204.5		199.1
Income Tax Expense (Benefit)	10.7		(7.9)		15.7		2.5
Net Income (Loss)	66.3		81.3		188.8		196.6
Appalachian Power Co [Member] | Vertically Integrated Utilities [Member]
Revenues
Revenue from Contracts with Customers	636.5		604.0		1,400.7		1,301.0
Appalachian Power Co [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	2.4		2.7		5.1		5.4
TOTAL REVENUES	(0.2)	[5]	0.0	[6]	0.0	[7]	0.0	[8]
Appalachian Power Co [Member] | Fuel and Other Consumables Used for Electric Generation [Member]
Expenses
Cost of Goods and Services Sold	137.2		153.9		301.1		264.9
Appalachian Power Co [Member] | Purchased Electricity for Resale [Member]
Expenses
Cost of Goods and Services Sold	75.9		50.4		166.0		173.0
Indiana Michigan Power Co [Member]
Revenues
Sales to AEP Affiliates	0.7		4.9		1.5		7.8
Other Revenues - Affiliated	12.2		15.8		26.5		28.3
TOTAL REVENUES	583.8		546.6		1,148.3		1,116.9
Expenses
Purchased Electricity from AEP Affiliates	57.8		43.7		109.4		79.9
Other Operation	160.3		149.5		314.9		294.2
Maintenance	64.4		44.3		113.4		93.4
Depreciation and Amortization	108.9		105.2		218.1		199.1
Taxes Other Than Income Taxes	29.8		25.7		56.0		52.1
TOTAL EXPENSES	510.8		457.3		985.0		910.9
OPERATING INCOME (LOSS)	73.0		89.3		163.3		206.0
Other Income (Expense):
Other Income	3.4		3.1		6.4		5.6
Allowance for Equity Funds Used During Construction					7.0		4.8
Non-Service Cost Components of Net Periodic Benefit Cost	4.1		4.2		8.2		8.4
Interest Expense	(29.1)		(28.1)		(56.4)		(58.8)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	51.4		68.5		121.5		161.2
Income Tax Expense (Benefit)	(5.8)		4.7		(6.5)		5.1
Net Income (Loss)	57.2		63.8		128.0		156.1
Indiana Michigan Power Co [Member] | Vertically Integrated Utilities [Member]
Revenues
Revenue from Contracts with Customers	569.2		524.9		1,116.9		1,078.3
Indiana Michigan Power Co [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	1.7		1.0		3.4		2.5
Sales to AEP Affiliates	13.0		18.0		29.0		34.0
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	49.9		48.4		86.2		101.6
Indiana Michigan Power Co [Member] | Purchased Electricity for Resale [Member]
Expenses
Cost of Goods and Services Sold	39.7		40.5		87.0		90.6
Ohio Power Co [Member]
Revenues
Sales to AEP Affiliates	12.8		16.3		17.6		24.7
TOTAL REVENUES	704.9		640.4		1,428.8		1,330.7
Expenses
Purchased Electricity from AEP Affiliates	14.4		30.3		44.5		72.7
Other Operation	193.2		186.6		377.8		363.9
Maintenance	38.4		26.9		77.1		58.5
Depreciation and Amortization	76.6		59.8		151.7		130.3
Taxes Other Than Income Taxes	118.9		108.0		240.2		220.0
TOTAL EXPENSES	595.1		525.5		1,220.2		1,108.4
OPERATING INCOME (LOSS)	109.8		114.9		208.6		222.3
Other Income (Expense):
Interest Income	0.1		0.2		0.3		0.4
Carrying Costs Income	0.5		0.6		1.0		1.0
Allowance for Equity Funds Used During Construction	2.9		2.8		5.6		4.7
Non-Service Cost Components of Net Periodic Benefit Cost	3.6		3.7		7.3		7.5
Interest Expense	(31.7)		(30.1)		(63.3)		(59.0)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	85.2		92.1		159.5		176.9
Income Tax Expense (Benefit)	11.2		11.2		17.3		20.9
Net Income (Loss)	74.0		80.9		142.2		156.0
Ohio Power Co [Member] | Transmission and Distribution Utilities [Member]
Revenues
Revenue from Contracts with Customers	690.1		621.8		1,406.8		1,301.0
