Business Segments (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2023		Dec. 31, 2022		Dec. 31, 2021
Reportable Segment Information
Revenue from Contract with Customers		$ 18,982.3		$ 19,639.5		$ 16,792.0
Total Revenues		18,982.3		19,639.5		16,792.0
Loss on the Expected Sale of KPCo				363.3
Asset Impairments and Other Related Charges		85.6		48.8		11.6
Establishment of 2017-2019 Virginia Triennial Review Regulatory Asset		0.0		(37.0)		0.0
Loss on the Sale of the Competitive Contracted Renewables Portfolio		92.7
Gain (Loss) on Disposition Assets				(116.3)
Depreciation and Amortization		3,090.4		3,202.8		2,825.7
Allowance for Equity Funds Used During Construction		174.9		133.7		139.7
Interest Expense		1,806.9		1,396.1		1,199.1
Income Tax Expense (Benefit)		54.6		5.4		115.5
Equity Earnings (Loss) of Unconsolidated Subsidiaries		58.5		(109.4)		91.7
Net Income (Loss)		2,212.6		2,305.6		2,488.1
Gross Property Additions		7,533.5		7,879.0		6,426.8
Balance Sheet Information
Property, Plant and Equipment, Gross, Period Increase (Decrease)		101,246.4		97,021.4
Accumulated Depreciation and Amortization		24,553.0		23,682.3
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		76,693.4		73,339.1
Total Assets		96,684.0		93,403.3
Investments in Equity Method Investees		1,073.6		1,276.7		1,447.5
Long-term Debt Due Within One Year		2,490.5		2,486.4
Long-term Debt		37,652.7		34,314.6
Total Long-term Debt Outstanding		40,143.2		36,801.0
Related Party
Reportable Segment Information
Revenue from Contract with Customers		0.0		0.0		0.0
AEP Transmission Co [Member]
Reportable Segment Information
Revenue from Contract with Customers		1,720.6		1,651.7		1,410.9
Total Revenues		1,672.0		1,624.5		1,469.3
Depreciation and Amortization		393.8		346.2		297.3
Interest Income		7.0		1.6		0.5
Allowance for Equity Funds Used During Construction		83.2		70.7		67.2
Interest Expense		194.5		162.7		141.2
Income Tax Expense (Benefit)		147.1		169.1		144.1
Net Income (Loss)		614.2		594.2		591.7
Gross Property Additions		1,503.1		1,468.3		1,442.7
Balance Sheet Information
Property, Plant and Equipment, Gross, Period Increase (Decrease)		15,789.0		14,366.9
Accumulated Depreciation and Amortization		1,291.3		1,027.0
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		14,497.7		13,339.9
Total Assets		15,072.5		13,814.2
Long-term Debt Due Within One Year		95.0		60.0
Long-term Debt		5,319.4		4,722.8
Total Long-term Debt Outstanding		5,414.4		4,782.8
AEP Transmission Co [Member] | Related Party
Reportable Segment Information
Revenue from Contract with Customers		1,463.4		1,354.5		1,171.5
Transmission Revenues		1,317.8		1,283.8		1,153.9
Vertically Integrated Utilities [Member]
Reportable Segment Information
Revenue from Contract with Customers		11,303.7		11,292.8		9,852.2
Transmission and Distribution Utilities Revenues [Member]
Reportable Segment Information
Revenue from Contract with Customers		5,677.2		5,489.6		4,464.1
Transmission [Member] | AEP Transmission Co [Member]
Reportable Segment Information
Revenue from Contract with Customers		363.3		354.9		317.8
Transmission Revenues		354.2		340.9		315.1
Generation and Marketing Revenues [Member]
Reportable Segment Information
Revenue from Contract with Customers		1,543.3		2,448.9		2,108.3
Other Revenues [Member]
Reportable Segment Information
Revenue from Contract with Customers		458.1		408.2		367.4
Total Revenues		(355.4)	[1],[2]	360.3	[3],[4]	227.6	[5],[6]
Other Revenues [Member] | AEP Transmission Co [Member]
Reportable Segment Information
Revenue from Contract with Customers				(0.2)		0.3
Total Revenues		0.0	[7]	0.0	[8]	0.0	[9]
Reconciling Adjustments [Member]
Reportable Segment Information
Revenue from Contract with Customers		0.0		0.0		0.0
Total Revenues		(1,709.2)		(1,603.8)		(1,461.5)
Loss on the Expected Sale of KPCo				0.0
Asset Impairments and Other Related Charges		0.0		0.0		0.0
Establishment of 2017-2019 Virginia Triennial Review Regulatory Asset				0.0
Loss on the Sale of the Competitive Contracted Renewables Portfolio		0.0
Gain (Loss) on Disposition Assets				0.0
Depreciation and Amortization		0.0		0.0		0.0
Interest Expense		(194.5)		(112.8)		(18.7)
Income Tax Expense (Benefit)		0.0		0.0		0.0
Equity Earnings (Loss) of Unconsolidated Subsidiaries		0.0		0.0		0.0
Net Income (Loss)		0.0		0.0		0.0
Gross Property Additions		1.4		(28.8)		(29.2)
Balance Sheet Information
Total Assets	[10]	(4,324.6)		(5,783.0)
Investments in Equity Method Investees		0.0		0.0		0.0
Reconciling Adjustments [Member] | Related Party
Reportable Segment Information
