Financing Activities (Details) - USD ($)			1 Months Ended	3 Months Ended
		May 06, 2020	Apr. 30, 2020	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Long-term Debt
Senior Unsecured Notes				$ 22,515,800,000		$ 21,180,700,000
Pollution Control Bonds				1,999,200,000		1,998,800,000
Notes Payable				209,400,000		234,300,000
Securitization Bonds				899,100,000		1,025,100,000
Spent Nuclear Fuel Obligation	[1]			280,900,000		279,800,000
Junior Subordinated Notes	[2]			788,600,000		787,800,000
Other Long-term Debt				1,199,700,000		1,219,000,000.0
Total Long-term Debt Outstanding				27,892,700,000		26,725,500,000
Long-term Debt Due Within One Year				2,109,700,000		1,598,700,000
Long-term Debt				25,783,000,000.0		25,126,800,000
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Proceeds from Issuance of Debt	[3]			1,430,000,000.0
Repayments of Long-term Debt				$ 300,500,000	$ 220,600,000
Document Period End Date				Mar. 31, 2020
Short-term Debt:
Securitized Debt for Receivables	[4]			$ 724,000,000.0		710,000,000.0
Commercial Paper				2,709,600,000		2,110,000,000.0
Other Short-term Investments				1,000,000,000.0		0
Notes Payable				30,500,000		18,300,000
Total Short-term Debt				$ 4,464,100,000		$ 2,838,300,000
Securitized Debt for Receivables	[4],[5]			1.75%		2.42%
Comparative Accounts Receivable Information
Effective Interest Rates on Securitization of Accounts Receivable				1.75%	2.71%
Net Uncollectible Accounts Receivable Written Off				$ 4,200,000	$ 6,400,000
Customer Accounts Receivable Managed Portfolio
Accounts Receivable Retained Interest and Pledged as Collateral Less Uncollectible Accounts				850,700,000		$ 841,800,000
Total Principal Outstanding				724,000,000.0		710,000,000.0
Delinquent Securitized Accounts Receivable				43,400,000		39,600,000
Bad Debt Reserves Related to Securitization, Sale of Accounts Receivable				34,500,000		32,100,000
Unbilled Receivables Related to Securitization, Sale of Accounts Receivable				219,800,000		266,800,000
Fees Paid to AEP Credit for Customer Accounts Receivable Sold
Fees Paid to AEP Credit for Customer Accounts Receivable Sold				3,747,500,000	4,056,800,000
Financing Activities (Textuals)
Trust Fund Assets One Time Fee Obligation for Nuclear Fuel Disposition				$ 324,000,000		$ 323,000,000
Maximum Percentage Debt to Capitalization				67.50%
Total Commitment from Bank Conduits to Finance Receivables				$ 750,000,000
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%
Stockholders' Equity, Other				$ 30,200,000	55,600,000
Maximum Shares Issued Under Equity Units Conversion				9,701,860
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%
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%
Commercial Paper [Member]
Short-term Debt:
Weighted Average Interest Rate	[5]			2.24%		2.10%
Short-term Debt [Member]
Short-term Debt:
Weighted Average Interest Rate	[5]			1.53%		0.00%
Loans Payable [Member]
Short-term Debt:
Weighted Average Interest Rate	[5]			2.98%		3.29%
AEP Texas Inc. [Member]
Long-term Debt
Total Long-term Debt Outstanding				$ 4,445,400,000		$ 4,558,400,000
Long-term Debt Due Within One Year				289,000,000.0		392,100,000
Long-term Debt				4,156,400,000		4,166,300,000
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Repayments of Long-term Debt				$ 114,300,000	$ 103,500,000
Financing Activities (Textuals)
Maximum Percentage Debt to Capitalization				67.50%
AEP Texas Inc. [Member] | Utility [Member]
Maximum Interest Rate				2.24%	3.02%
Minimum Interest Rate				1.76%	2.73%
Money Pool Participants Money Pool Activity And Authorized Borrowing Limits
Maximum Borrowings from Money Pool				$ 63,900,000
Maximum Loans to Money Pool				199,700,000
Average Borrowings from Money Pool				39,000,000.0
Average Loans to Money Pool				90,300,000
Net Loans (Borrowings) to/from Money Pool				(63,900,000)
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				2.05%	2.86%
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				$ 7,100,000
Maximum and Minimum Interest Rates
Maximum Interest Rate For Funds Loaned				2.24%	3.02%
Minimum Interest Rate for Funds Loaned				1.76%	2.73%
Average Interest Rates for Funds Borrowed From and Loaned to Money Pool
Average Interest Rate For Funds Loaned				1.94%	2.87%
AEP Texas Inc. [Member] | Securitization Bonds [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%
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				$ 3,300,000
Due Date				2025
Interest Rate (Percentage)				2.06%
AEP Transmission Co [Member]
Long-term Debt
Total Long-term Debt Outstanding				$ 3,427,800,000		3,427,300,000
Long-term Debt				3,427,800,000		3,427,300,000
Financing Activities (Textuals)
Sub-Limit of Secured Debt				$ 50,000,000
Maximum Percentage of Consolidated Tangible Net Assets				10.00%
Tangible Capital to Tangible Assets				3.30%
Maximum Percentage Debt to Capitalization				67.50%
AEP Transmission Co [Member] | Utility [Member]