Ohio Power Co [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	2.0		2.3		4.4		5.0
TOTAL REVENUES	4.0	[5]	3.8	[6]	9.3	[7]	9.9	[8]
Ohio Power Co [Member] | Purchased Electricity for Resale [Member]
Expenses
Cost of Goods and Services Sold	153.6		113.9		328.9		263.0
Public Service Co Of Oklahoma [Member]
Revenues
Sales to AEP Affiliates	1.1		1.3		2.1		2.4
TOTAL REVENUES	344.5		308.6		640.6		605.9
Expenses
Other Operation	81.3		69.6		160.4		156.8
Maintenance	22.5		24.6		46.9		49.0
Depreciation and Amortization	50.2		45.0		100.1		89.7
Taxes Other Than Income Taxes	12.5		12.4		25.0		23.7
TOTAL EXPENSES	290.5		249.0		577.3		543.9
OPERATING INCOME (LOSS)	54.0		59.6		63.3		62.0
Other Income (Expense):
Interest Income	1.6		0.0		1.7		0.1
Allowance for Equity Funds Used During Construction	0.6		0.9		1.0		1.9
Non-Service Cost Components of Net Periodic Benefit Cost	2.2		2.1		4.3		4.2
Interest Expense	(14.1)		(15.5)		(28.5)		(31.3)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	44.3		47.1		41.8		36.9
Income Tax Expense (Benefit)	(1.8)		0.7		(1.6)		0.8
Net Income (Loss)	46.1		46.4		43.4		36.1
Public Service Co Of Oklahoma [Member] | Vertically Integrated Utilities [Member]
Revenues
Revenue from Contracts with Customers	342.5		301.1		636.1		596.5
Public Service Co Of Oklahoma [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	0.9		6.2		2.4		7.0
TOTAL REVENUES	0.0	[5]	0.0	[6]	0.0	[7]	0.0	[8]
Public Service Co Of Oklahoma [Member] | Purchased Electricity, Fuel and Other Consumables Used for Electric Generation [Member]
Expenses
Cost of Goods and Services Sold	124.0		97.4		244.9		224.7
Southwestern Electric Power Co [Member]
Revenues
Sales to AEP Affiliates	10.9		13.1		18.7		20.6
TOTAL REVENUES	430.1		415.0		1,046.2		800.9
Expenses
Other Operation	88.6		70.0		178.9		162.2
Maintenance	31.8		32.7		65.8		66.5
Depreciation and Amortization	73.0		68.1		142.6		135.4
Taxes Other Than Income Taxes	30.1		25.0		60.1		50.3
TOTAL EXPENSES	362.0		322.4		885.7		673.2
OPERATING INCOME (LOSS)	68.1		92.6		160.5		127.7
Other Income (Expense):
Interest Income	3.1		0.5		4.1		1.1
Allowance for Equity Funds Used During Construction	1.9		0.9		4.0		2.3
Non-Service Cost Components of Net Periodic Benefit Cost	2.0		2.1		4.1		4.2
Interest Expense	(31.4)		(29.7)		(60.7)		(59.8)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	43.7		66.4		112.0		75.5
Income Tax Expense (Benefit)	7.1		7.9		12.7		1.7
Equity Earnings (Loss) of Unconsolidated Subsidiaries	0.8		0.7		1.5		1.5
Net Income (Loss)	37.4		59.2		100.8		75.3
Net Income (Loss) Attributable to Noncontrolling Interests	0.6		0.4		1.6		1.4
Earnings Attributable to Common Shareholders	36.8		58.8		99.2		73.9
Southwestern Electric Power Co [Member] | Vertically Integrated Utilities [Member]
Revenues
Revenue from Contracts with Customers	418.8		401.0		1,026.5		778.6
Southwestern Electric Power Co [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	0.4		0.9		1.0		1.7
TOTAL REVENUES	0.0	[5]	0.0	[6]	0.0	[7]	0.0	[8]
Southwestern Electric Power Co [Member] | Purchased Electricity, Fuel and Other Consumables Used for Electric Generation [Member]
Expenses
Cost of Goods and Services Sold	$ 138.5		$ 126.6		$ 438.3		$ 258.8

[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.