Financing Activities (Details) - USD ($)		1 Months Ended		12 Months Ended
		Feb. 25, 2021	Jan. 31, 2021	Dec. 31, 2020		Dec. 31, 2019		Dec. 31, 2018
Shares of Company
Beginning Balance, Shares			516,808,354	514,373,631		513,450,036		512,210,644
Issued				2,434,723		923,595		1,239,392
Ending Balance, Shares				516,808,354		514,373,631		513,450,036
Treasury Stock, Shares, Beginning Balance			20,204,160	20,204,160		20,204,160		20,205,046
Partners' Capital Account, Units, Treasury Units Reissued	[1]							(886)
Treasury Stock, Shares, Ending Balance				20,204,160		20,204,160		20,204,160
Long-term Debt
Senior Unsecured Notes				$ 25,116,100,000		$ 21,180,700,000
Pollution Control Bonds	[2]			1,936,700,000		1,998,800,000
Notes Payable	[3]			239,100,000		234,300,000
Securitization Bonds				716,400,000		1,025,100,000
Spent Nuclear Fuel Obligation	[4]			281,200,000		279,800,000
Junior Subordinated Notes	[5]			1,624,100,000		787,800,000
Other Long-term Debt				1,158,900,000		1,219,000,000.0
Total Long-term Debt Outstanding				31,072,500,000		26,725,500,000
Outstanding Long-term Debt
Principal Amount, 2021				2,086,100,000
Principal Amount, 2022	[6]			3,538,400,000
Principal Amount, 2023	[7]			2,659,300,000
Principal Amount, 2024				723,400,000
Principal Amount, 2025				1,726,300,000
Principal Amount, After 2025				20,599,200,000
Principal Amount, Total				31,332,700,000
Unamortized Discount, Net and Debt Issuance Costs				(260,200,000)
Total Long-term Debt Outstanding				31,072,500,000		26,725,500,000
Short-term Debt
Securitized Debt for Receivables	[8]			592,000,000.0		710,000,000.0
Commercial Paper				1,852,300,000		2,110,000,000.0
Notes Payable				35,000,000.0		18,300,000
Total Short-term Debt				$ 2,479,300,000		$ 2,838,300,000
Securitized Debt for Receivables	[8],[9]			0.85%		2.42%
Comparative Accounts Receivable Information
Effective Interest Rates on Securitization of Accounts Receivable				0.85%		2.42%		2.16%
Net Uncollectible Accounts Receivable Written Off				$ 15,300,000		$ 26,600,000		$ 27,600,000
Customer Accounts Receivable Managed Portfolio
Accounts Receivable Retained Interest and Pledged as Collateral Less Uncollectible Accounts				958,400,000		841,800,000
Total Principal Outstanding				592,000,000.0		710,000,000.0
Delinquent Securitized Accounts Receivable				62,300,000		39,600,000
Bad Debt Reserves Related to Securitized Sale of Accounts Receivable				60,000,000.0		32,100,000
Unbilled Receivables Related to Securitization, Sale of Accounts Receivable				296,800,000		266,800,000
Fees Paid to AEP Credit for Customer Accounts Receivable Sold
Revenue from Contracts with Customers				14,918,500,000		15,561,400,000		16,195,700,000
Financing Activities (Textuals)
Repayments of Long-term Debt				1,339,800,000		1,220,800,000		2,782,000,000.0
Proceeds from Issuance of Long-term Debt				5,626,100,000		4,536,600,000		4,945,700,000
Forward Equity Purchase Contract included in Current and Noncurrent liabilities				$ (86,200,000)		(7,600,000)		23,100,000
Maximum Percentage Debt to Capitalization				67.50%
Restricted Net Assets				$ 14,000,000,000
Dividend Restrictions	[10]			2,369,500,000
Retained Earnings Available to Pay Dividends				7,100,000,000
Dividends Paid on Common Stock				(1,424,900,000)		$ (1,350,000,000.0)		(1,255,500,000)
Credit Facilities, Total				$ 4,000,000,000
Weighted Average Interest Rate of Commercial Paper Outstanding During Year				1.28%
Maximum Amount of Commercial Paper Outstanding				$ 3,000,000,000
Total Commitment From Bank Conduits To Finance Receivables				750,000,000
Maximum Value of Shares to be Issued Under ATM Program				$ 1,000,000,000
Maximum Percentage Paid to Selling Agents				2.00%
2019 Equity Units [Member]
Financing Activities (Textuals)
Equity Units Issued						16,100,000
Per Unit Conversion for Equity Units				$ 50
Net Equity Units Issuance Proceeds						$ 785,000,000
Principal Amounts of Junior Subordinated Debt				$ 1,000
Forward Equity Purchase Contract Date				2022
Equity Units Annual Distribution Rate				6.125%
Forward Equity Contract Payment Rate				2.725%
Maximum Shares Issued Under Equity Units Conversion				9,701,860
Corporate unit ownership share of an equity unit				5.00%
2020 Equity Units [Member]
Financing Activities (Textuals)
Equity Units Issued				17,000,000
Per Unit Conversion for Equity Units				$ 50
Net Equity Units Issuance Proceeds				833,000,000
Principal Amounts of Junior Subordinated Debt				$ 1,000
Forward Equity Purchase Contract Date				2023
Equity Units Annual Distribution Rate				6.125%
Forward Equity Contract Payment Rate				4.825%
Maximum Shares Issued Under Equity Units Conversion				10,205,100
Corporate unit ownership share of an equity unit				5.00%
Minimum [Member] | 2019 Equity Units [Member]
Financing Activities (Textuals)
AEP Share Price for Equity Unit Conversion				$ 82.98
Shares Per Equity Unit				0.5021
Minimum [Member] | 2020 Equity Units [Member]
Financing Activities (Textuals)
AEP Share Price for Equity Unit Conversion				$ 83.29
Shares Per Equity Unit				0.5003
Maximum [Member] | 2019 Equity Units [Member]
Financing Activities (Textuals)
AEP Share Price for Equity Unit Conversion				$ 99.58
Shares Per Equity Unit				0.6026
Maximum [Member] | 2020 Equity Units [Member]
Financing Activities (Textuals)
AEP Share Price for Equity Unit Conversion				$ 99.95
Shares Per Equity Unit				0.6003
Commercial Paper [Member]
Short-term Debt
Debt, Weighted Average Interest Rate	[9]			0.29%		2.10%
Loans Payable [Member]
Short-term Debt
Debt, Weighted Average Interest Rate	[9]			2.55%		3.29%
AEP Texas Inc. [Member]
Long-term Debt
