Financing Activities (Details) - USD ($)			1 Months Ended	3 Months Ended				6 Months Ended
		Aug. 06, 2020	Jul. 31, 2020	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Long-term Debt
Senior Unsecured Notes				$ 23,530,300,000				$ 23,530,300,000		$ 21,180,700,000
Pollution Control Bonds				1,936,200,000				1,936,200,000		1,998,800,000
Notes Payable				186,000,000.0				186,000,000.0		234,300,000
Securitization Bonds				866,700,000				866,700,000		1,025,100,000
Spent Nuclear Fuel Obligation	[1]			281,000,000.0				281,000,000.0		279,800,000
Junior Subordinated Notes	[2]			789,700,000				789,700,000		787,800,000
Other Long-term Debt				1,185,500,000				1,185,500,000		1,219,000,000.0
Total Long-term Debt Outstanding				28,775,400,000				28,775,400,000		26,725,500,000
Long-term Debt Due Within One Year				2,137,700,000				2,137,700,000		1,598,700,000
Long-term Debt				26,637,700,000				26,637,700,000		25,126,800,000
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Proceeds from Issuance of Debt	[3]							2,457,100,000
Repayments of Long-term Debt								$ 433,200,000	$ 728,200,000
Document Period End Date								Jun. 30, 2020
Short-term Debt:
Securitized Debt for Receivables	[4]			634,000,000.0				$ 634,000,000.0		710,000,000.0
Commercial Paper				1,403,500,000				1,403,500,000		2,110,000,000.0
364-Day Term Loan				1,000,000,000.0				1,000,000,000.0		0
COVID-19 Electricity Relief Program Loan	[5]			2,000,000.0				2,000,000.0		0
Notes Payable				37,100,000				37,100,000		18,300,000
Total Short-term Debt				$ 3,076,600,000				$ 3,076,600,000		$ 2,838,300,000
Securitized Debt for Receivables	[4],[6]			1.40%				1.40%		2.42%
Comparative Accounts Receivable Information
Effective Interest Rates on Securitization of Accounts Receivable				1.06%		2.60%		1.40%	2.66%
Net Uncollectible Accounts Receivable Written Off				$ 3,400,000		$ 4,600,000		$ 7,600,000	$ 11,000,000.0
Customer Accounts Receivable Managed Portfolio
Accounts Receivable Retained Interest and Pledged as Collateral Less Uncollectible Accounts				937,600,000				937,600,000		$ 841,800,000
Total Principal Outstanding				634,000,000.0				634,000,000.0		710,000,000.0
Delinquent Securitized Accounts Receivable				93,600,000				93,600,000		39,600,000
Bad Debt Reserves Related to Securitization, Sale of Accounts Receivable				38,700,000				38,700,000		32,100,000
Unbilled Receivables Related to Securitization, Sale of Accounts Receivable				293,200,000				293,200,000		266,800,000
Fees Paid to AEP Credit for Customer Accounts Receivable Sold
Fees Paid to AEP Credit for Customer Accounts Receivable Sold				3,494,000,000.0		3,573,600,000		7,241,500,000	7,630,400,000
Financing Activities (Textuals)
Trust Fund Assets One Time Fee Obligation for Nuclear Fuel Disposition				326,000,000				$ 326,000,000		$ 323,000,000
Maximum Percentage Debt to Capitalization								67.50%
Total Commitment from Bank Conduits to Finance Receivables				750,000,000				$ 750,000,000
Equity Units Issued								16,100,000
Per Unit Conversion for Equity Units				50				$ 50
Net Equity Units Issuance Proceeds								785,000,000
Principal Amounts of Junior Subordinated Debt				$ 1,000				$ 1,000
Forward Equity Purchase Contract Date								2022
Equity Units Annual Distribution Rate				6.125%				6.125%
Forward Equity Contract Payment Rate				2.725%				2.725%
Stockholders' Equity, Other				$ 1,600,000	$ 30,200,000	2,500,000	$ 55,600,000
Maximum Shares Issued Under Equity Units Conversion								9,701,860
Corporate unit ownership share of an equity unit				5.00%				5.00%		5.00%
Senior Unsecured Notes [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Proceeds from Issuance of Debt	[3]							$ 400,000,000.0
Due Date								2030
Interest Rate (Percentage)				2.30%				2.30%