Maximum Interest Rate				2.24%	3.02%
Minimum Interest Rate				1.76%	2.73%
Money Pool Participants Money Pool Activity And Authorized Borrowing Limits
Maximum Borrowings from Money Pool				$ 358,400,000
Maximum Loans to Money Pool				69,800,000
Average Borrowings from Money Pool				257,600,000
Average Loans to Money Pool				32,600,000
Net Loans (Borrowings) to/from Money Pool				(261,000,000.0)
Authorized Short Term Borrowing Limit	[6]			$ 820,000,000.0
Average Interest Rates for Funds Borrowed From and Loaned to Money Pool
Average Interest Rate For Funds Borrowed				1.95%	2.83%
Average Interest Rate For Funds Loaned				1.91%	2.90%
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				1,400,000
Average Loans to Money Pool				125,100,000
Borrowings from Parent				1,300,000
Loans to Parent				93,300,000
Authorized Short Term Borrowing Limit	[7]			$ 50,000,000.0
Maximum and Minimum Interest Rates
Maximum Interest Rate for Funds Borrowed				2.24%	3.02%
Minimum Interest Rate For Funds Borrowed				1.76%	2.73%
Maximum Interest Rate For Funds Loaned				2.24%	3.02%
Minimum Interest Rate for Funds Loaned				1.76%	2.73%
Average Interest Rates for Funds Borrowed From and Loaned to Money Pool
Average Interest Rate For Funds Borrowed				1.94%	2.87%
Average Interest Rate For Funds Loaned				1.94%	2.86%
AEP Transmission Co [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			$ 525,000,000
Due Date			2050
Interest Rate (Percentage)			3.65%
Appalachian Power Co [Member]
Long-term Debt
Total Long-term Debt Outstanding				$ 4,352,400,000		4,363,800,000
Long-term Debt Due Within One Year				583,300,000		215,600,000
Long-term Debt				3,769,100,000		4,148,200,000
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Repayments of Long-term Debt				12,200,000	$ 12,000,000.0
Accounts Receivable and Accrued Unbilled Revenues
Accounts Receivable and Accrued Unbilled Revenues				121,800,000		120,900,000
Proceeds from Sale of Receivables
Proceeds from Sale of Receivables to AEP Credit				$ 352,600,000	374,400,000
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				$ 1,700,000	$ 2,200,000
Appalachian Power Co [Member] | Utility [Member]
Maximum Interest Rate				2.24%	3.02%
Minimum Interest Rate				1.76%	2.73%
Money Pool Participants Money Pool Activity And Authorized Borrowing Limits
Maximum Borrowings from Money Pool				$ 373,500,000
Maximum Loans to Money Pool				22,200,000
Average Borrowings from Money Pool				303,100,000
Average Loans to Money Pool				22,000,000.0
Net Loans (Borrowings) to/from Money Pool				(333,500,000)
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				1.95%	2.92%
Average Interest Rate For Funds Loaned				1.94%	2.79%
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%
Indiana Michigan Power Co [Member]
Long-term Debt
Total Long-term Debt Outstanding				$ 3,028,000,000.0		3,050,200,000
Long-term Debt Due Within One Year				133,600,000		139,700,000
Long-term Debt				2,894,400,000		2,910,500,000
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Repayments of Long-term Debt				23,700,000	$ 26,500,000
Accounts Receivable and Accrued Unbilled Revenues
Accounts Receivable and Accrued Unbilled Revenues				155,200,000		141,800,000
Proceeds from Sale of Receivables
Proceeds from Sale of Receivables to AEP Credit				471,400,000	478,600,000
Financing Activities (Textuals)
Trust Fund Assets One Time Fee Obligation for Nuclear Fuel Disposition				$ 324,000,000		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				$ 2,800,000	$ 2,800,000
Indiana Michigan Power Co [Member] | Utility [Member]
Maximum Interest Rate				2.24%	3.02%
Minimum Interest Rate				1.76%	2.73%
Money Pool Participants Money Pool Activity And Authorized Borrowing Limits
Maximum Borrowings from Money Pool				$ 147,500,000
Maximum Loans to Money Pool				13,300,000
Average Borrowings from Money Pool				108,400,000
Average Loans to Money Pool				13,300,000
Net Loans (Borrowings) to/from Money Pool				(90,400,000)
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				1.95%	2.80%
Average Interest Rate For Funds Loaned				1.94%	2.87%
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				$ 700,000
Due Date				2020
Interest Rate (Variable)				Variable
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				$ 1,500,000
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				$ 5,100,000
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				$ 3,800,000
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				$ 6,200,000
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				$ 6,000,000.0
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				$ 400,000
Due Date				2025
Interest Rate (Percentage)				6.00%
Ohio Power Co [Member]
Long-term Debt
Total Long-term Debt Outstanding				$ 2,429,100,000		2,082,000,000.0
Long-term Debt Due Within One Year				100,000		100,000
Long-term Debt				2,429,000,000.0		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				338,300,000		330,300,000