Senior Unsecured Notes				$ 3,687,600,000		$ 3,090,900,000
Pollution Control Bonds				439,700,000		490,300,000
Securitization Bonds				492,600,000		776,800,000
Other Long-term Debt				200,500,000		200,400,000
Total Long-term Debt Outstanding				4,820,400,000		4,558,400,000
Outstanding Long-term Debt
Principal Amount, 2021				88,700,000
Principal Amount, 2022				716,000,000.0
Principal Amount, 2023				278,500,000
Principal Amount, 2024				96,000,000.0
Principal Amount, 2025				324,500,000
Principal Amount, After 2025				3,357,000,000.0
Principal Amount, Total				4,860,700,000
Unamortized Discount, Net and Debt Issuance Costs				(40,300,000)
Total Long-term Debt Outstanding				4,820,400,000		4,558,400,000
Fees Paid to AEP Credit for Customer Accounts Receivable Sold
Revenue from Contracts with Customers				1,528,000,000.0		1,551,600,000		1,493,000,000.0
Financing Activities (Textuals)
Repayments of Long-term Debt				392,100,000		401,800,000		266,100,000
Proceeds from Issuance of Long-term Debt				$ 652,700,000		1,070,400,000		$ 494,000,000.0
Maximum Percentage Debt to Capitalization				67.50%
Dividend Restrictions				$ 694,000,000.0
AEP Texas Inc. [Member] | Utility [Member]
Money Pool Participants' Money Pool Activity and Authorized Borrowing Limits
Maximum Borrowings from Money Pool				320,400,000		390,700,000
Maximum Loans to Money Pool				313,400,000		213,100,000
Average Borrowings from Money Pool				132,000,000.0		239,300,000
Average Loans to Money Pool				139,000,000.0		194,400,000
Net Loans (Borrowings) to/from Money Pool				(67,100,000)		199,700,000
Authorized Short Term Borrowing Limit				$ 500,000,000.0		$ 500,000,000.0
Maximum and Minimum Interest Rates
Maximum Interest Rate				2.70%		3.43%		2.97%
Minimum Interest Rate				0.27%		1.77%		1.81%
Average Interest Rates for Funds Borrowed from and Loaned to Money Pool
Average Interest Rate For Funds Borrowed				1.51%		2.63%		2.26%
Average Interest Rate For Funds Loaned				0.81%		2.03%		2.29%
AEP Texas Inc. [Member] | Nonutility [Member]
Maximum Interest Rate For Funds Loaned				2.70%		3.02%		2.97%
Minimum Interest Rate for Funds Loaned				0.27%		1.91%		1.83%
Money Pool Participants' Money Pool Activity and Authorized Borrowing Limits
Maximum Loans to Money Pool				$ 7,500,000		$ 8,000,000.0
Average Loans to Money Pool				7,100,000		7,700,000
Net Loans (Borrowings) to/from Money Pool				$ 7,100,000		$ 7,500,000
Average Interest Rates for Funds Borrowed from and Loaned to Money Pool
Average Interest Rate For Funds Loaned				1.18%		2.56%		2.36%
AEP Transmission Co [Member]
Long-term Debt
Senior Unsecured Notes				$ 3,948,500,000		$ 3,427,300,000
Total Long-term Debt Outstanding				3,948,500,000		3,427,300,000
Outstanding Long-term Debt
Principal Amount, 2021				50,000,000.0
Principal Amount, 2022				104,000,000.0
Principal Amount, 2023				60,000,000.0
Principal Amount, 2024				95,000,000.0
Principal Amount, 2025				90,000,000.0
Principal Amount, After 2025				3,591,000,000.0
Principal Amount, Total				3,990,000,000.0
Unamortized Discount, Net and Debt Issuance Costs				(41,500,000)
Total Long-term Debt Outstanding				3,948,500,000		3,427,300,000
Fees Paid to AEP Credit for Customer Accounts Receivable Sold
Revenue from Contracts with Customers				1,232,700,000		1,042,100,000		$ 832,000,000.0
Financing Activities (Textuals)
Repayments of Long-term Debt				0		85,000,000.0		50,000,000.0
Proceeds from Issuance of Long-term Debt				519,500,000		688,000,000.0		$ 321,000,000.0
Sub-Limit of Secured Debt				$ 50,000,000
Maximum Percentage of Consolidated Tangible Net Assets				10.00%
Tangible Capital to Tangible Assets				0.016
Maximum Percentage Debt to Capitalization				67.50%
Dividend Restrictions				$ 0
AEP Transmission Co [Member] | Utility [Member]
Money Pool Participants' Money Pool Activity and Authorized Borrowing Limits
Maximum Borrowings from Money Pool				358,400,000		374,900,000
Maximum Loans to Money Pool				259,700,000		244,400,000
Average Borrowings from Money Pool				116,300,000		152,000,000.0
Average Loans to Money Pool				55,000,000.0		52,800,000
Net Loans (Borrowings) to/from Money Pool				(155,400,000)		(119,000,000.0)
Authorized Short Term Borrowing Limit	[11]			$ 820,000,000.0		$ 795,000,000.0
Maximum and Minimum Interest Rates
Maximum Interest Rate				2.70%		3.43%		2.97%
Minimum Interest Rate				0.27%		1.77%		1.81%
Average Interest Rates for Funds Borrowed from and Loaned to Money Pool
Average Interest Rate For Funds Borrowed				1.29%		2.64%		2.27%
Average Interest Rate For Funds Loaned				1.99%		2.41%		2.10%
AEP Transmission Co [Member] | Direct Borrowing [Member]
Maximum Interest Rate for Funds Borrowed				2.70%		3.02%		2.97%
Minimum Interest Rate For Funds Borrowed				0.27%		1.91%		1.76%
Maximum Interest Rate For Funds Loaned				2.70%		3.02%		2.97%
Minimum Interest Rate for Funds Loaned				0.27%		1.91%		1.76%
Money Pool Participants' Money Pool Activity and Authorized Borrowing Limits
Maximum Borrowings from Money Pool				$ 1,400,000		$ 1,300,000
Maximum Loans to Money Pool				215,300,000		153,500,000
Average Borrowings from Money Pool				1,300,000		1,300,000
Average Loans to Money Pool				132,600,000		68,000,000.0
Borrowings from Parent				1,200,000		1,300,000
Loans to Parent				109,000,000.0		68,700,000
Authorized Short Term Borrowing Limit	[12]			$ 50,000,000.0		$ 75,000,000.0
Average Interest Rates for Funds Borrowed from and Loaned to Money Pool
Average Interest Rate For Funds Borrowed				1.20%		2.55%		2.36%
Average Interest Rate For Funds Loaned				1.13%		2.51%		2.36%
Appalachian Power Co [Member]
Long-term Debt