Senior Unsecured Notes Two [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Proceeds from Issuance of Debt	[3]							$ 400,000,000.0
Due Date								2050
Interest Rate (Percentage)				3.25%				3.25%
Junior Subordinated Debt [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Proceeds from Issuance of Debt									805,000,000
Interest Rate (Percentage)				3.40%				3.40%
Commercial Paper [Member]
Short-term Debt:
Weighted Average Interest Rate	[6]			0.34%				0.34%		2.10%
Short-term Debt [Member]
Short-term Debt:
Weighted Average Interest Rate	[6]			0.78%				0.78%		0.00%
Municipal Notes [Member]
Short-term Debt:
Weighted Average Interest Rate	[5],[6]			0.00%				0.00%		0.00%
Loans Payable [Member]
Short-term Debt:
Weighted Average Interest Rate	[6]			2.35%				2.35%		3.29%
AEP Texas Inc. [Member]
Long-term Debt
Total Long-term Debt Outstanding				$ 4,362,600,000				$ 4,362,600,000		$ 4,558,400,000
Long-term Debt Due Within One Year				239,100,000				239,100,000		392,100,000
Long-term Debt				4,123,500,000				4,123,500,000		4,166,300,000
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Repayments of Long-term Debt								193,800,000	$ 181,800,000
Short-term Debt:
COVID-19 Electricity Relief Program Loan	[5]			2,000,000.0				$ 2,000,000.0		$ 0
Financing Activities (Textuals)
Maximum Percentage Debt to Capitalization								67.50%
AEP Texas Inc. [Member] | Utility [Member]
Maximum Interest Rate								2.70%	3.02%
Minimum Interest Rate								0.33%	2.68%
Money Pool Participants Money Pool Activity And Authorized Borrowing Limits
Maximum Borrowings from Money Pool								$ 320,400,000
Maximum Loans to Money Pool								199,700,000
Average Borrowings from Money Pool								154,700,000
Average Loans to Money Pool								90,300,000
Net Loans (Borrowings) to/from Money Pool				(320,400,000)				(320,400,000)
Authorized Short Term Borrowing Limit								$ 500,000,000.0
Average Interest Rates for Funds Borrowed From and Loaned to Money Pool
Average Interest Rate For Funds Borrowed								1.55%	2.81%
Average Interest Rate For Funds Loaned								1.97%	0.00%
AEP Texas Inc. [Member] | Nonutility [Member]
Money Pool Participants Money Pool Activity And Authorized Borrowing Limits
Maximum Loans to Money Pool								$ 7,500,000
Average Loans to Money Pool								7,200,000
Net Loans (Borrowings) to/from Money Pool				$ 7,200,000				$ 7,200,000
Maximum and Minimum Interest Rates
Maximum Interest Rate For Funds Loaned								2.70%	3.02%
Minimum Interest Rate for Funds Loaned								0.33%	2.68%
Average Interest Rates for Funds Borrowed From and Loaned to Money Pool
Average Interest Rate For Funds Loaned								1.87%	2.81%
AEP Texas Inc. [Member] | Pollution Control Bond [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Repayments of Long-term Debt								$ 50,600,000
Due Date								2020
Interest Rate (Percentage)				4.45%				4.45%
AEP Texas Inc. [Member] | Securitization Bonds [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Repayments of Long-term Debt								$ 28,700,000
Due Date								2020
Interest Rate (Percentage)				1.98%				1.98%
AEP Texas Inc. [Member] | Securitization Bonds [Member] | Subsequent Event [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Repayments of Long-term Debt			$ 92,000,000
AEP Texas Inc. [Member] | Securitization Bonds Two [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Repayments of Long-term Debt								$ 111,000,000.0
Due Date								2020
Interest Rate (Percentage)				5.31%				5.31%
AEP Texas Inc. [Member] | Securitization Bonds Two [Member] | Subsequent Event [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Repayments of Long-term Debt		$ 11,000,000
AEP Texas Inc. [Member] | Securitization Bonds Three [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Repayments of Long-term Debt								$ 200,000
