XML 93 R45.htm IDEA: XBRL DOCUMENT v2.4.0.8
Derivatives and Hedging (Details) (USD $)
 3 Months Ended 6 Months Ended 12 Months Ended 3 Months Ended 6 Months Ended 3 Months Ended 6 Months Ended 3 Months Ended 6 Months Ended 3 Months Ended 6 Months Ended 3 Months Ended 6 Months Ended 6 Months Ended 12 Months Ended 6 Months Ended 12 Months Ended 6 Months Ended 12 Months Ended 6 Months Ended 12 Months Ended 6 Months Ended 12 Months Ended 6 Months Ended 12 Months Ended 6 Months Ended 12 Months Ended 6 Months Ended 12 Months Ended 6 Months Ended 12 Months Ended 6 Months Ended 12 Months Ended 6 Months Ended 12 Months Ended 6 Months Ended 12 Months Ended 3 Months Ended 6 Months Ended 3 Months Ended 6 Months Ended 3 Months Ended 6 Months Ended 3 Months Ended 6 Months Ended 3 Months Ended 6 Months Ended 3 Months Ended 6 Months Ended 3 Months Ended 6 Months Ended 3 Months Ended 6 Months Ended 3 Months Ended 6 Months Ended 3 Months Ended 6 Months Ended 3 Months Ended 6 Months Ended 3 Months Ended 6 Months Ended 3 Months Ended 6 Months Ended 3 Months Ended 6 Months Ended 3 Months Ended 6 Months Ended 3 Months Ended 6 Months Ended 3 Months Ended 6 Months Ended 3 Months Ended 6 Months Ended 3 Months Ended 6 Months Ended 3 Months Ended 6 Months Ended 3 Months Ended 6 Months Ended 3 Months Ended 6 Months Ended 3 Months Ended 6 Months Ended 3 Months Ended 6 Months Ended 3 Months Ended 6 Months Ended 3 Months Ended 6 Months Ended 3 Months Ended 6 Months Ended 3 Months Ended 6 Months Ended 3 Months Ended 6 Months Ended
Jun. 30, 2013
T
MMBTU
gal
MWh
Jun. 30, 2012
Jun. 30, 2013
T
MMBTU
gal
MWh
Jun. 30, 2012
Dec. 31, 2012
gal
MMBTU
MWh
T
Jun. 30, 2013
Appalachian Power Co [Member]
gal
MWh
T
MMBTU
Jun. 30, 2012
Appalachian Power Co [Member]
Jun. 30, 2013
Appalachian Power Co [Member]
gal
MWh
T
MMBTU
Jun. 30, 2012
Appalachian Power Co [Member]
Dec. 31, 2012
Appalachian Power Co [Member]
gal
MWh
T
MMBTU
Jun. 30, 2013
Indiana Michigan Power Co [Member]
MWh
MMBTU
T
gal
Jun. 30, 2012
Indiana Michigan Power Co [Member]
Jun. 30, 2013
Indiana Michigan Power Co [Member]
MWh
MMBTU
T
gal
Jun. 30, 2012
Indiana Michigan Power Co [Member]
Dec. 31, 2012
Indiana Michigan Power Co [Member]
T
MMBTU
MWh
gal
Jun. 30, 2013
Ohio Power Co [Member]
T
MWh
gal
MMBTU
Jun. 30, 2012
Ohio Power Co [Member]
Jun. 30, 2013
Ohio Power Co [Member]
T
MWh
gal
MMBTU
Jun. 30, 2012
Ohio Power Co [Member]
Dec. 31, 2012
Ohio Power Co [Member]
MWh
T
MMBTU
gal
Jun. 30, 2013
Public Service Co Of Oklahoma [Member]
MMBTU
MWh
gal
T
Jun. 30, 2012
Public Service Co Of Oklahoma [Member]
Jun. 30, 2013
Public Service Co Of Oklahoma [Member]
MMBTU
MWh
gal
T
Jun. 30, 2012
Public Service Co Of Oklahoma [Member]
Dec. 31, 2012
Public Service Co Of Oklahoma [Member]
T
MMBTU
MWh
gal
Jun. 30, 2013
Southwestern Electric Power Co [Member]
T
MWh
gal
MMBTU
Jun. 30, 2012
Southwestern Electric Power Co [Member]
Jun. 30, 2013
Southwestern Electric Power Co [Member]
T
MWh
gal
MMBTU
Jun. 30, 2012
Southwestern Electric Power Co [Member]
Dec. 31, 2012
Southwestern Electric Power Co [Member]
gal
MMBTU
T
MWh
Jun. 30, 2013
Risk Management Contracts [Member]
Dec. 31, 2012
Risk Management Contracts [Member]
Jun. 30, 2013
Risk Management Contracts [Member]
Appalachian Power Co [Member]
Dec. 31, 2012
Risk Management Contracts [Member]
Appalachian Power Co [Member]
Jun. 30, 2013
Risk Management Contracts [Member]
Indiana Michigan Power Co [Member]
Dec. 31, 2012
Risk Management Contracts [Member]
Indiana Michigan Power Co [Member]
Jun. 30, 2013
Risk Management Contracts [Member]
Ohio Power Co [Member]
Dec. 31, 2012
Risk Management Contracts [Member]
Ohio Power Co [Member]
Jun. 30, 2013
Risk Management Contracts [Member]
Public Service Co Of Oklahoma [Member]
Dec. 31, 2012
Risk Management Contracts [Member]
Public Service Co Of Oklahoma [Member]
Jun. 30, 2013
Risk Management Contracts [Member]
Southwestern Electric Power Co [Member]
Dec. 31, 2012
Risk Management Contracts [Member]
Southwestern Electric Power Co [Member]
Jun. 30, 2012
Cash Flow Hedges [Member]
Mar. 31, 2012
Cash Flow Hedges [Member]
Dec. 31, 2011
Cash Flow Hedges [Member]
Jun. 30, 2012
Cash Flow Hedges [Member]
Appalachian Power Co [Member]
Mar. 31, 2012
Cash Flow Hedges [Member]
