Financing Activities (Details) - USD ($) $ in Millions		1 Months Ended	3 Months Ended		6 Months Ended
		Jul. 27, 2017	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Long-term Debt
Senior Unsecured Notes			$ 14,728.9		$ 14,728.9
Pollution Control Bonds			1,611.1		1,611.1		$ 1,725.1
Notes Payable			259.7		259.7		326.9
Securitization Bonds			1,555.8		1,555.8		1,705.0
Spent Nuclear Fuel Obligation	[1]		267.1		267.1		266.3
Other Long-term Debt			1,129.3		1,129.3		1,606.9
Total Long-term Debt Outstanding			19,551.9		19,551.9		20,256.4
Long-term Debt Due Within One Year			2,755.0		2,755.0		2,878.0
Long-term Debt			16,796.9		16,796.9		17,378.4
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Issuances	[2]				1,061.1
Retirements and Principal Payments					1,899.3	$ 784.1
Short-term Debt:
Securitized Debt for Receivables	[3]		519.0		519.0		673.0
Commercial Paper			1,324.0		1,324.0		1,040.0
Notes Payable			8.7		8.7		0.0
Total Short-term Debt			$ 1,851.7		$ 1,851.7		$ 1,713.0
Securitized Debt for Receivables	[3],[4]		1.09%		1.09%		0.70%
Comparative Accounts Receivable Information
Effective Interest Rates on Securitization of Accounts Receivable			1.17%	0.63%	1.09%	0.61%
Net Uncollectible Accounts Receivable Written Off			$ 5.3	$ 4.1	$ 11.2	$ 9.8
Customer Accounts Receivable Managed Portfolio
Accounts Receivable Retained Interest and Pledged as Collateral Less Uncollectible Accounts			921.7		921.7		$ 945.0
Total Principal Outstanding			519.0		519.0		673.0
Delinquent Securitized Accounts Receivable			44.3		44.3		42.7
Bad Debt Reserves Related to Securitization, Sale of Accounts Receivable			27.7		27.7		27.7
Unbilled Receivables Related to Securitization, Sale of Accounts Receivable			347.9		347.9		322.1
Financing Activities (Textuals) [Abstract]
Trust Fund Assets One Time Fee Obligation for Nuclear Fuel Disposition			310.0		310.0		311.0
Repayments of Long-term Debt					1,899.3	$ 784.1
Reacquired Pollution Controls Bonds Held by Trustees			728.0		$ 728.0
Maximum Percentage Debt to Capitalization					67.50%
Total Commitment from Bank Conduits to Finance Receivables			750.0		$ 750.0
Includes Debt Included In Liabilities Held For Sale [Member]
Long-term Debt
Senior Unsecured Notes							14,761.0
Total Long-term Debt Outstanding			$ 19,551.9		$ 19,551.9		$ 20,391.2	[5]
Commercial Paper [Member]
Short-term Debt:
Weighted Average Interest Rate	[4]		1.43%		1.43%		1.02%
Loans Payable [Member]
Short-term Debt:
Weighted Average Interest Rate	[4]		2.77%		2.77%		0.00%
AEP Subsidiaries [Member]
Long-term Debt
Long-term Debt Due Within One Year			$ 404.6		$ 404.6		$ 427.5
Long-term Debt			1,552.2		1,552.2		1,737.5
AEP Transmission Co [Member]
Long-term Debt
Total Long-term Debt Outstanding			1,931.4		1,931.4		1,932.0
Long-term Debt			1,931.4		1,931.4		1,932.0
Financing Activities (Textuals) [Abstract]
Sub-Limit of Secured Debt			$ 50.0		$ 50.0
Maximum Percentage of Consolidated Tangible Net Assets			10.00%		10.00%
Maximum Percentage Debt to Capitalization					67.50%
AEP Transmission Co [Member] | Utility [Member]
Money Pool Participants Money Pool Activity And Authorized Borrowing Limits [Abstract]
Maximum Borrowings from Money Pool					$ 333.3
Maximum Loans to Money Pool					52.9
Average Borrowings from Money Pool					170.7
Average Loans to Money Pool					12.3
Net Loans (Borrowings) to/from Money Pool			$ 246.3		246.3
Authorized Short Term Borrowing Limit	[6]				$ 795.0
Maximum and Minimum Interest Rates
Maximum Interest Rate					1.44%	0.84%
Minimum Interest Rate					0.92%	0.69%
Average Interest Rates for Funds Borrowed From and Loaned to Money Pool [Abstract]
Average Interest Rate For Funds Borrowed					1.25%	0.76%
Average Interest Rate For Funds Loaned					0.99%	0.74%
AEP Transmission Co [Member] | Direct Borrowing [Member]
Money Pool Participants Money Pool Activity And Authorized Borrowing Limits [Abstract]
Maximum Borrowings from Money Pool					$ 1.1
Maximum Loans to Money Pool					78.9
Average Borrowings from Money Pool					1.1
Average Loans to Money Pool					34.8