Senior Unsecured Notes				$ 3,937,200,000		$ 3,442,700,000
Pollution Control Bonds	[2]			546,300,000		546,100,000
Securitization Bonds				223,800,000		248,300,000
Other Long-term Debt				126,800,000		126,700,000
Total Long-term Debt Outstanding				4,834,100,000		4,363,800,000
Outstanding Long-term Debt
Principal Amount, 2021				518,300,000
Principal Amount, 2022				355,400,000
Principal Amount, 2023				26,600,000
Principal Amount, 2024				113,500,000
Principal Amount, 2025				443,900,000
Principal Amount, After 2025				3,418,300,000
Principal Amount, Total				4,876,000,000.0
Unamortized Discount, Net and Debt Issuance Costs				(41,900,000)
Total Long-term Debt Outstanding				4,834,100,000		4,363,800,000
Accounts Receivable and Accrued Unbilled Revenue
Accounts Receivable and Accrued Unbilled Revenues				136,000,000.0		120,900,000
Fees Paid to AEP Credit for Customer Accounts Receivable Sold
Revenue from Contracts with Customers				2,809,200,000		2,911,100,000		$ 2,993,200,000
Proceeds on Sale of Receivables to AEP Credit
Proceeds from Sale of Receivables to AEP Credit				1,272,900,000		1,310,300,000		1,421,000,000.0
Financing Activities (Textuals)
Repayments of Long-term Debt				140,300,000		180,500,000		124,000,000.0
Proceeds from Issuance of Long-term Debt				$ 606,900,000		478,200,000		$ 203,200,000
Maximum Percentage Debt to Capitalization				67.50%
Dividend Restrictions				$ 175,100,000
Appalachian Power Co [Member] | Utility [Member]
Money Pool Participants' Money Pool Activity and Authorized Borrowing Limits
Maximum Borrowings from Money Pool				434,300,000		270,000,000.0
Maximum Loans to Money Pool				189,000,000.0		232,200,000
Average Borrowings from Money Pool				242,800,000		115,900,000
Average Loans to Money Pool				76,300,000		51,900,000
Net Loans (Borrowings) to/from Money Pool				2,800,000		(214,600,000)
Authorized Short Term Borrowing Limit				$ 500,000,000.0		$ 500,000,000.0
Maximum and Minimum Interest Rates
Maximum Interest Rate				2.70%		3.43%		2.97%
Minimum Interest Rate				0.27%		1.77%		1.81%
Average Interest Rates for Funds Borrowed from and Loaned to Money Pool
Average Interest Rate For Funds Borrowed				2.12%		2.45%		2.26%
Average Interest Rate For Funds Loaned				0.85%		2.66%		2.21%
Indiana Michigan Power Co [Member]
Long-term Debt
Senior Unsecured Notes				$ 2,152,200,000		$ 2,150,700,000
Pollution Control Bonds	[2]			240,500,000		240,000,000.0
Notes Payable	[3]			146,700,000		168,700,000
Spent Nuclear Fuel Obligation	[4]			281,200,000		279,800,000
Other Long-term Debt				209,300,000		211,000,000.0
Total Long-term Debt Outstanding				3,029,900,000		3,050,200,000
Outstanding Long-term Debt
Principal Amount, 2021				369,600,000
Principal Amount, 2022				45,100,000
Principal Amount, 2023				273,900,000
Principal Amount, 2024				8,100,000
Principal Amount, 2025				151,500,000
Principal Amount, After 2025				2,206,200,000
Principal Amount, Total				3,054,400,000
Unamortized Discount, Net and Debt Issuance Costs				(24,500,000)
Total Long-term Debt Outstanding				3,029,900,000		3,050,200,000
Accounts Receivable and Accrued Unbilled Revenue
Accounts Receivable and Accrued Unbilled Revenues				170,500,000		141,800,000
Fees Paid to AEP Credit for Customer Accounts Receivable Sold
Revenue from Contracts with Customers				2,236,000,000.0		2,308,100,000		$ 2,381,000,000.0
Proceeds on Sale of Receivables to AEP Credit
Proceeds from Sale of Receivables to AEP Credit				1,891,800,000		1,824,200,000		1,843,000,000.0
Financing Activities (Textuals)
Repayments of Long-term Debt				93,200,000		117,100,000		884,900,000
Proceeds from Issuance of Long-term Debt				$ 69,500,000		123,300,000		$ 1,168,100,000
Maximum Percentage Debt to Capitalization				67.50%
Dividend Restrictions				$ 519,700,000
Indiana Michigan Power Co [Member] | Utility [Member]
Money Pool Participants' Money Pool Activity and Authorized Borrowing Limits
Maximum Borrowings from Money Pool				218,600,000		158,800,000
Maximum Loans to Money Pool				13,400,000		66,000,000.0
Average Borrowings from Money Pool				114,500,000		71,500,000
Average Loans to Money Pool				13,300,000		16,200,000
Net Loans (Borrowings) to/from Money Pool				(89,700,000)		(101,200,000)
Authorized Short Term Borrowing Limit				$ 500,000,000.0		$ 500,000,000.0
Maximum and Minimum Interest Rates
Maximum Interest Rate				2.70%		3.43%		2.97%
Minimum Interest Rate				0.27%		1.77%		1.81%
Average Interest Rates for Funds Borrowed from and Loaned to Money Pool
Average Interest Rate For Funds Borrowed				1.07%		2.34%		2.16%
Average Interest Rate For Funds Loaned				1.18%		2.60%		2.08%
Ohio Power Co [Member]
Long-term Debt
Senior Unsecured Notes				$ 2,429,400,000		$ 2,081,000,000.0
Other Long-term Debt				800,000		1,000,000.0
Total Long-term Debt Outstanding				2,430,200,000		2,082,000,000.0
Outstanding Long-term Debt
Principal Amount, 2021				500,100,000
Principal Amount, 2022				100,000
Principal Amount, 2023				100,000
Principal Amount, 2024				100,000
Principal Amount, 2025				100,000
Principal Amount, After 2025				1,950,300,000
Principal Amount, Total				2,450,800,000
Unamortized Discount, Net and Debt Issuance Costs				(20,600,000)
Total Long-term Debt Outstanding				2,430,200,000		2,082,000,000.0
Accounts Receivable and Accrued Unbilled Revenue
Accounts Receivable and Accrued Unbilled Revenues				398,800,000		330,300,000
Fees Paid to AEP Credit for Customer Accounts Receivable Sold
Revenue from Contracts with Customers				2,665,000,000.0		2,748,800,000		$ 3,079,900,000
Proceeds on Sale of Receivables to AEP Credit