Appalachian Power Co [Member]
Dec. 31, 2011
Cash Flow Hedges [Member]
Appalachian Power Co [Member]
Jun. 30, 2012
Cash Flow Hedges [Member]
Indiana Michigan Power Co [Member]
Mar. 31, 2012
Cash Flow Hedges [Member]
Indiana Michigan Power Co [Member]
Dec. 31, 2011
Cash Flow Hedges [Member]
Indiana Michigan Power Co [Member]
Jun. 30, 2012
Cash Flow Hedges [Member]
Ohio Power Co [Member]
Mar. 31, 2012
Cash Flow Hedges [Member]
Ohio Power Co [Member]
Dec. 31, 2011
Cash Flow Hedges [Member]
Ohio Power Co [Member]
Jun. 30, 2012
Cash Flow Hedges [Member]
Public Service Co Of Oklahoma [Member]
Mar. 31, 2012
Cash Flow Hedges [Member]
Public Service Co Of Oklahoma [Member]
Dec. 31, 2011
Cash Flow Hedges [Member]
Public Service Co Of Oklahoma [Member]
Jun. 30, 2012
Cash Flow Hedges [Member]
Southwestern Electric Power Co [Member]
Mar. 31, 2012
Cash Flow Hedges [Member]
Southwestern Electric Power Co [Member]
Dec. 31, 2011
Cash Flow Hedges [Member]
Southwestern Electric Power Co [Member]
Jun. 30, 2013
Commodity [Member]
Dec. 31, 2012
Commodity [Member]
Jun. 30, 2013
Commodity [Member]
Appalachian Power Co [Member]
Dec. 31, 2012
Commodity [Member]
Appalachian Power Co [Member]
Jun. 30, 2013
Commodity [Member]
Indiana Michigan Power Co [Member]
Dec. 31, 2012
Commodity [Member]
Indiana Michigan Power Co [Member]
Jun. 30, 2013
Commodity [Member]
Ohio Power Co [Member]
Dec. 31, 2012
Commodity [Member]
Ohio Power Co [Member]
Jun. 30, 2013
Commodity [Member]
Public Service Co Of Oklahoma [Member]
Dec. 31, 2012
Commodity [Member]
Public Service Co Of Oklahoma [Member]
Jun. 30, 2013
Commodity [Member]
Southwestern Electric Power Co [Member]
Dec. 31, 2012
Commodity [Member]
Southwestern Electric Power Co [Member]
Jun. 30, 2013
Commodity [Member]
Risk Management Contracts [Member]
Dec. 31, 2012
Commodity [Member]
Risk Management Contracts [Member]
Jun. 30, 2013
Commodity [Member]
Risk Management Contracts [Member]
Appalachian Power Co [Member]
Dec. 31, 2012
Commodity [Member]
Risk Management Contracts [Member]
Appalachian Power Co [Member]
Jun. 30, 2013
Commodity [Member]
Risk Management Contracts [Member]
Indiana Michigan Power Co [Member]
Dec. 31, 2012
Commodity [Member]
Risk Management Contracts [Member]
Indiana Michigan Power Co [Member]
Jun. 30, 2013
Commodity [Member]
Risk Management Contracts [Member]
Ohio Power Co [Member]
Dec. 31, 2012
Commodity [Member]
Risk Management Contracts [Member]
Ohio Power Co [Member]
Jun. 30, 2013
Commodity [Member]
Risk Management Contracts [Member]
Public Service Co Of Oklahoma [Member]
Dec. 31, 2012
Commodity [Member]
Risk Management Contracts [Member]
Public Service Co Of Oklahoma [Member]
Jun. 30, 2013
Commodity [Member]
Risk Management Contracts [Member]
Southwestern Electric Power Co [Member]
Dec. 31, 2012
Commodity [Member]
Risk Management Contracts [Member]
Southwestern Electric Power Co [Member]
Jun. 30, 2013
Commodity [Member]
Hedging Contracts [Member]
Dec. 31, 2012
Commodity [Member]
Hedging Contracts [Member]
Jun. 30, 2013
Commodity [Member]
Hedging Contracts [Member]
Appalachian Power Co [Member]
Dec. 31, 2012
Commodity [Member]
Hedging Contracts [Member]
Appalachian Power Co [Member]
Jun. 30, 2013
Commodity [Member]
Hedging Contracts [Member]
Indiana Michigan Power Co [Member]
Dec. 31, 2012
Commodity [Member]
Hedging Contracts [Member]
Indiana Michigan Power Co [Member]
Jun. 30, 2013
Commodity [Member]
Hedging Contracts [Member]
Ohio Power Co [Member]
Dec. 31, 2012
Commodity [Member]
Hedging Contracts [Member]
Ohio Power Co [Member]
Jun. 30, 2013
Commodity [Member]
Hedging Contracts [Member]
Public Service Co Of Oklahoma [Member]
Dec. 31, 2012
Commodity [Member]
Hedging Contracts [Member]
Public Service Co Of Oklahoma [Member]
Jun. 30, 2013
Commodity [Member]
Hedging Contracts [Member]
Southwestern Electric Power Co [Member]
Dec. 31, 2012
Commodity [Member]
Hedging Contracts [Member]
Southwestern Electric Power Co [Member]
Jun. 30, 2013
Interest Rate and Foreign Currency [Member]
Dec. 31, 2012
Interest Rate and Foreign Currency [Member]
Jun. 30, 2013
Interest Rate and Foreign Currency [Member]
Appalachian Power Co [Member]
Dec. 31, 2012
Interest Rate and Foreign Currency [Member]