Due Date								2024
Interest Rate (Percentage)				2.85%				2.85%
AEP Texas Inc. [Member] | Securitization Bonds Four [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Repayments of Long-term Debt								$ 3,300,000
Due Date								2025
Interest Rate (Percentage)				2.06%				2.06%
AEP Texas Inc. [Member] | Senior Unsecured Notes [Member] | Subsequent Event [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Proceeds from Issuance of Debt			$ 600,000,000
Due Date			2030
AEP Texas Inc. [Member] | Municipal Notes [Member]
Short-term Debt:
Weighted Average Interest Rate	[5],[6]			0.00%				0.00%		0.00%
AEP Transmission Co [Member]
Long-term Debt
Total Long-term Debt Outstanding				$ 3,947,400,000				$ 3,947,400,000		$ 3,427,300,000
Long-term Debt				3,947,400,000				3,947,400,000		3,427,300,000
Financing Activities (Textuals)
Sub-Limit of Secured Debt				$ 50,000,000				$ 50,000,000
Maximum Percentage of Consolidated Tangible Net Assets				10.00%				10.00%
Maximum Percentage Debt to Capitalization								67.50%
AEP Transmission Co [Member] | Utility [Member]
Maximum Interest Rate								2.70%	3.02%
Minimum Interest Rate								0.33%	2.68%
Money Pool Participants Money Pool Activity And Authorized Borrowing Limits
Maximum Borrowings from Money Pool								$ 358,400,000
Maximum Loans to Money Pool								259,700,000
Average Borrowings from Money Pool								130,900,000
Average Loans to Money Pool								85,600,000
Net Loans (Borrowings) to/from Money Pool				$ 28,000,000.0				28,000,000.0
Authorized Short Term Borrowing Limit	[7]							$ 820,000,000.0
Average Interest Rates for Funds Borrowed From and Loaned to Money Pool
Average Interest Rate For Funds Borrowed								1.94%	2.78%
Average Interest Rate For Funds Loaned								2.06%	2.83%
AEP Transmission Co [Member] | Direct Borrowing [Member]
Money Pool Participants Money Pool Activity And Authorized Borrowing Limits
Maximum Borrowings from Money Pool								$ 1,400,000
Maximum Loans to Money Pool								190,300,000
Average Borrowings from Money Pool								1,300,000
Average Loans to Money Pool								124,700,000
Borrowings from Parent				1,200,000				1,200,000
Loans to Parent				$ 90,500,000				90,500,000
Authorized Short Term Borrowing Limit	[8]							$ 50,000,000.0
Maximum and Minimum Interest Rates
Maximum Interest Rate for Funds Borrowed								2.70%	3.02%
Minimum Interest Rate For Funds Borrowed								0.50%	2.68%
Maximum Interest Rate For Funds Loaned								2.70%	3.02%
Minimum Interest Rate for Funds Loaned								0.50%	2.68%
Average Interest Rates for Funds Borrowed From and Loaned to Money Pool
Average Interest Rate For Funds Borrowed								1.88%	2.81%
Average Interest Rate For Funds Loaned								1.86%	2.80%
AEP Transmission Co [Member] | Senior Unsecured Notes [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Proceeds from Issuance of Debt	[3]							$ 525,000,000.0
Due Date								2050
Interest Rate (Percentage)				3.65%				3.65%
Appalachian Power Co [Member]
Long-term Debt
Total Long-term Debt Outstanding				$ 4,845,300,000				$ 4,845,300,000		4,363,800,000
Long-term Debt Due Within One Year				583,300,000				583,300,000		215,600,000
Long-term Debt				4,262,000,000.0				4,262,000,000.0		4,148,200,000
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Repayments of Long-term Debt								12,200,000	$ 168,000,000.0
Accounts Receivable and Accrued Unbilled Revenues
Accounts Receivable and Accrued Unbilled Revenues				116,300,000				116,300,000		120,900,000
Proceeds from Sale of Receivables
Proceeds from Sale of Receivables to AEP Credit				285,700,000		300,800,000		$ 638,300,000	675,200,000
Financing Activities (Textuals)
Maximum Percentage Debt to Capitalization								67.50%
Appalachian Power Co [Member] | Servicing Contracts [Member]