Revenue from Contract with Customers	[11]	(1,709.2)		(1,603.8)		(1,461.5)
Reconciling Adjustments [Member] | AEP Transmission Co [Member]
Reportable Segment Information
Total Revenues		0.0		0.0		0.0
Depreciation and Amortization		0.0		0.0		0.0
Interest Income	[12]	(214.8)		(176.9)		(157.7)
Allowance for Equity Funds Used During Construction		0.0		0.0		0.0
Interest Expense	[12]	(214.8)		(176.9)		(157.7)
Income Tax Expense (Benefit)		0.0		0.0		0.0
Net Income (Loss)		0.0		0.0		0.0
Gross Property Additions		0.0		0.0		0.0
Transmission Revenues		0.0		0.0		0.0
Balance Sheet Information
Total Assets	[13]	(5,534.7)		(4,878.8)
Reconciling Adjustments [Member] | AEP Transmission Co [Member] | Related Party
Reportable Segment Information
Transmission Revenues		0.0		0.0		0.0
Reconciling Adjustments [Member] | Other Revenues [Member]
Reportable Segment Information
Total Revenues		(15.3)	[1],[2]	(9.1)	[3],[4]	(10.7)	[5],[6]
Reconciling Adjustments [Member] | Other Revenues [Member] | AEP Transmission Co [Member]
Reportable Segment Information
Revenue from Contract with Customers				0.0		0.0
Vertically Integrated Utilities [Member]
Reportable Segment Information
Total Revenues		11,449.5		11,477.5		9,998.5
Loss on the Expected Sale of KPCo				0.0
Asset Impairments and Other Related Charges		85.6		24.9		11.6
Establishment of 2017-2019 Virginia Triennial Review Regulatory Asset				(37.0)
Loss on the Sale of the Competitive Contracted Renewables Portfolio		0.0
Gain (Loss) on Disposition Assets				0.0
Depreciation and Amortization		1,876.4		2,007.2		1,747.6
Interest Expense		764.5		650.9		574.2
Income Tax Expense (Benefit)		(45.2)		(93.8)		(11.2)
Equity Earnings (Loss) of Unconsolidated Subsidiaries		1.4		1.4		3.4
Net Income (Loss)		1,093.9		1,296.2		1,116.7
Gross Property Additions		3,486.8		4,164.6		2,963.1
Balance Sheet Information
Total Assets		51,802.1		49,761.8
Investments in Equity Method Investees		10.0		10.1		33.5
Vertically Integrated Utilities [Member] | Related Party
Reportable Segment Information
Revenue from Contract with Customers		145.8		184.7		146.3
Vertically Integrated Utilities [Member] | Vertically Integrated Utilities [Member]
Reportable Segment Information
Revenue from Contract with Customers		11,303.7		11,292.8		9,852.2
Vertically Integrated Utilities [Member] | Other Revenues [Member]
Reportable Segment Information
Total Revenues		24.6	[1],[2]	0.4	[3],[4]	(0.5)	[5],[6]
Transmission and Distribution Companies [Member]
Reportable Segment Information
Total Revenues		5,713.3		5,512.0		4,492.9
Loss on the Expected Sale of KPCo				0.0
Asset Impairments and Other Related Charges		0.0		0.0		0.0
Establishment of 2017-2019 Virginia Triennial Review Regulatory Asset				0.0
Loss on the Sale of the Competitive Contracted Renewables Portfolio		0.0
Gain (Loss) on Disposition Assets				0.0
Depreciation and Amortization		784.7		746.7		690.3
Interest Expense		363.6		328.0		300.9
Income Tax Expense (Benefit)		140.2		116.9		77.5
Equity Earnings (Loss) of Unconsolidated Subsidiaries		0.0		0.6		0.0
Net Income (Loss)		698.7		595.7		543.4
Gross Property Additions		2,467.4		2,177.3		1,766.0
Balance Sheet Information
Total Assets		24,838.4		22,920.2
Investments in Equity Method Investees		3.0		3.0		2.5
Transmission and Distribution Companies [Member] | Related Party
Reportable Segment Information
Revenue from Contract with Customers		36.1		22.4		28.8
Transmission and Distribution Companies [Member] | Transmission and Distribution Utilities Revenues [Member]
Reportable Segment Information
Revenue from Contract with Customers		5,677.2		5,489.6		4,464.1
Transmission and Distribution Companies [Member] | Other Revenues [Member]
Reportable Segment Information
Total Revenues		24.0	[1],[2]	18.6	[3],[4]	19.0	[5],[6]
AEP Transmission Holdco
Reportable Segment Information
Total Revenues		1,728.5		1,677.0		1,526.2
Loss on the Expected Sale of KPCo				0.0
Asset Impairments and Other Related Charges		0.0		0.0		0.0
Establishment of 2017-2019 Virginia Triennial Review Regulatory Asset				0.0
Loss on the Sale of the Competitive Contracted Renewables Portfolio		0.0
Gain (Loss) on Disposition Assets				0.0
Depreciation and Amortization		402.6		355.0		306.0
Interest Expense		202.6		169.3		146.3
Income Tax Expense (Benefit)		166.0		193.6		159.6
Equity Earnings (Loss) of Unconsolidated Subsidiaries		82.9		83.4		75.0
Net Income (Loss)		706.7		676.8		682.0
Gross Property Additions		1,528.7		1,470.8		1,468.6
Balance Sheet Information
Total Assets		16,575.6		15,215.8
Investments in Equity Method Investees		905.8		858.3		830.4
AEP Transmission Holdco | Related Party