Borrowings from Parent			1.1		1.1
Loans to Parent			22.2		22.2
Authorized Short Term Borrowing Limit					$ 75.0
Maximum and Minimum Interest Rates
Maximum Interest Rate for Funds Borrowed					1.44%	0.84%
Minimum Interest Rate For Funds Borrowed					0.92%	0.69%
Maximum Interest Rate For Funds Loaned					1.44%	0.84%
Minimum Interest Rate for Funds Loaned					0.92%	0.69%
Average Interest Rates for Funds Borrowed From and Loaned to Money Pool [Abstract]
Average Interest Rate For Funds Borrowed					1.18%	0.75%
Average Interest Rate For Funds Loaned					1.21%	0.75%
Appalachian Power Co [Member]
Long-term Debt
Total Long-term Debt Outstanding			3,990.5		$ 3,990.5		4,033.9
Long-term Debt Due Within One Year			149.0		149.0		503.1
Long-term Debt			3,841.5		3,841.5		3,530.8
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Retirements and Principal Payments					365.9	$ 136.5
Accounts Receivable and Accrued Unbilled Revenues
Accounts Receivable and Accrued Unbilled Revenues			127.5		127.5		142.0
Fees Paid to AEP Credit for Customer Accounts Receivable Sold
Fees Paid to AEP Credit for Customer Accounts Receivable Sold			1.3	2.0	2.7	3.8
Proceeds from Sale of Receivables
Proceeds from Sale of Receivables to AEP Credit			324.2	325.5	693.9	709.9
Financing Activities (Textuals) [Abstract]
Repayments of Long-term Debt					365.9	$ 136.5
Reacquired Pollution Controls Bonds Held by Trustees			104.0		$ 104.0
Maximum Percentage Debt to Capitalization					67.50%
Appalachian Power Co [Member] | Utility [Member]
Money Pool Participants Money Pool Activity And Authorized Borrowing Limits [Abstract]
Maximum Borrowings from Money Pool					$ 231.5
Maximum Loans to Money Pool					160.7
Average Borrowings from Money Pool					179.1
Average Loans to Money Pool					36.4
Net Loans (Borrowings) to/from Money Pool			$ 100.9		100.9
Authorized Short Term Borrowing Limit					$ 600.0
Maximum and Minimum Interest Rates
Maximum Interest Rate					1.44%	0.84%
Minimum Interest Rate					0.92%	0.69%
Average Interest Rates for Funds Borrowed From and Loaned to Money Pool [Abstract]
Average Interest Rate For Funds Borrowed					1.17%	0.75%
Average Interest Rate For Funds Loaned					1.22%	0.75%
Appalachian Power Co [Member] | Pollution Control Bonds [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Retirements and Principal Payments					$ 104.4
Interest Rate (Variable)					Variable
Due Date					2017
Financing Activities (Textuals) [Abstract]
Repayments of Long-term Debt					$ 104.4
Appalachian Power Co [Member] | Securitization Bonds [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Retirements and Principal Payments					$ 11.5
Interest Rate (Percentage)			2.008%		2.008%
Due Date					2024
Financing Activities (Textuals) [Abstract]
Repayments of Long-term Debt					$ 11.5
Appalachian Power Co [Member] | Senior Unsecured Notes [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Issuances	[2]				$ 325.0
Interest Rate (Percentage)			3.30%		3.30%
Due Date					2027
Appalachian Power Co [Member] | Senior Unsecured Notes Two [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Retirements and Principal Payments					$ 250.0
Interest Rate (Percentage)			5.00%		5.00%
Due Date					2017
Financing Activities (Textuals) [Abstract]
Repayments of Long-term Debt					$ 250.0
Indiana Michigan Power Co [Member]
Long-term Debt
Total Long-term Debt Outstanding			$ 2,691.4		2,691.4		2,471.4
Long-term Debt Due Within One Year			479.8		479.8		209.3
Long-term Debt			2,211.6		2,211.6		2,262.1
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Retirements and Principal Payments					193.3	$ 53.5
Accounts Receivable and Accrued Unbilled Revenues
Accounts Receivable and Accrued Unbilled Revenues			145.6		145.6		136.7
Fees Paid to AEP Credit for Customer Accounts Receivable Sold
Fees Paid to AEP Credit for Customer Accounts Receivable Sold			1.6	1.7	3.1	3.6
Proceeds from Sale of Receivables
Proceeds from Sale of Receivables to AEP Credit			390.7	384.1	809.0	772.2
Financing Activities (Textuals) [Abstract]
Repayments of Long-term Debt					193.3	$ 53.5