Fees Paid to AEP Credit for Customer Accounts Receivable Sold
Fees Paid to AEP Credit for Customer Accounts Receivable Sold				1,300,000		2,400,000		$ 3,000,000.0	$ 4,600,000
Appalachian Power Co [Member] | Utility [Member]
Maximum Interest Rate								2.70%	3.02%
Minimum Interest Rate								0.33%	2.68%
Money Pool Participants Money Pool Activity And Authorized Borrowing Limits
Maximum Borrowings from Money Pool								$ 434,300,000
Maximum Loans to Money Pool								174,800,000
Average Borrowings from Money Pool								331,300,000
Average Loans to Money Pool								45,300,000
Net Loans (Borrowings) to/from Money Pool				$ 82,300,000				82,300,000
Authorized Short Term Borrowing Limit								$ 500,000,000.0
Average Interest Rates for Funds Borrowed From and Loaned to Money Pool
Average Interest Rate For Funds Borrowed								2.14%	2.91%
Average Interest Rate For Funds Loaned								1.62%	2.77%
Appalachian Power Co [Member] | Securitization Bonds [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Repayments of Long-term Debt								$ 12,200,000
Due Date								2023
Interest Rate (Percentage)				2.01%				2.01%
Appalachian Power Co [Member] | Securitization Bonds [Member] | Subsequent Event [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Repayments of Long-term Debt		13,000,000
Appalachian Power Co [Member] | Senior Unsecured Notes [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Proceeds from Issuance of Debt	[3]							$ 500,000,000.0
Due Date								2050
Interest Rate (Percentage)				3.70%				3.70%
Indiana Michigan Power Co [Member]
Long-term Debt
Total Long-term Debt Outstanding				$ 3,004,800,000				$ 3,004,800,000		3,050,200,000
Long-term Debt Due Within One Year				360,800,000				360,800,000		139,700,000
Long-term Debt				2,644,000,000.0				2,644,000,000.0		2,910,500,000
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Repayments of Long-term Debt								47,600,000	$ 48,300,000
Accounts Receivable and Accrued Unbilled Revenues
Accounts Receivable and Accrued Unbilled Revenues				172,200,000				172,200,000		141,800,000
Proceeds from Sale of Receivables
Proceeds from Sale of Receivables to AEP Credit				439,900,000		415,000,000.0		911,300,000	893,600,000
Financing Activities (Textuals)
Trust Fund Assets One Time Fee Obligation for Nuclear Fuel Disposition				326,000,000				$ 326,000,000		323,000,000
Maximum Percentage Debt to Capitalization								67.50%
Indiana Michigan Power Co [Member] | Servicing Contracts [Member]
Fees Paid to AEP Credit for Customer Accounts Receivable Sold
Fees Paid to AEP Credit for Customer Accounts Receivable Sold				2,600,000		3,200,000		$ 5,400,000	$ 6,000,000.0
Indiana Michigan Power Co [Member] | Utility [Member]
Maximum Interest Rate								2.70%	3.02%
Minimum Interest Rate								0.33%	2.68%
Money Pool Participants Money Pool Activity And Authorized Borrowing Limits
Maximum Borrowings from Money Pool								$ 194,100,000
Maximum Loans to Money Pool								13,400,000
Average Borrowings from Money Pool								102,500,000
Average Loans to Money Pool								13,300,000
Net Loans (Borrowings) to/from Money Pool				$ (180,800,000)				(180,800,000)
Authorized Short Term Borrowing Limit								$ 500,000,000.0
Average Interest Rates for Funds Borrowed From and Loaned to Money Pool
Average Interest Rate For Funds Borrowed								1.80%	2.74%
Average Interest Rate For Funds Loaned								1.87%	2.82%
Indiana Michigan Power Co [Member] | Notes Payable, Other Payables [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Repayments of Long-term Debt								$ 1,300,000
Due Date								2020
Interest Rate (Variable)								Variable
Indiana Michigan Power Co [Member] | Notes Payable, Other Payables [Member] | Subsequent Event [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Repayments of Long-term Debt		$ 1,000,000	$ 8,000,000