Appalachian Power Co [Member]
Jun. 30, 2013
Interest Rate and Foreign Currency [Member]
Indiana Michigan Power Co [Member]
Dec. 31, 2012
Interest Rate and Foreign Currency [Member]
Indiana Michigan Power Co [Member]
Jun. 30, 2013
Interest Rate and Foreign Currency [Member]
Ohio Power Co [Member]
Dec. 31, 2012
Interest Rate and Foreign Currency [Member]
Ohio Power Co [Member]
Jun. 30, 2013
Interest Rate and Foreign Currency [Member]
Public Service Co Of Oklahoma [Member]
Dec. 31, 2012
Interest Rate and Foreign Currency [Member]
Public Service Co Of Oklahoma [Member]
Jun. 30, 2013
Interest Rate and Foreign Currency [Member]
Southwestern Electric Power Co [Member]
Dec. 31, 2012
Interest Rate and Foreign Currency [Member]
Southwestern Electric Power Co [Member]
Jun. 30, 2013
Interest Rate and Foreign Currency [Member]
Hedging Contracts [Member]
Dec. 31, 2012
Interest Rate and Foreign Currency [Member]
Hedging Contracts [Member]
Jun. 30, 2013
Interest Rate and Foreign Currency [Member]
Hedging Contracts [Member]
Appalachian Power Co [Member]
Dec. 31, 2012
Interest Rate and Foreign Currency [Member]
Hedging Contracts [Member]
Appalachian Power Co [Member]
Jun. 30, 2013
Interest Rate and Foreign Currency [Member]
Hedging Contracts [Member]
Indiana Michigan Power Co [Member]
Dec. 31, 2012
Interest Rate and Foreign Currency [Member]
Hedging Contracts [Member]
Indiana Michigan Power Co [Member]
Jun. 30, 2013
Interest Rate and Foreign Currency [Member]
Hedging Contracts [Member]
Ohio Power Co [Member]
Dec. 31, 2012
Interest Rate and Foreign Currency [Member]
Hedging Contracts [Member]
Ohio Power Co [Member]
Jun. 30, 2013
Interest Rate and Foreign Currency [Member]
Hedging Contracts [Member]
Public Service Co Of Oklahoma [Member]
Dec. 31, 2012
Interest Rate and Foreign Currency [Member]
Hedging Contracts [Member]
Public Service Co Of Oklahoma [Member]
Jun. 30, 2013
Interest Rate and Foreign Currency [Member]
Hedging Contracts [Member]
Southwestern Electric Power Co [Member]
Dec. 31, 2012
Interest Rate and Foreign Currency [Member]
Hedging Contracts [Member]
Southwestern Electric Power Co [Member]
Jun. 30, 2013
Gross Amounts of Risk Management Assets/Liabilities Recognized [Member]
Dec. 31, 2012
Gross Amounts of Risk Management Assets/Liabilities Recognized [Member]
Jun. 30, 2013
Gross Amounts of Risk Management Assets/Liabilities Recognized [Member]
Appalachian Power Co [Member]
Dec. 31, 2012
Gross Amounts of Risk Management Assets/Liabilities Recognized [Member]
Appalachian Power Co [Member]
Jun. 30, 2013
Gross Amounts of Risk Management Assets/Liabilities Recognized [Member]
Indiana Michigan Power Co [Member]
Dec. 31, 2012
Gross Amounts of Risk Management Assets/Liabilities Recognized [Member]
Indiana Michigan Power Co [Member]
Jun. 30, 2013
Gross Amounts of Risk Management Assets/Liabilities Recognized [Member]
Ohio Power Co [Member]
Dec. 31, 2012
Gross Amounts of Risk Management Assets/Liabilities Recognized [Member]
Ohio Power Co [Member]
Jun. 30, 2013
Gross Amounts of Risk Management Assets/Liabilities Recognized [Member]
Public Service Co Of Oklahoma [Member]
Dec. 31, 2012
Gross Amounts of Risk Management Assets/Liabilities Recognized [Member]
Public Service Co Of Oklahoma [Member]
Jun. 30, 2013
Gross Amounts of Risk Management Assets/Liabilities Recognized [Member]
Southwestern Electric Power Co [Member]
Dec. 31, 2012
Gross Amounts of Risk Management Assets/Liabilities Recognized [Member]
Southwestern Electric Power Co [Member]
Jun. 30, 2013
Gross Amounts Offset in the Statement of Financial Position [Member]
Dec. 31, 2012
Gross Amounts Offset in the Statement of Financial Position [Member]
Jun. 30, 2013
Gross Amounts Offset in the Statement of Financial Position [Member]
Appalachian Power Co [Member]
Dec. 31, 2012
Gross Amounts Offset in the Statement of Financial Position [Member]
Appalachian Power Co [Member]
Jun. 30, 2013
Gross Amounts Offset in the Statement of Financial Position [Member]
Indiana Michigan Power Co [Member]
Dec. 31, 2012
Gross Amounts Offset in the Statement of Financial Position [Member]
Indiana Michigan Power Co [Member]
Jun. 30, 2013
Gross Amounts Offset in the Statement of Financial Position [Member]
Ohio Power Co [Member]