Reacquired Pollution Controls Bonds Held by Trustees			50.0		$ 50.0
Maximum Percentage Debt to Capitalization					67.50%
Indiana Michigan Power Co [Member] | Utility [Member]
Money Pool Participants Money Pool Activity And Authorized Borrowing Limits [Abstract]
Maximum Borrowings from Money Pool					$ 367.4
Maximum Loans to Money Pool					12.6
Average Borrowings from Money Pool					258.6
Average Loans to Money Pool					12.6
Net Loans (Borrowings) to/from Money Pool			$ 30.8		30.8
Authorized Short Term Borrowing Limit					$ 500.0
Maximum and Minimum Interest Rates
Maximum Interest Rate					1.44%	0.84%
Minimum Interest Rate					0.92%	0.69%
Average Interest Rates for Funds Borrowed From and Loaned to Money Pool [Abstract]
Average Interest Rate For Funds Borrowed					1.20%	0.72%
Average Interest Rate For Funds Loaned					1.18%	0.75%
Indiana Michigan Power Co [Member] | Notes Payable, Other Payables [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Retirements and Principal Payments					$ 3.3
Interest Rate (Variable)					Variable
Due Date					2017
Financing Activities (Textuals) [Abstract]
Repayments of Long-term Debt					$ 3.3
Indiana Michigan Power Co [Member] | Notes Payable Two [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Retirements and Principal Payments					$ 14.9
Interest Rate (Variable)					Variable
Due Date					2019
Financing Activities (Textuals) [Abstract]
Repayments of Long-term Debt					$ 14.9
Indiana Michigan Power Co [Member] | Notes Payable, Other Payable Three [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Retirements and Principal Payments					$ 15.8
Interest Rate (Variable)					Variable
Due Date					2019
Financing Activities (Textuals) [Abstract]
Repayments of Long-term Debt					$ 15.8
Indiana Michigan Power Co [Member] | Notes Payable, Other Payable Three [Member] | Subsequent Event [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Retirements and Principal Payments		$ 5.0
Financing Activities (Textuals) [Abstract]
Repayments of Long-term Debt		5.0
Indiana Michigan Power Co [Member] | Notes Payable, Other Payable Four [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Retirements and Principal Payments					$ 15.9
Interest Rate (Variable)					Variable
Due Date					2020
Financing Activities (Textuals) [Abstract]
Repayments of Long-term Debt					$ 15.9
Indiana Michigan Power Co [Member] | Notes Payable Five [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Retirements and Principal Payments					$ 15.7
Interest Rate (Variable)					Variable
Due Date					2021
Financing Activities (Textuals) [Abstract]
Repayments of Long-term Debt					$ 15.7
Indiana Michigan Power Co [Member] | Other Long Term Debt [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Retirements and Principal Payments					$ 0.7
Interest Rate (Percentage)			6.00%		6.00%
Due Date					2025
Financing Activities (Textuals) [Abstract]
Repayments of Long-term Debt					$ 0.7
Indiana Michigan Power Co [Member] | Pollution Control Bonds [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Issuances	[2]				$ 25.0
Interest Rate (Variable)					Variable
Due Date					2019
Indiana Michigan Power Co [Member] | Pollution Control Bonds Two [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Issuances	[2]				$ 40.0
Interest Rate (Percentage)			2.05%		2.05%
Due Date					2021
Indiana Michigan Power Co [Member] | Pollution Control Bonds Three [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Issuances	[2]				$ 52.0
Interest Rate (Variable)					Variable
Due Date					2021
Indiana Michigan Power Co [Member] | Pollution Control Bonds Four [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Retirements and Principal Payments					$ 25.0
Interest Rate (Variable)					Variable
Due Date					2017
Financing Activities (Textuals) [Abstract]
Repayments of Long-term Debt					$ 25.0
Indiana Michigan Power Co [Member] | Pollution Control Bonds Five [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Retirements and Principal Payments					$ 52.0
Interest Rate (Variable)					Variable