Proceeds from Sale of Receivables to AEP Credit				2,366,200,000		2,293,600,000		2,674,500,000
Financing Activities (Textuals)
Repayments of Long-term Debt				100,000		80,300,000		397,100,000
Proceeds from Issuance of Long-term Debt				347,000,000.0		444,300,000		$ 392,800,000
Dividend Restrictions				0
Ohio Power Co [Member] | Utility [Member]
Money Pool Participants' Money Pool Activity and Authorized Borrowing Limits
Maximum Borrowings from Money Pool				353,900,000		291,200,000
Maximum Loans to Money Pool				32,800,000		178,600,000
Average Borrowings from Money Pool				182,400,000		129,200,000
Average Loans to Money Pool				25,200,000		50,100,000
Net Loans (Borrowings) to/from Money Pool				(259,200,000)		(131,000,000.0)
Authorized Short Term Borrowing Limit				$ 500,000,000.0		$ 500,000,000.0
Maximum and Minimum Interest Rates
Maximum Interest Rate				2.70%		3.43%		2.97%
Minimum Interest Rate				0.27%		1.77%		1.81%
Average Interest Rates for Funds Borrowed from and Loaned to Money Pool
Average Interest Rate For Funds Borrowed				0.99%		2.67%		2.18%
Average Interest Rate For Funds Loaned				2.06%		2.68%		2.47%
Public Service Co Of Oklahoma [Member]
Shares of Company
Beginning Balance, Shares			10,482,000	10,482,000
Ending Balance, Shares				10,482,000		10,482,000
Long-term Debt
Senior Unsecured Notes				$ 1,246,300,000		$ 1,245,600,000
Pollution Control Bonds				0		12,700,000
Other Long-term Debt				127,500,000		127,900,000
Total Long-term Debt Outstanding				1,373,800,000		1,386,200,000
Outstanding Long-term Debt
Principal Amount, 2021				500,000
Principal Amount, 2022				375,500,000
Principal Amount, 2023				500,000
Principal Amount, 2024				600,000
Principal Amount, 2025				125,600,000
Principal Amount, After 2025				875,800,000
Principal Amount, Total				1,378,500,000
Unamortized Discount, Net and Debt Issuance Costs				(4,700,000)
Total Long-term Debt Outstanding				1,373,800,000		1,386,200,000
Accounts Receivable and Accrued Unbilled Revenue
Accounts Receivable and Accrued Unbilled Revenues				85,000,000.0		101,100,000
Fees Paid to AEP Credit for Customer Accounts Receivable Sold
Revenue from Contracts with Customers				1,263,900,000		1,512,800,000		$ 1,536,400,000
Proceeds on Sale of Receivables to AEP Credit
Proceeds from Sale of Receivables to AEP Credit				1,221,000,000.0		1,442,500,000		1,484,600,000
Financing Activities (Textuals)
Repayments of Long-term Debt				13,200,000		250,500,000		500,000
Proceeds from Issuance of Long-term Debt				$ 0		349,500,000		$ 0
Maximum Percentage Debt to Capitalization				67.50%
Dividend Restrictions				$ 182,300,000
Public Service Co Of Oklahoma [Member] | Utility [Member]
Money Pool Participants' Money Pool Activity and Authorized Borrowing Limits
Maximum Borrowings from Money Pool				155,400,000		140,500,000
Maximum Loans to Money Pool				57,100,000		215,600,000
Average Borrowings from Money Pool				72,300,000		63,900,000
Average Loans to Money Pool				28,400,000		98,300,000
Net Loans (Borrowings) to/from Money Pool				(155,400,000)		38,800,000
Authorized Short Term Borrowing Limit				$ 300,000,000.0		$ 300,000,000.0
Maximum and Minimum Interest Rates
Maximum Interest Rate				2.70%		3.43%		2.97%
Minimum Interest Rate				0.27%		1.77%		1.81%
Average Interest Rates for Funds Borrowed from and Loaned to Money Pool
Average Interest Rate For Funds Borrowed				0.92%		2.85%		2.27%
Average Interest Rate For Funds Loaned				1.95%		2.27%		1.98%
Southwestern Electric Power Co [Member]
Long-term Debt
Senior Unsecured Notes				$ 2,430,800,000		$ 2,428,900,000
Notes Payable	[3]			62,400,000		65,600,000
Other Long-term Debt				143,200,000		161,100,000
Total Long-term Debt Outstanding				2,636,400,000		2,655,600,000
Outstanding Long-term Debt
Principal Amount, 2021				106,200,000
Principal Amount, 2022				281,200,000
Principal Amount, 2023				6,200,000
Principal Amount, 2024				31,200,000
Principal Amount, 2025				6,200,000
Principal Amount, After 2025				2,225,500,000
Principal Amount, Total				2,656,500,000
Unamortized Discount, Net and Debt Issuance Costs				(20,100,000)
Total Long-term Debt Outstanding				2,636,400,000		2,655,600,000
Short-term Debt
Notes Payable				35,000,000.0		18,300,000
Accounts Receivable and Accrued Unbilled Revenue
Accounts Receivable and Accrued Unbilled Revenues				158,600,000		125,200,000
Fees Paid to AEP Credit for Customer Accounts Receivable Sold
Revenue from Contracts with Customers				1,735,300,000		1,799,200,000		$ 1,817,000,000.0
Proceeds on Sale of Receivables to AEP Credit
Proceeds from Sale of Receivables to AEP Credit				1,593,800,000		1,618,500,000		1,736,100,000
Financing Activities (Textuals)
Repayments of Long-term Debt				21,200,000		59,700,000		794,500,000
Proceeds from Issuance of Long-term Debt				$ 0		0		1,065,700,000
Maximum Percentage Debt to Capitalization				67.50%
Dividend Restrictions				$ 571,900,000
Dividends Paid on Common Stock				$ (1,900,000)		(3,300,000)		$ (4,300,000)
Stock Issued During Period, Shares, Reverse Stock Splits				2,048
Stock Issued During Period, Shares, Stock Splits				1
Southwestern Electric Power Co [Member] | Utility [Member]
Money Pool Participants' Money Pool Activity and Authorized Borrowing Limits
Maximum Borrowings from Money Pool				$ 178,900,000		105,100,000
Maximum Loans to Money Pool				0		81,400,000
Average Borrowings from Money Pool				113,000,000.0		53,300,000
Average Loans to Money Pool				0		13,600,000
Net Loans (Borrowings) to/from Money Pool				(124,600,000)		(59,900,000)
Authorized Short Term Borrowing Limit				$ 350,000,000.0		$ 350,000,000.0
Maximum and Minimum Interest Rates