Dec. 31, 2012
Gross Amounts Offset in the Statement of Financial Position [Member]
Ohio Power Co [Member]
Jun. 30, 2013
Gross Amounts Offset in the Statement of Financial Position [Member]
Public Service Co Of Oklahoma [Member]
Dec. 31, 2012
Gross Amounts Offset in the Statement of Financial Position [Member]
Public Service Co Of Oklahoma [Member]
Jun. 30, 2013
Gross Amounts Offset in the Statement of Financial Position [Member]
Southwestern Electric Power Co [Member]
Dec. 31, 2012
Gross Amounts Offset in the Statement of Financial Position [Member]
Southwestern Electric Power Co [Member]
Jun. 30, 2013
Net Amounts of Assets/Liabilities Presented in the Statement of Financial Position [Member]
Dec. 31, 2012
Net Amounts of Assets/Liabilities Presented in the Statement of Financial Position [Member]
Jun. 30, 2013
Net Amounts of Assets/Liabilities Presented in the Statement of Financial Position [Member]
Appalachian Power Co [Member]
Dec. 31, 2012
Net Amounts of Assets/Liabilities Presented in the Statement of Financial Position [Member]
Appalachian Power Co [Member]
Jun. 30, 2013
Net Amounts of Assets/Liabilities Presented in the Statement of Financial Position [Member]
Indiana Michigan Power Co [Member]
Dec. 31, 2012
Net Amounts of Assets/Liabilities Presented in the Statement of Financial Position [Member]
Indiana Michigan Power Co [Member]
Jun. 30, 2013
Net Amounts of Assets/Liabilities Presented in the Statement of Financial Position [Member]
Ohio Power Co [Member]
Dec. 31, 2012
Net Amounts of Assets/Liabilities Presented in the Statement of Financial Position [Member]
Ohio Power Co [Member]
Jun. 30, 2013
Net Amounts of Assets/Liabilities Presented in the Statement of Financial Position [Member]
Public Service Co Of Oklahoma [Member]
Dec. 31, 2012
Net Amounts of Assets/Liabilities Presented in the Statement of Financial Position [Member]
Public Service Co Of Oklahoma [Member]
Jun. 30, 2013
Net Amounts of Assets/Liabilities Presented in the Statement of Financial Position [Member]
Southwestern Electric Power Co [Member]
Dec. 31, 2012
Net Amounts of Assets/Liabilities Presented in the Statement of Financial Position [Member]
Southwestern Electric Power Co [Member]
Jun. 30, 2013
Utility Operations Revenues [Member]
Jun. 30, 2012
Utility Operations Revenues [Member]
Jun. 30, 2013
Utility Operations Revenues [Member]
Jun. 30, 2012
Utility Operations Revenues [Member]
Jun. 30, 2013
Electric Generation, Transmission and Distribution Revenues [Member]
Appalachian Power Co [Member]
Jun. 30, 2012
Electric Generation, Transmission and Distribution Revenues [Member]
Appalachian Power Co [Member]
Jun. 30, 2013
Electric Generation, Transmission and Distribution Revenues [Member]
Appalachian Power Co [Member]
Jun. 30, 2012
Electric Generation, Transmission and Distribution Revenues [Member]
Appalachian Power Co [Member]
Jun. 30, 2013
Electric Generation, Transmission and Distribution Revenues [Member]
Indiana Michigan Power Co [Member]
Jun. 30, 2012
Electric Generation, Transmission and Distribution Revenues [Member]
Indiana Michigan Power Co [Member]
Jun. 30, 2013
Electric Generation, Transmission and Distribution Revenues [Member]
Indiana Michigan Power Co [Member]
Jun. 30, 2012
Electric Generation, Transmission and Distribution Revenues [Member]
Indiana Michigan Power Co [Member]
Jun. 30, 2013
Electric Generation, Transmission and Distribution Revenues [Member]
Ohio Power Co [Member]
Jun. 30, 2012
Electric Generation, Transmission and Distribution Revenues [Member]
Ohio Power Co [Member]
Jun. 30, 2013
Electric Generation, Transmission and Distribution Revenues [Member]
Ohio Power Co [Member]
Jun. 30, 2012
Electric Generation, Transmission and Distribution Revenues [Member]
Ohio Power Co [Member]
Jun. 30, 2013
Electric Generation, Transmission and Distribution Revenues [Member]
Public Service Co Of Oklahoma [Member]
Jun. 30, 2012
Electric Generation, Transmission and Distribution Revenues [Member]
Public Service Co Of Oklahoma [Member]
Jun. 30, 2013
Electric Generation, Transmission and Distribution Revenues [Member]
Public Service Co Of Oklahoma [Member]
Jun. 30, 2012
Electric Generation, Transmission and Distribution Revenues [Member]