Due Date					2017
Financing Activities (Textuals) [Abstract]
Repayments of Long-term Debt					$ 52.0
Indiana Michigan Power Co [Member] | Pollution Control Bonds Six [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Retirements and Principal Payments					$ 50.0
Interest Rate (Variable)					Variable
Due Date					2025
Financing Activities (Textuals) [Abstract]
Repayments of Long-term Debt					$ 50.0
Indiana Michigan Power Co [Member] | Senior Unsecured Notes [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Issuances	[2]				$ 300.0
Interest Rate (Percentage)			3.75%		3.75%
Due Date					2047
Ohio Power Co [Member]
Long-term Debt
Total Long-term Debt Outstanding			$ 1,742.5		$ 1,742.5		1,763.9
Long-term Debt Due Within One Year			396.8		396.8		46.4
Long-term Debt			1,345.7		1,345.7		1,717.5
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Retirements and Principal Payments					22.5	$ 372.8
Accounts Receivable and Accrued Unbilled Revenues
Accounts Receivable and Accrued Unbilled Revenues			322.4		322.4		388.3
Fees Paid to AEP Credit for Customer Accounts Receivable Sold
Fees Paid to AEP Credit for Customer Accounts Receivable Sold			4.7	7.4	10.4	15.3
Proceeds from Sale of Receivables
Proceeds from Sale of Receivables to AEP Credit			493.1	613.7	1,125.4	1,260.3
Financing Activities (Textuals) [Abstract]
Repayments of Long-term Debt					22.5	$ 372.8
Reacquired Pollution Controls Bonds Held by Trustees			345.0		345.0
Ohio Power Co [Member] | Utility [Member]
Money Pool Participants Money Pool Activity And Authorized Borrowing Limits [Abstract]
Maximum Borrowings from Money Pool					243.7
Maximum Loans to Money Pool					56.2
Average Borrowings from Money Pool					91.7
Average Loans to Money Pool					27.9
Net Loans (Borrowings) to/from Money Pool			$ 190.5		190.5
Authorized Short Term Borrowing Limit					$ 400.0
Maximum and Minimum Interest Rates
Maximum Interest Rate					1.44%	0.84%
Minimum Interest Rate					0.92%	0.69%
Average Interest Rates for Funds Borrowed From and Loaned to Money Pool [Abstract]
Average Interest Rate For Funds Borrowed					1.31%	0.79%
Average Interest Rate For Funds Loaned					0.98%	0.74%
Ohio Power Co [Member] | Securitization Bonds [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Retirements and Principal Payments					$ 22.5
Interest Rate (Percentage)			0.958%		0.958%
Due Date					2018
Financing Activities (Textuals) [Abstract]
Repayments of Long-term Debt					$ 22.5
Ohio Power Co [Member] | Securitization Bonds [Member] | Subsequent Event [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Retirements and Principal Payments		24.0
Financing Activities (Textuals) [Abstract]
Repayments of Long-term Debt		24.0
Public Service Co Of Oklahoma [Member]
Long-term Debt
Total Long-term Debt Outstanding			$ 1,286.3		1,286.3		1,286.0
Long-term Debt Due Within One Year			0.5		0.5		0.5
Long-term Debt			1,285.8		1,285.8		1,285.5
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Retirements and Principal Payments					0.2	$ 0.2
Accounts Receivable and Accrued Unbilled Revenues
Accounts Receivable and Accrued Unbilled Revenues			136.1		136.1		110.4
Fees Paid to AEP Credit for Customer Accounts Receivable Sold
Fees Paid to AEP Credit for Customer Accounts Receivable Sold			1.7	1.5	3.2	2.9
Proceeds from Sale of Receivables
Proceeds from Sale of Receivables to AEP Credit			328.7	309.2	615.5	581.3
Financing Activities (Textuals) [Abstract]
Repayments of Long-term Debt					$ 0.2	$ 0.2
Maximum Percentage Debt to Capitalization					67.50%
Public Service Co Of Oklahoma [Member] | Utility [Member]
Money Pool Participants Money Pool Activity And Authorized Borrowing Limits [Abstract]
Maximum Borrowings from Money Pool					$ 185.2
Maximum Loans to Money Pool					0.0
Average Borrowings from Money Pool					123.6
Average Loans to Money Pool					0.0
Net Loans (Borrowings) to/from Money Pool			$ 141.4		141.4
Authorized Short Term Borrowing Limit					$ 300.0
Maximum and Minimum Interest Rates
Maximum Interest Rate					1.44%	0.84%
Minimum Interest Rate					0.92%	0.69%