Maximum Interest Rate				2.70%		3.43%		2.97%
Minimum Interest Rate				0.27%		1.77%		1.81%
Average Interest Rates for Funds Borrowed from and Loaned to Money Pool
Average Interest Rate For Funds Borrowed				1.27%		2.72%		2.31%
Average Interest Rate For Funds Loaned				0.00%		2.22%		2.00%
Southwestern Electric Power Co [Member] | Nonutility [Member]
Maximum Interest Rate For Funds Loaned				2.70%		3.02%		2.97%
Minimum Interest Rate for Funds Loaned				0.27%		1.91%		1.83%
Money Pool Participants' Money Pool Activity and Authorized Borrowing Limits
Maximum Loans to Money Pool				$ 2,100,000		$ 2,100,000
Average Loans to Money Pool				2,100,000		2,000,000.0
Net Loans (Borrowings) to/from Money Pool				$ 2,100,000		$ 2,100,000
Average Interest Rates for Funds Borrowed from and Loaned to Money Pool
Average Interest Rate For Funds Loaned				1.18%		2.55%		2.36%
Southwestern Electric Power Co [Member] | Loans Payable [Member]
Short-term Debt
Debt, Weighted Average Interest Rate	[9]			2.55%		3.29%
Senior Notes [Member]
Long- term Debt by Type of Debt and Maturity
Maturity Date Low				2020
Maturity Date High				2050
Weighted Average Interest Rate				3.97%
Senior Notes [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				0.70%		2.15%
Senior Notes [Member] | Maximum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				8.13%		8.13%
Senior Notes [Member] | AEP Texas Inc. [Member]
Long- term Debt by Type of Debt and Maturity
Maturity Date Low				2022
Maturity Date High				2050
Weighted Average Interest Rate				3.70%
Senior Notes [Member] | AEP Texas Inc. [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				2.10%		2.40%
Senior Notes [Member] | AEP Texas Inc. [Member] | Maximum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				6.76%		6.76%
Senior Notes [Member] | AEP Transmission Co [Member]
Long- term Debt by Type of Debt and Maturity
Maturity Date Low				2021
Maturity Date High				2050
Weighted Average Interest Rate				3.83%
Senior Notes [Member] | AEP Transmission Co [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				3.10%		3.10%
Senior Notes [Member] | AEP Transmission Co [Member] | Maximum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				5.52%		5.52%
Senior Notes [Member] | Appalachian Power Co [Member]
Long- term Debt by Type of Debt and Maturity
Maturity Date Low				2021
Maturity Date High				2050
Weighted Average Interest Rate				4.94%
Senior Notes [Member] | Appalachian Power Co [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				3.30%		3.30%
Senior Notes [Member] | Appalachian Power Co [Member] | Maximum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				7.00%		7.00%
Senior Notes [Member] | Indiana Michigan Power Co [Member]
Long- term Debt by Type of Debt and Maturity
Maturity Date Low				2023
Maturity Date High				2048
Weighted Average Interest Rate				4.38%
Senior Notes [Member] | Indiana Michigan Power Co [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				3.20%		3.20%
Senior Notes [Member] | Indiana Michigan Power Co [Member] | Maximum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				6.05%		6.05%
Senior Notes [Member] | Ohio Power Co [Member]
Long- term Debt by Type of Debt and Maturity
Maturity Date Low				2021
Maturity Date High				2049
Weighted Average Interest Rate				4.82%
Senior Notes [Member] | Ohio Power Co [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				2.60%		4.00%
Senior Notes [Member] | Ohio Power Co [Member] | Maximum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				6.60%		6.60%
Senior Notes [Member] | Public Service Co Of Oklahoma [Member]
Long- term Debt by Type of Debt and Maturity
Maturity Date Low				2021
Maturity Date High				2049
Weighted Average Interest Rate				4.55%
Senior Notes [Member] | Public Service Co Of Oklahoma [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				3.05%		3.05%
Senior Notes [Member] | Public Service Co Of Oklahoma [Member] | Maximum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				6.63%		6.625%
Senior Notes [Member] | Southwestern Electric Power Co [Member]
Long- term Debt by Type of Debt and Maturity
Maturity Date Low				2022
Maturity Date High				2048
Weighted Average Interest Rate				4.04%
Senior Notes [Member] | Southwestern Electric Power Co [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				2.75%		2.75%
Senior Notes [Member] | Southwestern Electric Power Co [Member] | Maximum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				6.20%		6.20%
Pollution Control Bonds [Member]
Long- term Debt by Type of Debt and Maturity
Maturity Date Low	[13]			2020
Maturity Date High	[13]			2036
Weighted Average Interest Rate				2.39%
Pollution Control Bonds [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				0.18%		1.35%
Pollution Control Bonds [Member] | Maximum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				4.63%		5.38%
Pollution Control Bonds [Member] | AEP Texas Inc. [Member]
Long- term Debt by Type of Debt and Maturity
Maturity Date Low	[13]			2020
Maturity Date High	[13]			2030
Weighted Average Interest Rate				3.42%
Pollution Control Bonds [Member] | AEP Texas Inc. [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				0.90%		1.75%
Pollution Control Bonds [Member] | AEP Texas Inc. [Member] | Maximum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				4.55%		4.55%
Pollution Control Bonds [Member] | Appalachian Power Co [Member]
Long- term Debt by Type of Debt and Maturity
Maturity Date Low	[13]			2020
Maturity Date High	[13]			2036
Weighted Average Interest Rate				1.77%
Pollution Control Bonds [Member] | Appalachian Power Co [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				0.19%		1.67%