Public Service Co Of Oklahoma [Member]
Jun. 30, 2013
Electric Generation, Transmission and Distribution Revenues [Member]
Southwestern Electric Power Co [Member]
Jun. 30, 2012
Electric Generation, Transmission and Distribution Revenues [Member]
Southwestern Electric Power Co [Member]
Jun. 30, 2013
Electric Generation, Transmission and Distribution Revenues [Member]
Southwestern Electric Power Co [Member]
Jun. 30, 2012
Electric Generation, Transmission and Distribution Revenues [Member]
Southwestern Electric Power Co [Member]
Jun. 30, 2013
Sales to AEP Affiliates [Member]
Appalachian Power Co [Member]
Jun. 30, 2012
Sales to AEP Affiliates [Member]
Appalachian Power Co [Member]
Jun. 30, 2013
Sales to AEP Affiliates [Member]
Appalachian Power Co [Member]
Jun. 30, 2012
Sales to AEP Affiliates [Member]
Appalachian Power Co [Member]
Jun. 30, 2013
Sales to AEP Affiliates [Member]
Indiana Michigan Power Co [Member]
Jun. 30, 2012
Sales to AEP Affiliates [Member]
Indiana Michigan Power Co [Member]
Jun. 30, 2013
Sales to AEP Affiliates [Member]
Indiana Michigan Power Co [Member]
Jun. 30, 2012
Sales to AEP Affiliates [Member]
Indiana Michigan Power Co [Member]
Jun. 30, 2013
Sales to AEP Affiliates [Member]
Ohio Power Co [Member]
Jun. 30, 2012
Sales to AEP Affiliates [Member]
Ohio Power Co [Member]
Jun. 30, 2013
Sales to AEP Affiliates [Member]
Ohio Power Co [Member]
Jun. 30, 2012
Sales to AEP Affiliates [Member]
Ohio Power Co [Member]
Jun. 30, 2013
Sales to AEP Affiliates [Member]
Public Service Co Of Oklahoma [Member]
Jun. 30, 2012
Sales to AEP Affiliates [Member]
Public Service Co Of Oklahoma [Member]
Jun. 30, 2013
Sales to AEP Affiliates [Member]
Public Service Co Of Oklahoma [Member]
Jun. 30, 2012
Sales to AEP Affiliates [Member]
Public Service Co Of Oklahoma [Member]
Jun. 30, 2013
Sales to AEP Affiliates [Member]
Southwestern Electric Power Co [Member]
Jun. 30, 2012
Sales to AEP Affiliates [Member]
Southwestern Electric Power Co [Member]
Jun. 30, 2013
Sales to AEP Affiliates [Member]
Southwestern Electric Power Co [Member]
Jun. 30, 2012
Sales to AEP Affiliates [Member]
Southwestern Electric Power Co [Member]
Jun. 30, 2013
Other Revenues [Member]
Jun. 30, 2012
Other Revenues [Member]
Jun. 30, 2013
Other Revenues [Member]
Jun. 30, 2012
Other Revenues [Member]
Jun. 30, 2013
Fuel and Other Consumables Used for Electric Generation [Member]
Appalachian Power Co [Member]
Jun. 30, 2012
Fuel and Other Consumables Used for Electric Generation [Member]
Appalachian Power Co [Member]
Jun. 30, 2013
Fuel and Other Consumables Used for Electric Generation [Member]
Appalachian Power Co [Member]
Jun. 30, 2012
Fuel and Other Consumables Used for Electric Generation [Member]
Appalachian Power Co [Member]
Jun. 30, 2013
Fuel and Other Consumables Used for Electric Generation [Member]
Indiana Michigan Power Co [Member]
Jun. 30, 2012
Fuel and Other Consumables Used for Electric Generation [Member]
Indiana Michigan Power Co [Member]
Jun. 30, 2013
Fuel and Other Consumables Used for Electric Generation [Member]
Indiana Michigan Power Co [Member]
Jun. 30, 2012
Fuel and Other Consumables Used for Electric Generation [Member]
Indiana Michigan Power Co [Member]
Jun. 30, 2013
Fuel and Other Consumables Used for Electric Generation [Member]
Ohio Power Co [Member]
Jun. 30, 2012
Fuel and Other Consumables Used for Electric Generation [Member]
Ohio Power Co [Member]
Jun. 30, 2013
Fuel and Other Consumables Used for Electric Generation [Member]
Ohio Power Co [Member]
Jun. 30, 2012
Fuel and Other Consumables Used for Electric Generation [Member]
Ohio Power Co [Member]
Jun. 30, 2013
Fuel and Other Consumables Used for Electric Generation [Member]
Public Service Co Of Oklahoma [Member]
Jun. 30, 2012
Fuel and Other Consumables Used for Electric Generation [Member]
Public Service Co Of Oklahoma [Member]
Jun. 30, 2013
Fuel and Other Consumables Used for Electric Generation [Member]
Public Service Co Of Oklahoma [Member]
Jun. 30, 2012
Fuel and Other Consumables Used for Electric Generation [Member]
Public Service Co Of Oklahoma [Member]
Jun. 30, 2013
Fuel and Other Consumables Used for Electric Generation [Member]
Southwestern Electric Power Co [Member]
Jun. 30, 2012