Proceeds from Sale of Receivables
Proceeds from Sale of Receivables to AEP Credit				570,300,000	636,800,000
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				$ 4,800,000	$ 7,800,000
Ohio Power Co [Member] | Utility [Member]
Maximum Interest Rate				2.24%	3.02%
Minimum Interest Rate				1.76%	2.73%
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				191,500,000
Average Loans to Money Pool				25,200,000
Net Loans (Borrowings) to/from Money Pool				(29,400,000)
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				1.90%	2.85%
Average Interest Rate For Funds Loaned				2.06%	0.00%
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%
Public Service Co Of Oklahoma [Member]
Long-term Debt
Total Long-term Debt Outstanding				$ 1,386,300,000		1,386,200,000
Long-term Debt Due Within One Year				263,200,000		13,200,000
Long-term Debt				1,123,100,000		1,373,000,000.0
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Repayments of Long-term Debt				100,000	$ 100,000
Accounts Receivable and Accrued Unbilled Revenues
Accounts Receivable and Accrued Unbilled Revenues				93,300,000		101,100,000
Proceeds from Sale of Receivables
Proceeds from Sale of Receivables to AEP Credit				$ 294,900,000	324,500,000
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				$ 1,300,000	$ 2,100,000
Public Service Co Of Oklahoma [Member] | Utility [Member]
Maximum Interest Rate				2.24%	3.02%
Minimum Interest Rate				1.76%	2.73%
Money Pool Participants Money Pool Activity And Authorized Borrowing Limits
Maximum Borrowings from Money Pool				$ 70,900,000
Maximum Loans to Money Pool				57,100,000
Average Borrowings from Money Pool				25,300,000
Average Loans to Money Pool				28,400,000
Net Loans (Borrowings) to/from Money Pool				(70,900,000)
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				2.00%	2.89%
Average Interest Rate For Funds Loaned				1.95%	0.00%
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				$ 100,000
Due Date				2027
Interest Rate (Percentage)				3.00%
Southwestern Electric Power Co [Member]
Long-term Debt
Total Long-term Debt Outstanding				$ 2,654,400,000		2,655,600,000
Long-term Debt Due Within One Year				121,200,000		121,200,000
Long-term Debt				2,533,200,000		2,534,400,000
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Repayments of Long-term Debt				1,600,000	$ 55,100,000
Short-term Debt:
Notes Payable				30,500,000		18,300,000
Accounts Receivable and Accrued Unbilled Revenues
Accounts Receivable and Accrued Unbilled Revenues				121,200,000		$ 125,200,000
Proceeds from Sale of Receivables
Proceeds from Sale of Receivables to AEP Credit				$ 365,600,000	371,900,000
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				$ 2,100,000	$ 2,600,000
Southwestern Electric Power Co [Member] | Utility [Member]
Maximum Interest Rate				2.24%	3.02%
Minimum Interest Rate				1.76%	2.73%
Money Pool Participants Money Pool Activity And Authorized Borrowing Limits
Maximum Borrowings from Money Pool				$ 152,800,000
Maximum Loans to Money Pool				0
Average Borrowings from Money Pool				105,500,000
Average Loans to Money Pool				0
Net Loans (Borrowings) to/from Money Pool				(148,100,000)
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				1.95%	2.81%
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
Maximum and Minimum Interest Rates
Maximum Interest Rate For Funds Loaned				2.24%	3.02%
Minimum Interest Rate for Funds Loaned				1.76%	2.73%
Average Interest Rates for Funds Borrowed From and Loaned to Money Pool
Average Interest Rate For Funds Loaned				1.94%	2.87%
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%
Southwestern Electric Power Co [Member] | Loans Payable [Member]
Short-term Debt:
Weighted Average Interest Rate	[5]			2.98%		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]			$ 5,000,000.0
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			$ 1,000,000
Due Date			2023
Transource Energy [Member] | OtherLongTermDebtTwo [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)				Varaible
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%
Maximum [Member]
Financing Activities (Textuals)
AEP Share Price for Equity Unit Conversion				$ 99.58
Shares Per Equity Unit				0.6026
Minimum [Member]
Financing Activities (Textuals)
AEP Share Price for Equity Unit Conversion				$ 82.98
Shares Per Equity Unit				0.5021
Retained Earnings [Member]
Financing Activities (Textuals)
Stockholders' Equity, Other				$ 0	$ 62,100,000
Notes Payable, Other Payables [Member] | Indiana Michigan Power Co [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

[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 $324 million and $323 million as of March 31, 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] Weighted-average rate.

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

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