Reportable Segment Information
Revenue from Contract with Customers		1,331.1		1,319.5		1,175.1
AEP Transmission Holdco | Transmission [Member]
Reportable Segment Information
Revenue from Contract with Customers		397.4		357.5		351.1
Generation and Marketing [Member]
Reportable Segment Information
Total Revenues		1,632.2		2,466.9		2,163.7
Loss on the Expected Sale of KPCo				0.0
Asset Impairments and Other Related Charges		0.0		0.0		0.0
Establishment of 2017-2019 Virginia Triennial Review Regulatory Asset				0.0
Loss on the Sale of the Competitive Contracted Renewables Portfolio		92.7
Gain (Loss) on Disposition Assets				(116.3)
Depreciation and Amortization		42.7		93.0		80.9
Interest Expense		76.0		51.8		15.6
Income Tax Expense (Benefit)		(122.9)		(83.1)		(48.8)
Equity Earnings (Loss) of Unconsolidated Subsidiaries		(16.5)		(192.4)		(10.6)
Net Income (Loss)		(29.1)		274.5		210.2
Gross Property Additions		12.6		69.2		232.8
Balance Sheet Information
Total Assets		2,598.5		4,520.1
Investments in Equity Method Investees		100.6		337.6		487.8
Generation and Marketing [Member] | Related Party
Reportable Segment Information
Revenue from Contract with Customers		88.9		18.0		55.4
Generation and Marketing [Member] | Generation and Marketing Revenues [Member]
Reportable Segment Information
Revenue from Contract with Customers		1,543.3		2,448.9		2,108.3
Generation and Marketing [Member] | Other Revenues [Member]
Reportable Segment Information
Total Revenues		(404.5)	[1],[2]	341.3	[3],[4]	209.1	[5],[6]
Other Segments [Member]
Reportable Segment Information
Total Revenues	[14]	168.0		109.9		72.2
Loss on the Expected Sale of KPCo	[14]			363.3
Asset Impairments and Other Related Charges	[14]	0.0		23.9		0.0
Establishment of 2017-2019 Virginia Triennial Review Regulatory Asset	[14]			0.0
Loss on the Sale of the Competitive Contracted Renewables Portfolio	[14]	0.0
Gain (Loss) on Disposition Assets	[14]			0.0
Depreciation and Amortization	[14]	(16.0)		0.9		0.9
Interest Expense	[14]	594.7		308.9		180.8
Income Tax Expense (Benefit)	[14]	(83.5)		(128.2)		(61.6)
Equity Earnings (Loss) of Unconsolidated Subsidiaries	[14]	(9.3)		(2.4)		23.9
Net Income (Loss)	[14]	(257.6)		(537.6)		(64.2)
Gross Property Additions	[14]	36.6		25.9		25.5
Balance Sheet Information
Total Assets	[14],[15]	5,194.0		6,768.4
Investments in Equity Method Investees	[14]	54.2		67.7		93.3
Other Segments [Member] | Related Party
Reportable Segment Information
Revenue from Contract with Customers	[14]	107.3		59.2		55.9
Other Segments [Member] | Other Revenues [Member]
Reportable Segment Information
Revenue from Contract with Customers	[14]	60.7		50.7		16.3
State Transcos [Member] | AEP Transmission Co [Member]
Reportable Segment Information
Total Revenues		1,672.0		1,624.5		1,469.3
Depreciation and Amortization		393.8		346.2		297.3
Interest Income		3.8		0.7		0.1
Allowance for Equity Funds Used During Construction		83.2		70.7		67.2
Interest Expense		194.2		162.5		141.2
Income Tax Expense (Benefit)		145.7		169.1		144.1
Net Income (Loss)		612.9		594.2		591.5
Gross Property Additions		1,503.1		1,468.3		1,442.7
Balance Sheet Information
Total Assets		15,120.6		13,875.6
State Transcos [Member] | AEP Transmission Co [Member] | Related Party
Reportable Segment Information
Transmission Revenues		1,317.8		1,283.8		1,153.9
State Transcos [Member] | Transmission [Member] | AEP Transmission Co [Member]
Reportable Segment Information
Transmission Revenues		354.2		340.9		315.1
State Transcos [Member] | Other Revenues [Member] | AEP Transmission Co [Member]
Reportable Segment Information
Revenue from Contract with Customers				(0.2)		0.3
AEPTCo Parent [Member] | AEP Transmission Co [Member]
Reportable Segment Information
Total Revenues		0.0		0.0		0.0
Depreciation and Amortization		0.0		0.0		0.0
Interest Income		218.0		177.8		158.1
Allowance for Equity Funds Used During Construction		0.0		0.0		0.0
Interest Expense		215.1		177.1		157.7
Income Tax Expense (Benefit)		1.4		0.0		0.0
Net Income (Loss)	[16]	1.3		0.0		0.2
Gross Property Additions		0.0		0.0		0.0
Balance Sheet Information
Total Assets	[17]	5,486.6		4,817.4
AEPTCo Parent [Member] | AEP Transmission Co [Member] | Related Party
Reportable Segment Information
Transmission Revenues		0.0		0.0		0.0
AEPTCo Parent [Member] | Transmission [Member] | AEP Transmission Co [Member]
Reportable Segment Information
Transmission Revenues		$ 0.0		0.0		0.0
AEPTCo Parent [Member] | Other Revenues [Member] | AEP Transmission Co [Member]
Reportable Segment Information
Revenue from Contract with Customers				$ 0.0		$ 0.0

