Consolidated Statements of Income - USD ($) $ in Millions	3 Months Ended				9 Months Ended
	Sep. 30, 2021		Sep. 30, 2020		Sep. 30, 2021		Sep. 30, 2020
Revenues
Revenue from Contracts with Customers	$ 4,623.0		$ 4,066.4		$ 12,730.6		$ 11,307.9
Sales to AEP Affiliates	0.0		0.0		0.0		0.0
TOTAL REVENUES	4,623.0		4,066.4		12,730.6		11,307.9
Expenses
Other Operation	735.3		702.9		1,894.6		1,871.0
Maintenance	277.8		237.6		817.0		730.5
Depreciation and Amortization	700.3		644.6		2,103.9		1,996.3
Taxes Other Than Income Taxes	360.8		337.7		1,061.4		976.3
TOTAL EXPENSES	3,515.6		3,123.2		10,003.0		8,890.4
OPERATING INCOME (LOSS)	1,107.4		943.2		2,727.6		2,417.5
Other Income (Expense):
Other Income	(20.6)		5.5		34.2		15.4
Allowance for Equity Funds Used During Construction	37.0		45.2		103.9		111.7
Non-Service Cost Components of Net Periodic Benefit Cost	29.6		29.7		88.9		89.2
Interest Expense	(303.7)		(291.3)		(895.5)		(877.4)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	849.7		732.3		2,059.1		1,756.4
Income Tax Expense (Benefit)	69.8		(1.2)		185.5		57.9
Equity Earnings (Loss) of Unconsolidated Subsidiaries	17.0		14.7		75.9		63.5
Net Income (Loss)	796.9		748.2		1,949.5		1,762.0
Net Income (Loss) Attributable to Noncontrolling Interests	0.9		(0.4)		0.3		(2.6)
Earnings Attributable to Common Shareholders	$ 796.0		$ 748.6		$ 1,949.2		$ 1,764.6
Earnings Per Share
Weighted Average Number of Basic AEP Common Shares Outstanding	501,233,680		496,177,968		499,418,278		495,479,190
Total Basic Earnings Per Share Attributable to AEP Common Shareholders	$ 1.59		$ 1.51		$ 3.90		$ 3.56
Weighted Average Number of Diluted AEP Common Shares Outstanding	502,606,836		497,458,523		500,600,237		496,916,187
Total Diluted Earnings Per Share Attributable to AEP Common Shareholders	$ 1.58		$ 1.50		$ 3.89		$ 3.55
Common Stock, Dividends Per Share, Declared	$ 0.74		$ 0.70
Vertically Integrated Utilities [Member]
Revenues
Revenue from Contracts with Customers	$ 2,716.8		$ 2,400.1		$ 7,445.9		$ 6,655.4
Transmission and Distribution Utilities [Member]
Revenues
Revenue from Contracts with Customers	1,195.0		1,124.1		3,366.9		3,208.7
Generation and Marketing [Member]
Revenues
Revenue from Contracts with Customers	617.4		464.8		1,641.6		1,223.4
Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	93.8		77.4		276.2		220.4
TOTAL REVENUES	154.8	[1]	(5.5)	[2]	188.7	[3]	13.3	[4]
Purchased Electricity, Fuel and Other Consumables Used for Electric Generation [Member]
Expenses
Cost of Goods and Services Sold	1,441.4		1,200.4		4,126.1		3,316.3
AEP Texas Inc. [Member]
Revenues
Sales to AEP Affiliates	0.9		41.4		2.9		89.4
TOTAL REVENUES	432.6		432.0		1,195.3		1,257.1
Expenses
Other Operation	135.3		134.3		367.1		344.7
Maintenance	22.0		20.4		59.8		64.1
Depreciation and Amortization	87.6		107.7		287.1		435.8
Taxes Other Than Income Taxes	41.6		38.7		117.4		106.7
TOTAL EXPENSES	286.5		311.5		831.4		964.9
OPERATING INCOME (LOSS)	146.1		120.5		363.9		292.2
Other Income (Expense):
Interest Income	0.2		0.5		0.6		1.2
Allowance for Equity Funds Used During Construction	9.2		4.4		16.7		14.4
Non-Service Cost Components of Net Periodic Benefit Cost	2.8		2.8		8.3		8.4
Interest Expense	(44.2)		(44.5)		(132.5)		(129.2)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	114.1		83.7		257.0		187.0
Income Tax Expense (Benefit)	14.6		1.1		31.6		(10.1)
Net Income (Loss)	99.5		82.6		225.4		197.1
AEP Texas Inc. [Member] | Transmission and Distribution Utilities [Member]
Revenues
Revenue from Contracts with Customers	430.8		390.1		1,189.1		1,165.2
AEP Texas Inc. [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	0.9		0.5		3.3		2.5
TOTAL REVENUES	0.0	[5]	40.6	[6]	0.0	[7]	86.9	[8]
AEP Texas Inc. [Member] | Fuel and Other Consumables Used for Electric Generation [Member]
Expenses
Cost of Goods and Services Sold	0.0		10.4		0.0		13.6
AEP Transmission Co [Member]
Revenues
Sales to AEP Affiliates	297.6		241.2		864.6		652.6