Fuel and Other Consumables Used for Electric Generation [Member]
Southwestern Electric Power Co [Member]
Jun. 30, 2013
Fuel and Other Consumables Used for Electric Generation [Member]
Southwestern Electric Power Co [Member]
Jun. 30, 2012
Fuel and Other Consumables Used for Electric Generation [Member]
Southwestern Electric Power Co [Member]
Jun. 30, 2013
Regulatory Assets [Member]
Jun. 30, 2012
Regulatory Assets [Member]
Jun. 30, 2013
Regulatory Assets [Member]
Jun. 30, 2012
Regulatory Assets [Member]
Jun. 30, 2013
Regulatory Assets [Member]
Appalachian Power Co [Member]
Jun. 30, 2012
Regulatory Assets [Member]
Appalachian Power Co [Member]
Jun. 30, 2013
Regulatory Assets [Member]
Appalachian Power Co [Member]
Jun. 30, 2012
Regulatory Assets [Member]
Appalachian Power Co [Member]
Jun. 30, 2013
Regulatory Assets [Member]
Indiana Michigan Power Co [Member]
Jun. 30, 2012
Regulatory Assets [Member]
Indiana Michigan Power Co [Member]
Jun. 30, 2013
Regulatory Assets [Member]
Indiana Michigan Power Co [Member]
Jun. 30, 2012
Regulatory Assets [Member]
Indiana Michigan Power Co [Member]
Jun. 30, 2013
Regulatory Assets [Member]
Ohio Power Co [Member]
Jun. 30, 2012
Regulatory Assets [Member]
Ohio Power Co [Member]
Jun. 30, 2013
Regulatory Assets [Member]
Ohio Power Co [Member]
Jun. 30, 2012
Regulatory Assets [Member]
Ohio Power Co [Member]
Jun. 30, 2013
Regulatory Assets [Member]
Public Service Co Of Oklahoma [Member]
Jun. 30, 2012
Regulatory Assets [Member]
Public Service Co Of Oklahoma [Member]
Jun. 30, 2013
Regulatory Assets [Member]
Public Service Co Of Oklahoma [Member]
Jun. 30, 2012
Regulatory Assets [Member]
Public Service Co Of Oklahoma [Member]
Jun. 30, 2013
Regulatory Assets [Member]
Southwestern Electric Power Co [Member]
Jun. 30, 2012
Regulatory Assets [Member]
Southwestern Electric Power Co [Member]
Jun. 30, 2013
Regulatory Assets [Member]
Southwestern Electric Power Co [Member]
Jun. 30, 2012
Regulatory Assets [Member]
Southwestern Electric Power Co [Member]
Jun. 30, 2013
Regulatory Liabilities [Member]
Jun. 30, 2012
Regulatory Liabilities [Member]
Jun. 30, 2013
Regulatory Liabilities [Member]
Jun. 30, 2012
Regulatory Liabilities [Member]
Jun. 30, 2013
Regulatory Liabilities [Member]
Appalachian Power Co [Member]
Jun. 30, 2012
Regulatory Liabilities [Member]
Appalachian Power Co [Member]
Jun. 30, 2013
Regulatory Liabilities [Member]
Appalachian Power Co [Member]
Jun. 30, 2012
Regulatory Liabilities [Member]
Appalachian Power Co [Member]
Jun. 30, 2013
Regulatory Liabilities [Member]
Indiana Michigan Power Co [Member]
Jun. 30, 2012
Regulatory Liabilities [Member]
Indiana Michigan Power Co [Member]
Jun. 30, 2013
Regulatory Liabilities [Member]
Indiana Michigan Power Co [Member]
Jun. 30, 2012
Regulatory Liabilities [Member]
Indiana Michigan Power Co [Member]
Jun. 30, 2013
Regulatory Liabilities [Member]
Ohio Power Co [Member]
Jun. 30, 2012
Regulatory Liabilities [Member]
Ohio Power Co [Member]
Jun. 30, 2013
Regulatory Liabilities [Member]
Ohio Power Co [Member]
Jun. 30, 2012
Regulatory Liabilities [Member]
Ohio Power Co [Member]
Jun. 30, 2013
Regulatory Liabilities [Member]
Public Service Co Of Oklahoma [Member]
Jun. 30, 2012
Regulatory Liabilities [Member]
Public Service Co Of Oklahoma [Member]
Jun. 30, 2013
Regulatory Liabilities [Member]
Public Service Co Of Oklahoma [Member]
Jun. 30, 2012
Regulatory Liabilities [Member]
Public Service Co Of Oklahoma [Member]
Jun. 30, 2013
Regulatory Liabilities [Member]
Southwestern Electric Power Co [Member]
Jun. 30, 2012
Regulatory Liabilities [Member]
Southwestern Electric Power Co [Member]
Jun. 30, 2013
Regulatory Liabilities [Member]
Southwestern Electric Power Co [Member]
Jun. 30, 2012
Regulatory Liabilities [Member]
Southwestern Electric Power Co [Member]
Commodity:                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                
Power (In MWHs) 553,000,000   553,000,000   498,000,000 99,667,000   99,667,000   94,059,000 68,875,000   68,875,000   64,791,000 140,924,000   140,924,000   132,188,000 9,000   9,000   0 10,000   10,000   0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    