Pollution Control Bonds [Member] | Appalachian Power Co [Member] | Maximum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				4.63%		5.38%
Pollution Control Bonds [Member] | Indiana Michigan Power Co [Member]
Long- term Debt by Type of Debt and Maturity
Maturity Date Low	[13]			2021
Maturity Date High	[13]			2025
Weighted Average Interest Rate				2.21%
Pollution Control Bonds [Member] | Indiana Michigan Power Co [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				0.18%		1.79%
Pollution Control Bonds [Member] | Indiana Michigan Power Co [Member] | Maximum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				3.05%		3.05%
Pollution Control Bonds [Member] | Public Service Co Of Oklahoma [Member]
Long- term Debt by Type of Debt and Maturity
Maturity Date Low				2020
Maturity Date High				2020
Weighted Average Interest Rate
Pollution Control Bonds [Member] | Public Service Co Of Oklahoma [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate						4.45%
Pollution Control Bonds [Member] | Public Service Co Of Oklahoma [Member] | Maximum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate						4.45%
Notes Payable, Other Payables [Member]
Long- term Debt by Type of Debt and Maturity
Maturity Date Low				2020
Maturity Date High				2032
Weighted Average Interest Rate				2.34%
Notes Payable, Other Payables [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				0.84%		2.42%
Notes Payable, Other Payables [Member] | Maximum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				6.37%		6.37%
Notes Payable, Other Payables [Member] | Indiana Michigan Power Co [Member]
Long- term Debt by Type of Debt and Maturity
Maturity Date Low				2020
Maturity Date High				2025
Weighted Average Interest Rate				1.06%
Notes Payable, Other Payables [Member] | Indiana Michigan Power Co [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				0.84%		2.42%
Notes Payable, Other Payables [Member] | Indiana Michigan Power Co [Member] | Maximum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				1.29%		2.80%
Notes Payable, Other Payables [Member] | Indiana Michigan Power Co [Member] | Subsequent Event [Member]
Financing Activities (Textuals)
Repayments of Long-term Debt		$ 7,000,000	$ 8,000,000
Notes Payable, Other Payables [Member] | Southwestern Electric Power Co [Member]
Long- term Debt by Type of Debt and Maturity
Maturity Date Low				2024
Maturity Date High				2032
Weighted Average Interest Rate				5.30%
Notes Payable, Other Payables [Member] | Southwestern Electric Power Co [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				4.58%		4.58%
Notes Payable, Other Payables [Member] | Southwestern Electric Power Co [Member] | Maximum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				6.37%		6.37%
Securitization Bonds [Member]
Long- term Debt by Type of Debt and Maturity
Maturity Date Low	[14]			2020
Maturity Date High	[14]			2029
Weighted Average Interest Rate				2.78%
Securitization Bonds [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				2.01%		1.98%
Securitization Bonds [Member] | Maximum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				3.77%		5.31%
Securitization Bonds [Member] | AEP Texas Inc. [Member]
Long- term Debt by Type of Debt and Maturity
Maturity Date Low	[14]			2020
Maturity Date High	[14]			2029
Weighted Average Interest Rate				2.55%
Securitization Bonds [Member] | AEP Texas Inc. [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				2.06%		1.98%
Securitization Bonds [Member] | AEP Texas Inc. [Member] | Maximum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				2.84%		5.31%
Securitization Bonds [Member] | AEP Texas Inc. [Member] | Subsequent Event [Member]
Financing Activities (Textuals)
Repayments of Long-term Debt		11,000,000
Securitization Bonds [Member] | Appalachian Power Co [Member]
Long- term Debt by Type of Debt and Maturity
Maturity Date Low	[14]			2023
Maturity Date High	[14]			2028
Weighted Average Interest Rate				3.29%
Securitization Bonds [Member] | Appalachian Power Co [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				2.01%		2.008%
Securitization Bonds [Member] | Appalachian Power Co [Member] | Maximum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				3.77%		3.772%
Securitization Bonds [Member] | Appalachian Power Co [Member] | Subsequent Event [Member]
Financing Activities (Textuals)
Repayments of Long-term Debt		12,000,000
Junior Subordinated Notes [Member]
Long- term Debt by Type of Debt and Maturity
Maturity Date Low				2022
Maturity Date High				2023
Weighted Average Interest Rate				2.32%
Junior Subordinated Notes [Member] | 2019 Equity Units [Member]
Financing Activities (Textuals)
Proceeds from Issuance of Debt						$ 805,000,000
Junior Subordinated Notes [Member] | 2020 Equity Units [Member]
Financing Activities (Textuals)
Proceeds from Issuance of Debt				$ 850,000,000
Junior Subordinated Notes [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				1.30%		3.40%
Junior Subordinated Notes [Member] | Maximum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				3.40%		3.40%
Other Long Term Debt [Member]
Long- term Debt by Type of Debt and Maturity
Maturity Date Low				2020
Maturity Date High				2059
Weighted Average Interest Rate				1.59%
Other Long Term Debt [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				0.81%		1.15%
Other Long Term Debt [Member] | Maximum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				13.72%		13.718%
Other Long Term Debt [Member] | AEP Texas Inc. [Member]
Long- term Debt by Type of Debt and Maturity
Maturity Date Low				2022