TOTAL REVENUES	377.0		304.1		1,104.2		837.8
Expenses
Other Operation	32.6		25.3		78.1		72.0
Maintenance	5.4		3.5		12.3		6.8
Depreciation and Amortization	76.0		61.5		219.0		176.4
Taxes Other Than Income Taxes	61.0		52.2		178.9		152.8
TOTAL EXPENSES	175.0		142.5		488.3		408.0
OPERATING INCOME (LOSS)	202.0		161.6		615.9		429.8
Other Income (Expense):
Interest Income	0.2		0.2		0.4		2.3
Allowance for Equity Funds Used During Construction	16.0		20.2		49.3		54.9
Interest Expense	(36.1)		(32.7)		(104.5)		(95.1)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	182.1		149.3		561.1		391.9
Income Tax Expense (Benefit)	36.7		31.7		115.4		82.8
Net Income (Loss)	145.4		117.6		445.7		309.1
AEP Transmission Co [Member] | Transmission [Member]
Revenues
Revenue from Contracts with Customers	79.2		62.9		239.3		184.6
AEP Transmission Co [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	0.2		0.0		0.3		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	52.4		44.4		140.6		124.9
TOTAL REVENUES	804.0		735.7		2,298.0		2,122.6
Expenses
Other Operation	173.0		136.3		442.1		379.1
Maintenance	69.1		52.0		184.4		148.7
Depreciation and Amortization	135.4		123.2		406.6		366.0
Taxes Other Than Income Taxes	39.8		38.8		116.7		114.2
TOTAL EXPENSES	670.5		583.8		1,870.1		1,679.4
OPERATING INCOME (LOSS)	133.5		151.9		427.9		443.2
Other Income (Expense):
Interest Income	0.2		0.6		0.8		1.4
Allowance for Equity Funds Used During Construction	4.3		6.7		12.1		11.5
Non-Service Cost Components of Net Periodic Benefit Cost	4.7		4.7		14.2		14.1
Interest Expense	(52.8)		(55.0)		(160.6)		(162.2)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	89.9		108.9		294.4		308.0
Income Tax Expense (Benefit)	3.6		(7.7)		19.3		(5.2)
Net Income (Loss)	86.3		116.6		275.1		313.2
Appalachian Power Co [Member] | Vertically Integrated Utilities [Member]
Revenues
Revenue from Contracts with Customers	748.5		688.9		2,149.2		1,989.9
Appalachian Power Co [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	3.1		2.4		8.2		7.8
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]
Expenses
Cost of Goods and Services Sold	170.8		166.0		471.9		430.9
Appalachian Power Co [Member] | Purchased Electricity for Resale [Member]
Expenses
Cost of Goods and Services Sold	82.4		67.5		248.4		240.5
Indiana Michigan Power Co [Member]
Revenues
Sales to AEP Affiliates	1.1		1.3		2.6		9.1
Other Revenues - Affiliated	14.7		14.1		41.2		42.4
TOTAL REVENUES	635.7		586.7		1,784.0		1,703.6
Expenses
Purchased Electricity from AEP Affiliates	63.3		55.9		172.7		135.8
Other Operation	167.5		165.5		482.4		459.7
Maintenance	52.0		51.0		165.4		144.4
Depreciation and Amortization	110.6		104.5		328.7		303.6
Taxes Other Than Income Taxes	27.8		27.4		83.8		79.5
TOTAL EXPENSES	509.8		486.2		1,494.8		1,397.1
OPERATING INCOME (LOSS)	125.9		100.5		289.2		306.5
Other Income (Expense):
Other Income	2.5		2.2		8.9		7.8
Allowance for Equity Funds Used During Construction					9.7		8.8
Non-Service Cost Components of Net Periodic Benefit Cost	4.1		4.1		12.3		12.5
Interest Expense	(30.2)		(26.9)		(86.6)		(85.7)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	102.3		79.9		223.8		241.1
Income Tax Expense (Benefit)	(1.8)		3.2		(8.3)		8.3
Net Income (Loss)	104.1		76.7		232.1		232.8
Indiana Michigan Power Co [Member] | Vertically Integrated Utilities [Member]
Revenues
Revenue from Contracts with Customers	618.2		570.1		1,735.1		1,648.4
Indiana Michigan Power Co [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	1.7		1.2		5.1		3.7
Sales to AEP Affiliates	17.0		15.0		46.0		49.0
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	43.7		44.4		129.9		146.0
Indiana Michigan Power Co [Member] | Purchased Electricity for Resale [Member]
Expenses
Cost of Goods and Services Sold	44.9		37.5		131.9		128.1
Ohio Power Co [Member]
Revenues
Sales to AEP Affiliates	4.3		8.3		21.9		33.0
TOTAL REVENUES	767.7		741.0		2,196.5		2,071.7
Expenses