Coal (In Tons) 5,000,000   5,000,000   10,000,000 502,000   502,000   1,401,000 1,607,000   1,607,000   2,711,000 1,372,000   1,372,000   3,033,000 946,000   946,000   1,980,000 795,000   795,000   1,312,000                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    
Natural Gas (In MMBtus) 159,000,000   159,000,000   147,000,000 6,120,000   6,120,000   10,077,000 4,230,000   4,230,000   6,922,000 8,654,000   8,654,000   14,163,000 0   0   0 0   0   0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    
Heating Oil and Gasoline (In Gallons) 5,000,000   5,000,000   6,000,000 883,000   883,000   1,050,000 435,000   435,000   532,000 1,039,000   1,039,000   1,260,000 442,000   442,000   616,000 543,000   543,000   585,000                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    
Interest Rate $ 197,000,000   $ 197,000,000   $ 235,000,000 $ 18,121,000   $ 18,121,000   $ 24,146,000 $ 12,523,000   $ 12,523,000   $ 16,584,000 $ 25,622,000   $ 25,622,000   $ 33,934,000 $ 0   $ 0   $ 0 $ 0   $ 0   $ 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    
Interest Rate and Foreign Currency 874,000,000   874,000,000   1,199,000,000 0   0   0 0   0   200,000,000 0   0   0 0   0   0 0   0   0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    
Cash Collateral Netting                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                
Cash Collateral Received Netted Against Risk Management Assets 8,000,000   8,000,000   7,000,000 555,000   555,000   1,262,000 383,000   383,000   867,000 784,000   784,000   1,774,000 0   0   0 0   0   0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    
Cash Collateral Paid Netted Against Risk Management Liabilities 28,000,000   28,000,000   50,000,000 5,021,000   5,021,000   11,029,000 3,455,000   3,455,000   7,576,000 7,081,000   7,081,000   15,500,000 35,000   35,000   0 44,000   44,000   0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    
Fair Value of Derivative Instruments                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                
Current Risk Management Assets 187,000,000   187,000,000   191,000,000 28,520,000   28,520,000   30,960,000 19,599,000   19,599,000   26,974,000 41,145,000   41,145,000   44,313,000 484,000   484,000   509,000 398,000   398,000   695,000                                                                                     518,000,000 [1] 589,000,000 [1] 86,770,000 [1] 127,645,000 [1] 59,657,000 [1] 93,268,000 [1] 126,809,000 [1] 183,064,000 [1] 1,289,000 [1] 1,657,000 [1] 1,846,000 [1] 2,804,000 [1] 27,000,000 [1] 32,000,000 [1] 995,000 [1] 338,000 [1] 686,000 [1] 220,000 [1] 1,406,000 [1] 464,000 [1] 6,000 [1] 42,000 [1] 6,000 [1] 41,000 [1]                         4,000,000 [1] 3,000,000 [1] 0 [1] 0 [1] 0 [1] 0 [1] 0 [1] 0 [1] 0 [1] 0 [1] 0 [1] 0 [1] 549,000,000 624,000,000 87,765,000 127,983,000 60,343,000 93,488,000 128,215,000 183,528,000 1,295,000 1,699,000 1,852,000 2,845,000 (362,000,000) [2] (433,000,000) [2] (59,245,000) [3] (97,023,000) [3] (40,744,000) [3] (66,514,000) [3] (87,070,000) [3] (139,215,000) [3] (811,000) [3] (1,190,000) [3] (1,454,000) [3] (2,150,000) [3] 187,000,000 [4] 191,000,000 [4] 28,520,000 [4] 30,960,000 [4] 19,599,000 [4] 26,974,000 [4] 41,145,000 [4] 44,313,000 [4] 484,000 [4] 509,000 [4] 398,000 [4] 695,000 [4]                                                                                                                                                                                                                                        
Long-term Risk Management Assets 317,000,000   317,000,000   368,000,000 23,608,000   23,608,000   34,360,000 16,315,000   16,315,000   23,569,000 33,381,000   33,381,000   48,288,000 0   0   31,000                                                                                               449,000,000 [1] 528,000,000 [1] 38,563,000 [1] 60,498,000 [1] 26,650,000 [1] 41,553,000 [1] 54,528,000 [1] 85,023,000 [1] 0 [1] 0 [1] 0 [1] 0 [1] 6,000,000 [1] 5,000,000 [1] 0 [1] 215,000 [1] 0 [1] 148,000 [1] 0 [1] 303,000 [1] 0 [1] 0 [1] 0 [1] 0 [1]                         0 [1] 1,000,000 [1] 0 [1] 0 [1] 0 [1] 0 [1] 0 [1] 0 [1] 0 [1] 0 [1] 0 [1] 0 [1] 455,000,000 534,000,000 38,563,000 60,713,000 26,650,000 41,701,000 54,528,000 85,326,000 0 0 0 0 (138,000,000) [2] (166,000,000) [2] (14,955,000) [3] (26,353,000) [3] (10,335,000) [3] (18,132,000) [3] (21,147,000) [3] (37,038,000) [3] 0 [3] 31,000 [3] 0 [3] 0 [3] 317,000,000 [4] 368,000,000 [4] 23,608,000 [4] 34,360,000 [4] 16,315,000 [4] 23,569,000 [4] 33,381,000 [4] 48,288,000 [4] 0 [4] 31,000 [4] 0 [4] 0 [4]                                                                                                                                                                                                                                        