Indiana Michigan Power Co [Member] | Notes Payable, Other Payable Two [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Repayments of Long-term Debt								$ 3,100,000
Due Date								2021
Interest Rate (Variable)								Variable
Indiana Michigan Power Co [Member] | Notes Payable, Other Payable Three [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Repayments of Long-term Debt								$ 10,200,000
Due Date								2022
Interest Rate (Variable)								Variable
Indiana Michigan Power Co [Member] | Notes Payable, Other Payable Four [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Repayments of Long-term Debt								$ 7,500,000
Due Date								2022
Interest Rate (Variable)								Variable
Indiana Michigan Power Co [Member] | Notes Payable, Other Payable Five [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Repayments of Long-term Debt								$ 12,500,000
Due Date								2023
Interest Rate (Variable)								Variable
Indiana Michigan Power Co [Member] | Notes Payable, Other Payables Six [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Repayments of Long-term Debt								$ 12,100,000
Due Date								2024
Interest Rate (Variable)								Variable
Indiana Michigan Power Co [Member] | Other Long Term Debt [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Repayments of Long-term Debt								$ 900,000
Due Date								2025
Interest Rate (Percentage)				6.00%				6.00%
Ohio Power Co [Member]
Long-term Debt
Total Long-term Debt Outstanding				$ 2,429,500,000				$ 2,429,500,000		2,082,000,000.0
Long-term Debt Due Within One Year				100,000				100,000		100,000
Long-term Debt				2,429,400,000				2,429,400,000		2,081,900,000
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Repayments of Long-term Debt								0	$ 23,400,000
Accounts Receivable and Accrued Unbilled Revenues
Accounts Receivable and Accrued Unbilled Revenues				366,700,000				366,700,000		330,300,000
Proceeds from Sale of Receivables
Proceeds from Sale of Receivables to AEP Credit				556,700,000		506,700,000		1,127,000,000.0	1,143,500,000
Ohio Power Co [Member] | Servicing Contracts [Member]
Fees Paid to AEP Credit for Customer Accounts Receivable Sold
Fees Paid to AEP Credit for Customer Accounts Receivable Sold				5,000,000.0		7,900,000		$ 9,800,000	$ 15,700,000
Ohio Power Co [Member] | Utility [Member]
Maximum Interest Rate								2.70%	3.02%
Minimum Interest Rate								0.33%	2.68%
Money Pool Participants Money Pool Activity And Authorized Borrowing Limits
Maximum Borrowings from Money Pool								$ 353,900,000
Maximum Loans to Money Pool								32,800,000
Average Borrowings from Money Pool								145,600,000
Average Loans to Money Pool								25,200,000
Net Loans (Borrowings) to/from Money Pool				$ (143,100,000)				(143,100,000)
Authorized Short Term Borrowing Limit								$ 500,000,000.0
Average Interest Rates for Funds Borrowed From and Loaned to Money Pool
Average Interest Rate For Funds Borrowed								1.80%	2.81%
Average Interest Rate For Funds Loaned								2.06%	2.73%
Ohio Power Co [Member] | Senior Unsecured Notes [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Proceeds from Issuance of Debt	[3]							$ 350,000,000.0
Due Date								2030
Interest Rate (Percentage)				2.60%				2.60%
Public Service Co Of Oklahoma [Member]
Long-term Debt
Total Long-term Debt Outstanding				$ 1,373,700,000				$ 1,373,700,000		1,386,200,000
Long-term Debt Due Within One Year				250,500,000				250,500,000		13,200,000
Long-term Debt				1,123,200,000				1,123,200,000		1,373,000,000.0
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Repayments of Long-term Debt								12,900,000	$ 250,200,000
Accounts Receivable and Accrued Unbilled Revenues
Accounts Receivable and Accrued Unbilled Revenues				115,600,000				115,600,000		101,100,000