Purchased Electricity from AEP Affiliates	3.5		24.1		48.0		96.8
Other Operation	245.1		244.6		622.9		608.5
Maintenance	39.3		33.7		116.4		92.2
Depreciation and Amortization	76.9		74.1		228.6		204.4
Taxes Other Than Income Taxes	126.0		117.8		366.2		337.8
TOTAL EXPENSES	675.5		643.6		1,895.7		1,752.0
OPERATING INCOME (LOSS)	92.2		97.4		300.8		319.7
Other Income (Expense):
Interest Income	0.2		0.4		0.5		0.8
Carrying Costs Income	0.1		0.3		1.1		1.3
Allowance for Equity Funds Used During Construction	2.0		4.6		7.6		9.3
Non-Service Cost Components of Net Periodic Benefit Cost	3.7		3.8		11.0		11.3
Interest Expense	(32.9)		(29.4)		(96.2)		(88.4)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	65.3		77.1		224.8		254.0
Income Tax Expense (Benefit)	8.9		18.1		26.2		39.0
Net Income (Loss)	56.4		59.0		198.6		215.0
Ohio Power Co [Member] | Transmission and Distribution Utilities [Member]
Revenues
Revenue from Contracts with Customers	761.0		730.4		2,167.8		2,031.4
Ohio Power Co [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	2.4		2.3		6.8		7.3
TOTAL REVENUES	4.9	[5]	3.4	[6]	14.2	[7]	13.3	[8]
Ohio Power Co [Member] | Purchased Electricity for Resale [Member]
Expenses
Cost of Goods and Services Sold	184.7		149.3		513.6		412.3
Public Service Co Of Oklahoma [Member]
Revenues
Sales to AEP Affiliates	1.0		1.4		3.1		3.8
TOTAL REVENUES	483.8		382.2		1,124.4		988.1
Expenses
Other Operation	102.3		91.7		262.7		248.5
Maintenance	21.2		19.9		68.1		68.9
Depreciation and Amortization	48.9		40.1		149.0		129.8
Taxes Other Than Income Taxes	12.1		12.1		37.1		35.8
TOTAL EXPENSES	380.4		289.4		957.7		833.3
OPERATING INCOME (LOSS)	103.4		92.8		166.7		154.8
Other Income (Expense):
Interest Income	1.3		0.0		3.0		0.1
Allowance for Equity Funds Used During Construction	0.5		1.3		1.5		3.2
Non-Service Cost Components of Net Periodic Benefit Cost	2.1		2.1		6.4		6.3
Interest Expense	(16.2)		(14.6)		(44.7)		(45.9)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	91.1		81.6		132.9		118.5
Income Tax Expense (Benefit)	(2.1)		1.3		(3.7)		2.1
Net Income (Loss)	93.2		80.3		136.6		116.4
Public Service Co Of Oklahoma [Member] | Vertically Integrated Utilities [Member]
Revenues
Revenue from Contracts with Customers	481.3		379.8		1,117.4		976.3
Public Service Co Of Oklahoma [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	1.5		1.0		3.9		8.0
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	195.9		125.6		440.8		350.3
Southwestern Electric Power Co [Member]
Revenues
Sales to AEP Affiliates	13.5		10.9		32.2		31.5
TOTAL REVENUES	584.1		517.3		1,630.3		1,318.2
Expenses
Other Operation	91.7		96.8		270.6		259.0
Maintenance	33.7		30.7		99.5		97.2
Depreciation and Amortization	74.8		68.5		217.4		203.9
Taxes Other Than Income Taxes	28.9		26.7		89.0		77.0
TOTAL EXPENSES	443.5		395.4		1,329.2		1,068.6
OPERATING INCOME (LOSS)	140.6		121.9		301.1		249.6
Other Income (Expense):
Interest Income	2.8		0.6		6.9		1.7
Allowance for Equity Funds Used During Construction	1.4		3.4		5.4		5.7
Non-Service Cost Components of Net Periodic Benefit Cost	2.1		2.1		6.2		6.3
Interest Expense	(31.7)		(29.3)		(92.4)		(89.1)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	115.2		98.7		227.2		174.2
Income Tax Expense (Benefit)	6.3		10.8		19.0		12.5
Equity Earnings (Loss) of Unconsolidated Subsidiaries	1.0		0.7		2.5		2.2
Net Income (Loss)	109.9		88.6		210.7		163.9
Net Income (Loss) Attributable to Noncontrolling Interests	1.0		0.7		2.6		2.1
Earnings Attributable to Common Shareholders	108.9		87.9		208.1		161.8
Southwestern Electric Power Co [Member] | Vertically Integrated Utilities [Member]
Revenues
Revenue from Contracts with Customers	570.1		505.7		1,596.6		1,284.3
Southwestern Electric Power Co [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	0.5		0.7		1.5		2.4
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	$ 214.4		$ 172.7		$ 652.7		$ 431.5

[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.