Maturity Date High				2059
Weighted Average Interest Rate				1.41%
Other Long Term Debt [Member] | AEP Texas Inc. [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				1.40%		3.05%
Other Long Term Debt [Member] | AEP Texas Inc. [Member] | Maximum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				4.50%		4.50%
Other Long Term Debt [Member] | Appalachian Power Co [Member]
Long- term Debt by Type of Debt and Maturity
Maturity Date Low				2022
Maturity Date High				2026
Weighted Average Interest Rate				1.51%
Other Long Term Debt [Member] | Appalachian Power Co [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				1.32%		2.97%
Other Long Term Debt [Member] | Appalachian Power Co [Member] | Maximum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				13.72%		13.718%
Other Long Term Debt [Member] | Indiana Michigan Power Co [Member]
Long- term Debt by Type of Debt and Maturity
Maturity Date Low				2021
Maturity Date High				2025
Weighted Average Interest Rate				1.49%
Other Long Term Debt [Member] | Indiana Michigan Power Co [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				1.28%		2.93%
Other Long Term Debt [Member] | Indiana Michigan Power Co [Member] | Maximum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				6.00%		6.00%
Other Long Term Debt [Member] | Ohio Power Co [Member]
Long- term Debt by Type of Debt and Maturity
Maturity Date Low				2028
Maturity Date High				2028
Weighted Average Interest Rate				1.15%
Other Long Term Debt [Member] | Ohio Power Co [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				1.15%		1.15%
Other Long Term Debt [Member] | Ohio Power Co [Member] | Maximum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				1.15%		1.15%
Other Long Term Debt [Member] | Public Service Co Of Oklahoma [Member]
Long- term Debt by Type of Debt and Maturity
Maturity Date Low				2022
Maturity Date High				2027
Weighted Average Interest Rate				1.47%
Other Long Term Debt [Member] | Public Service Co Of Oklahoma [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				1.42%		3.00%
Other Long Term Debt [Member] | Public Service Co Of Oklahoma [Member] | Maximum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				3.00%		3.20%
Other Long Term Debt [Member] | Public Service Co Of Oklahoma [Member] | Subsequent Event [Member]
Financing Activities (Textuals)
Proceeds from Issuance of Long-term Debt			$ 400,000,000
Due Date			2022
Other Long Term Debt [Member] | Southwestern Electric Power Co [Member]
Long- term Debt by Type of Debt and Maturity
Maturity Date Low				2021
Maturity Date High				2035
Weighted Average Interest Rate				2.99%
Other Long Term Debt [Member] | Southwestern Electric Power Co [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				2.25%		3.08%
Other Long Term Debt [Member] | Southwestern Electric Power Co [Member] | Maximum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				4.68%		4.68%
Other Long Term Debt [Member] | Transource Energy [Member] | Subsequent Event [Member]
Financing Activities (Textuals)
Proceeds from Issuance of Long-term Debt		$ 9,000,000	$ 5,000,000
Due Date		2023	2023
Junior Subordinated Debt [Member] | 2019 Equity Units [Member]
Financing Activities (Textuals)
Debt Instrument, Interest Rate, Stated Percentage				3.40%
Junior Subordinated Debt [Member] | 2020 Equity Units [Member]
Financing Activities (Textuals)
Debt Instrument, Interest Rate, Stated Percentage				1.30%
Senior Unsecured Notes | Ohio Power Co [Member] | Subsequent Event [Member]
Financing Activities (Textuals)
Proceeds from Issuance of Long-term Debt			$ 450,000,000
Senior Unsecured Notes | Public Service Co Of Oklahoma [Member] | Subsequent Event [Member]
Financing Activities (Textuals)
Repayments of Long-term Debt		$ 250,000,000
Servicing Contracts [Member] | Appalachian Power Co [Member]
Fees Paid to AEP Credit for Customer Accounts Receivable Sold
Revenue from Contracts with Customers				$ 5,200,000		$ 7,400,000		$ 7,000,000.0
Servicing Contracts [Member] | Indiana Michigan Power Co [Member]
Fees Paid to AEP Credit for Customer Accounts Receivable Sold
Revenue from Contracts with Customers				7,900,000		11,100,000		9,200,000
Servicing Contracts [Member] | Ohio Power Co [Member]
Fees Paid to AEP Credit for Customer Accounts Receivable Sold
Revenue from Contracts with Customers				24,100,000		27,100,000		26,300,000
Servicing Contracts [Member] | Public Service Co Of Oklahoma [Member]
Fees Paid to AEP Credit for Customer Accounts Receivable Sold
Revenue from Contracts with Customers				4,800,000		7,800,000		7,900,000
Servicing Contracts [Member] | Southwestern Electric Power Co [Member]
Fees Paid to AEP Credit for Customer Accounts Receivable Sold
Revenue from Contracts with Customers				6,700,000		10,200,000		8,900,000
Retained Earnings [Member]
Financing Activities (Textuals)
Forward Equity Purchase Contract included in Current and Noncurrent liabilities				110,600,000		47,300,000		0
Dividends Paid on Common Stock				1,400,000,000		(1,300,000,000)		(1,300,000,000)
Additional Paid-in Capital [Member]
Financing Activities (Textuals)
Forward Equity Purchase Contract included in Current and Noncurrent liabilities				(85,800,000)	[15]	(9,800,000)	[16]	$ 21,800,000
Additional Paid-in Capital [Member] | 2019 Equity Units [Member]
Financing Activities (Textuals)
Forward Equity Purchase Contract included in Current and Noncurrent liabilities						$ 62,000,000
Additional Paid-in Capital [Member] | 2020 Equity Units [Member]
Financing Activities (Textuals)
Forward Equity Purchase Contract included in Current and Noncurrent liabilities				$ 121,000,000