Proceeds from Sale of Receivables
Proceeds from Sale of Receivables to AEP Credit				297,300,000		342,600,000		$ 592,200,000	667,100,000
Financing Activities (Textuals)
Maximum Percentage Debt to Capitalization								67.50%
Public Service Co Of Oklahoma [Member] | Servicing Contracts [Member]
Fees Paid to AEP Credit for Customer Accounts Receivable Sold
Fees Paid to AEP Credit for Customer Accounts Receivable Sold				1,000,000.0		2,100,000		$ 2,300,000	$ 4,200,000
Public Service Co Of Oklahoma [Member] | Utility [Member]
Maximum Interest Rate								2.70%	3.02%
Minimum Interest Rate								0.33%	2.68%
Money Pool Participants Money Pool Activity And Authorized Borrowing Limits
Maximum Borrowings from Money Pool								$ 125,400,000
Maximum Loans to Money Pool								57,100,000
Average Borrowings from Money Pool								66,800,000
Average Loans to Money Pool								28,400,000
Net Loans (Borrowings) to/from Money Pool				$ (106,900,000)				(106,900,000)
Authorized Short Term Borrowing Limit								$ 300,000,000.0
Average Interest Rates for Funds Borrowed From and Loaned to Money Pool
Average Interest Rate For Funds Borrowed								1.71%	2.85%
Average Interest Rate For Funds Loaned								1.95%	2.74%
Public Service Co Of Oklahoma [Member] | Other Long Term Debt [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Repayments of Long-term Debt								$ 200,000
Due Date								2027
Interest Rate (Percentage)				3.00%				3.00%
Public Service Co Of Oklahoma [Member] | Pollution Control Bond [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Repayments of Long-term Debt								$ 12,700,000
Due Date								2020
Interest Rate (Percentage)				4.45%				4.45%
Southwestern Electric Power Co [Member]
Long-term Debt
Total Long-term Debt Outstanding				$ 2,638,400,000				$ 2,638,400,000		2,655,600,000
Long-term Debt Due Within One Year				6,200,000				6,200,000		121,200,000
Long-term Debt				2,632,200,000				2,632,200,000		2,534,400,000
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Repayments of Long-term Debt								18,100,000	$ 56,600,000
Short-term Debt:
Notes Payable				37,100,000				37,100,000		18,300,000
Accounts Receivable and Accrued Unbilled Revenues
Accounts Receivable and Accrued Unbilled Revenues				152,800,000				152,800,000		$ 125,200,000
Proceeds from Sale of Receivables
Proceeds from Sale of Receivables to AEP Credit				381,400,000		394,500,000		$ 747,000,000.0	766,400,000
Financing Activities (Textuals)
Maximum Percentage Debt to Capitalization								67.50%
Southwestern Electric Power Co [Member] | Servicing Contracts [Member]
Fees Paid to AEP Credit for Customer Accounts Receivable Sold
Fees Paid to AEP Credit for Customer Accounts Receivable Sold				1,900,000		$ 3,400,000		$ 4,000,000.0	$ 6,000,000.0
Southwestern Electric Power Co [Member] | Utility [Member]
Maximum Interest Rate								2.70%	3.02%
Minimum Interest Rate								0.33%	2.68%
Money Pool Participants Money Pool Activity And Authorized Borrowing Limits
Maximum Borrowings from Money Pool								$ 178,900,000
Maximum Loans to Money Pool								0
Average Borrowings from Money Pool								129,300,000
Average Loans to Money Pool								0
Net Loans (Borrowings) to/from Money Pool				(130,400,000)				(130,400,000)
Authorized Short Term Borrowing Limit								$ 350,000,000.0
Average Interest Rates for Funds Borrowed From and Loaned to Money Pool
Average Interest Rate For Funds Borrowed								1.87%	2.77%
Average Interest Rate For Funds Loaned								0.00%	2.97%
Southwestern Electric Power Co [Member] | Nonutility [Member]
Money Pool Participants Money Pool Activity And Authorized Borrowing Limits
Maximum Loans to Money Pool								$ 2,100,000
Average Loans to Money Pool								2,100,000
Net Loans (Borrowings) to/from Money Pool				$ 2,100,000				$ 2,100,000