[1] Amounts include affiliated and nonaffiliated revenues.

[2] Generation & Marketing includes economic hedge activity.

[3] Amounts include affiliated and nonaffiliated revenues.

[4] Generation & Marketing includes economic hedge activity.

[5] Amounts include affiliated and nonaffiliated revenues.

[6] Generation & Marketing includes economic hedge activity.

[7] Amounts include affiliated and nonaffiliated revenues.

[8] Amounts include affiliated and nonaffiliated revenues.

[9] Amounts include affiliated and nonaffiliated revenues.

[10] Reconciling Adjustments for Total Assets primarily include elimination of intercompany advances to affiliates and intercompany accounts receivable.

[11] Represents inter-segment revenues.

[12] Elimination of intercompany interest income/interest expense on affiliated debt arrangement.

[13] Primarily relates to elimination of Notes Receivable from the State Transcos.

[14] Corporate and Other primarily includes the purchasing of receivables from certain AEP utility subsidiaries. This segment also includes Parent’s guarantee revenue received from affiliates, investment income, interest income, interest expense and other nonallocated costs.

[15] Includes elimination of AEP Parent’s investments in wholly-owned subsidiary companies.

[16] Includes elimination of AEPTCo Parent’s equity earnings in the State Transcos.

[17] Primarily relates to Notes Receivable from the State Transcos.