[1] Reissued Treasury Stock used to fulfill share commitments related to AEP’s Share-based Compensation. See “Shared-based Compensation Plans” section of Note 15 for additional information.

[2] For certain series of Pollution Control Bonds, interest rates are subject to periodic adjustment.  Certain series may be purchased on demand at periodic interest adjustment dates.  Letters of credit from banks and insurance policies support certain series. Consequently, these bonds have been classified for maturity purposes as Long-term Debt Due Within One Year - Nonaffiliated on the balance sheets.

[3] Notes payable represent outstanding promissory notes issued under term loan agreements and credit agreements with a number of banks and other financial institutions. At expiration, all notes then issued and outstanding are due and payable. Interest rates are both fixed and variable. Variable rates generally relate to specified short-term interest rates.

[4] Spent Nuclear Fuel Obligation consists of a liability along with accrued interest for disposal of SNF. See “Spent Nuclear Fuel Disposal” section of Note 6 for additional information.

[5] See “Equity Units” section below for additional information.

[6] Amount includes $805 million of Junior Subordinated Notes. See “Equity Units” section below for additional information.

[7] Amount includes $850 million of Junior Subordinated Notes. See “Equity Units” section below for additional information.

[8] Amount of securitized debt for receivables as accounted for under the “Transfers and Servicing” accounting guidance.

[9] Weighted-average rate.

[10] Includes the restrictions of consolidated and non-consolidated subsidiaries.

[11] Amount represents the combined authorized short-term borrowing limit the State Transcos have from FERC or state regulatory commissions.

[12] Amount represents the combined authorized short-term borrowing limit the State Transcos have from FERC or state regulatory commissions.

[13] Certain Pollution Control Bonds are subject to redemption earlier than the maturity date.

[14] Dates represent the scheduled final payment dates for the securitization bonds. The legal maturity date is one to two years later. These bonds have been classified for maturity and repayment purposes based on the scheduled final payment date.

[15] (c)    Includes $(121) million related to a forward equity purchase contract associated with the issuance of Equity Units. See “Equity Units” section of Note 14 for additional information.

[16] (b)    Includes $(62) million related to a forward equity purchase contract associated with the issuance of Equity Units. See “Equity Units” section of Note 14 for additional information.