Average Interest Rates for Funds Borrowed From and Loaned to Money Pool [Abstract]
Average Interest Rate For Funds Borrowed					1.23%	0.76%
Average Interest Rate For Funds Loaned					0.00%	0.73%
Public Service Co Of Oklahoma [Member] | Other Long Term Debt [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Retirements and Principal Payments					$ 0.2
Interest Rate (Percentage)			3.00%		3.00%
Due Date					2027
Financing Activities (Textuals) [Abstract]
Repayments of Long-term Debt					$ 0.2
Southwestern Electric Power Co [Member]
Long-term Debt
Total Long-term Debt Outstanding			$ 2,442.7		2,442.7		2,679.1
Long-term Debt Due Within One Year			385.4		385.4		353.7
Long-term Debt			2,057.3		2,057.3		2,325.4
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Retirements and Principal Payments					351.8	$ 1.6
Short-term Debt:
Notes Payable			8.7		8.7		0.0
Accounts Receivable and Accrued Unbilled Revenues
Accounts Receivable and Accrued Unbilled Revenues			163.5		163.5		$ 130.9
Fees Paid to AEP Credit for Customer Accounts Receivable Sold
Fees Paid to AEP Credit for Customer Accounts Receivable Sold			1.8	1.7	3.4	3.2
Proceeds from Sale of Receivables
Proceeds from Sale of Receivables to AEP Credit			404.6	$ 387.4	745.8	723.5
Financing Activities (Textuals) [Abstract]
Repayments of Long-term Debt					$ 351.8	$ 1.6
Maximum Percentage Debt to Capitalization					67.50%
Southwestern Electric Power Co [Member] | Utility [Member]
Money Pool Participants Money Pool Activity And Authorized Borrowing Limits [Abstract]
Maximum Borrowings from Money Pool					$ 187.5
Maximum Loans to Money Pool					178.6
Average Borrowings from Money Pool					132.4
Average Loans to Money Pool					169.5
Net Loans (Borrowings) to/from Money Pool			58.6		58.6
Authorized Short Term Borrowing Limit					$ 350.0
Maximum and Minimum Interest Rates
Maximum Interest Rate					1.44%	0.84%
Minimum Interest Rate					0.92%	0.69%
Average Interest Rates for Funds Borrowed From and Loaned to Money Pool [Abstract]
Average Interest Rate For Funds Borrowed					1.20%	0.75%
Average Interest Rate For Funds Loaned					0.98%	0.00%
Southwestern Electric Power Co [Member] | Nonutility [Member]
Money Pool Participants Money Pool Activity And Authorized Borrowing Limits [Abstract]
Maximum Loans to Money Pool					$ 2.0
Average Loans to Money Pool					2.0
Net Loans (Borrowings) to/from Money Pool			$ 2.0		$ 2.0
Maximum and Minimum Interest Rates
Maximum Interest Rate					1.44%	0.84%
Minimum Interest Rate					0.00%	0.69%
Average Interest Rates for Funds Borrowed From and Loaned to Money Pool [Abstract]
Average Interest Rate For Funds Loaned					1.17%	0.75%
Southwestern Electric Power Co [Member] | Notes Payable, Other Payables [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Retirements and Principal Payments					$ 1.6
Interest Rate (Percentage)			4.58%		4.58%
Due Date					2032
Financing Activities (Textuals) [Abstract]
Repayments of Long-term Debt					$ 1.6
Southwestern Electric Power Co [Member] | Other Long Term Debt [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Issuances	[2]				$ 115.0
Interest Rate (Variable)					Variable
Due Date					2020
Southwestern Electric Power Co [Member] | OtherLongTermDebtTwo [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Retirements and Principal Payments					$ 100.0
Interest Rate (Variable)					Variable
Due Date					2017
Financing Activities (Textuals) [Abstract]
Repayments of Long-term Debt					$ 100.0
Southwestern Electric Power Co [Member] | Other Long Term Debt Three [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Retirements and Principal Payments					$ 0.1
Interest Rate (Percentage)			3.50%		3.50%
Due Date					2023
Financing Activities (Textuals) [Abstract]
Repayments of Long-term Debt					$ 0.1
Southwestern Electric Power Co [Member] | Other Long Term Debt Four [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Retirements and Principal Payments					$ 0.1
Interest Rate (Percentage)			4.28%		4.28%
Due Date					2023
Financing Activities (Textuals) [Abstract]