Maximum and Minimum Interest Rates
Maximum Interest Rate For Funds Loaned								2.70%	3.02%
Minimum Interest Rate for Funds Loaned								0.33%	2.68%
Average Interest Rates for Funds Borrowed From and Loaned to Money Pool
Average Interest Rate For Funds Loaned								1.87%	2.81%
Southwestern Electric Power Co [Member] | Notes Payable, Other Payables [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Repayments of Long-term Debt								$ 1,600,000
Due Date								2032
Interest Rate (Percentage)				4.58%				4.58%
Southwestern Electric Power Co [Member] | Other Long Term Debt [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Repayments of Long-term Debt								$ 15,000,000.0
Due Date								2020
Interest Rate (Variable)								Variable
Southwestern Electric Power Co [Member] | Other Long Term Debt Two [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Repayments of Long-term Debt								$ 1,500,000
Due Date								2028
Interest Rate (Percentage)				4.68%				4.68%
Southwestern Electric Power Co [Member] | Loans Payable [Member]
Short-term Debt:
Weighted Average Interest Rate	[6]			2.35%				2.35%		3.29%
Kentucky Power Co [Member] | Other Long Term Debt [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Proceeds from Issuance of Debt	[3]							$ 125,000,000.0
Due Date								2022
Interest Rate (Variable)								Variable
Transource Energy [Member] | Other Long Term Debt [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Proceeds from Issuance of Debt	[3]							$ 7,100,000
Due Date								2023
Interest Rate (Variable)								Variable
Transource Energy [Member] | Other Long Term Debt [Member] | Subsequent Event [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Proceeds from Issuance of Debt			$ 3,000,000
Due Date			2023
Transource Energy [Member] | Other Long Term Debt Two [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Repayments of Long-term Debt								$ 148,600,000
Due Date								2023
Interest Rate (Variable)								Variable
Transource Energy [Member] | Senior Unsecured Notes [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Proceeds from Issuance of Debt	[3]							$ 150,000,000.0
Due Date								2050
Interest Rate (Percentage)				2.75%				2.75%
Maximum [Member]
Financing Activities (Textuals)
AEP Share Price for Equity Unit Conversion				$ 99.58				$ 99.58
Shares Per Equity Unit				0.6026				0.6026
Minimum [Member]
Financing Activities (Textuals)
AEP Share Price for Equity Unit Conversion				$ 82.98				$ 82.98
Shares Per Equity Unit				0.5021				0.5021
Retained Earnings [Member]
Financing Activities (Textuals)
Stockholders' Equity, Other									$ 62,000,000

[1] Pursuant to the Nuclear Waste Policy Act of 1982, I&M, a nuclear licensee, has an obligation to the United States Department of Energy for SNF disposal.  The obligation includes a one-time fee for nuclear fuel consumed prior to April 7, 1983.  Trust fund assets related to this obligation were $326 million and $323 million as of June 30, 2020 and December 31, 2019, respectively, and are included in Spent Nuclear Fuel and Decommissioning Trusts on the balance sheets.

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

[3] Amounts indicated on the statements of cash flows are net of issuance costs and premium or discount and will not tie to the issuance amounts.

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

[5] Principal amount of loan shall not bear interest if paid in full by the maturity date. Unpaid principal after the maturity date will accrue interest of 2% per annum beginning the first day after the maturity date until all outstanding principal is paid.

[6] Weighted-average rate.

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

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