Repayments of Long-term Debt					$ 0.1
Southwestern Electric Power Co [Member] | Senior Unsecured Notes [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Retirements and Principal Payments					$ 250.0
Interest Rate (Percentage)			5.55%		5.55%
Due Date					2017
Financing Activities (Textuals) [Abstract]
Repayments of Long-term Debt					$ 250.0
Southwestern Electric Power Co [Member] | Loans Payable [Member]
Short-term Debt:
Weighted Average Interest Rate	[4]		2.77%		2.77%		0.00%
AEP Generating Co [Member] | Senior Unsecured Notes [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Retirements and Principal Payments					$ 152.7
Interest Rate (Percentage)			6.33%		6.33%
Due Date					2037
Financing Activities (Textuals) [Abstract]
Repayments of Long-term Debt					$ 152.7
AEP Texas Central Co [Member] | Securitization Bonds [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Retirements and Principal Payments					$ 27.2
Interest Rate (Percentage)			0.88%		0.88%
Due Date					2017
Financing Activities (Textuals) [Abstract]
Repayments of Long-term Debt					$ 27.2
AEP Texas Central Co [Member] | Securitization Bonds [Member] | Subsequent Event [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Retirements and Principal Payments		71.0
Financing Activities (Textuals) [Abstract]
Repayments of Long-term Debt		$ 71.0
AEP Texas Central Co [Member] | Securitization Bonds Two [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Retirements and Principal Payments					$ 89.9
Interest Rate (Percentage)			5.17%		5.17%
Due Date					2018
Financing Activities (Textuals) [Abstract]
Repayments of Long-term Debt					$ 89.9
Kentucky Power Co [Member] | Pollution Control Bonds [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Issuances	[2]				$ 65.0
Interest Rate (Percentage)			2.00%		2.00%
Due Date					2020
Kentucky Power Co [Member] | Pollution Control Bonds Two [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Retirements and Principal Payments					$ 65.0
Interest Rate (Variable)					Variable
Due Date					2017
Financing Activities (Textuals) [Abstract]
Repayments of Long-term Debt					$ 65.0
AEP Generation Resources [Member] | Other Long Term Debt [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Retirements and Principal Payments					$ 500.0
Interest Rate (Variable)					Variable
Due Date					2017
Financing Activities (Textuals) [Abstract]
Repayments of Long-term Debt					$ 500.0
Transource Missouri [Member] | Other Long Term Debt [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Issuances	[2]				$ 7.0
Interest Rate (Variable)					Variable
Due Date					2018
Transource Missouri [Member] | OtherLongTermDebtTwo [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Retirements and Principal Payments					$ 130.8
Interest Rate (Variable)					Variable
Due Date					2018
Financing Activities (Textuals) [Abstract]
Repayments of Long-term Debt					$ 130.8
Transource Energy [Member] | Other Long Term Debt [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Issuances	[2]				$ 132.1
Interest Rate (Variable)					Variable
Due Date					2020
Includes Debt Included In Liabilities Held For Sale [Member]
Long-term Debt
Total Long-term Debt Outstanding	[1]						$ 20,391.2
Long-term Debt Due Within One Year	[1]						3,013.4
Long-term Debt	[1]						$ 17,377.8

[1] Amounts include debt related to the Lawrenceburg Plant that has been classified as Liabilities Held for Sale on the balance sheet. See “Gavin, Waterford, Darby and Lawrenceburg Plants (Generation & Marketing Segment)” section of Note 6 for additional information.

[2] 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.

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

[4] Weighted average rate.

[5] Amounts include debt related to the Lawrenceburg Plant that has been classified as Liabilities Held for Sale on the balance sheet and has a fair value of $172 million. See the Assets and Liabilities Held for Sale section of Note 6 for additional information.

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