Total Assets 504,000,000   504,000,000   559,000,000 52,128,000   52,128,000   65,320,000 35,914,000   35,914,000   50,543,000 74,526,000   74,526,000   92,601,000 484,000   484,000   540,000 398,000   398,000   695,000 477,000,000 [5],[6] 517,000,000 [5],[7] 51,558,000 [5],[8] 65,018,000 [5],[8] 35,521,000 [5],[8] 50,343,000 [5],[8] 73,721,000 [5],[8] 92,185,000 [5],[8] 482,000 [5],[8] 515,000 [5],[8] 396,000 [5],[8] 671,000 [5],[8]                                                             967,000,000 [1] 1,117,000,000 [1] 125,333,000 [1] 188,143,000 [1] 86,307,000 [1] 134,821,000 [1] 181,337,000 [1] 268,087,000 [1] 1,289,000 [1] 1,657,000 [1] 1,846,000 [1] 2,804,000 [1] 33,000,000 [1] 37,000,000 [1] 995,000 [1] 553,000 [1] 686,000 [1] 368,000 [1] 1,406,000 [1] 767,000 [1] 6,000 [1] 42,000 [1] 6,000 [1] 41,000 [1]                         4,000,000 [1] 4,000,000 [1] 0 [1] 0 [1] 0 [1] 0 [1] 0 [1] 0 [1] 0 [1] 0 [1] 0 [1] 0 [1] 1,004,000,000 1,158,000,000 126,328,000 188,696,000 86,993,000 135,189,000 182,743,000 268,854,000 1,295,000 1,699,000 1,852,000 2,845,000 (500,000,000) [2] (599,000,000) [2] (74,200,000) [3] (123,376,000) [3] (51,079,000) [3] (84,646,000) [3] (108,217,000) [3] (176,253,000) [3] (811,000) [3] (1,159,000) [3] (1,454,000) [3] (2,150,000) [3] 504,000,000 [4] 559,000,000 [4] 52,128,000 [4] 65,320,000 [4] 35,914,000 [4] 50,543,000 [4] 74,526,000 [4] 92,601,000 [4] 484,000 [4] 540,000 [4] 398,000 [4] 695,000 [4]                                                                                                                                                                                                                                        
Current Risk Management Liabilities 111,000,000   111,000,000   155,000,000 13,397,000   13,397,000   16,698,000 9,387,000   9,387,000   31,517,000 19,769,000   19,769,000   24,155,000 2,111,000   2,111,000   5,848,000 941,000   941,000   1,128,000                                                                                     458,000,000 [1] 546,000,000 [1] 75,377,000 [1] 119,430,000 [1] 52,025,000 [1] 82,433,000 [1] 110,711,000 [1] 171,397,000 [1] 2,910,000 [1] 7,021,000 [1] 2,382,000 [1] 3,261,000 [1] 29,000,000 [1] 43,000,000 [1] 679,000 [1] 1,182,000 [1] 455,000 [1] 807,000 [1] 943,000 [1] 1,658,000 [1] 37,000 [1] 17,000 [1] 45,000 [1] 17,000 [1]                         1,000,000 [1] 35,000,000 [1] 0 [1] 0 [1] 0 [1] 19,524,000 [1] 0 [1] 0 [1] 0 [1] 0 [1] 0 [1] 0 [1] 488,000,000 624,000,000 76,056,000 120,612,000 52,480,000 102,764,000 111,654,000 173,055,000 2,947,000 7,038,000 2,427,000 3,278,000 (377,000,000) [2] (469,000,000) [2] (62,659,000) [3] (103,914,000) [3] (43,093,000) [3] (71,247,000) [3] (91,885,000) [3] (148,900,000) [3] (836,000) [3] (1,190,000) [3] (1,486,000) [3] (2,150,000) [3] 111,000,000 [4] 155,000,000 [4] 13,397,000 [4] 16,698,000 [4] 9,387,000 [4] 31,517,000 [4] 19,769,000 [4] 24,155,000 [4] 2,111,000 [4] 5,848,000 [4] 941,000 [4] 1,128,000 [4]                                                                                                                                                                                                                                        
Long-term Risk Management Liabilities 181,000,000   181,000,000   214,000,000 14,007,000   14,007,000   18,476,000 10,020,000   10,020,000   13,898,000 19,803,000   19,803,000   25,965,000 2,000   2,000   31,000 3,000   3,000   0                                                                                     312,000,000 [1] 383,000,000 [1] 29,990,000 [1] 47,281,000 [1] 21,066,000 [1] 33,714,000 [1] 42,403,000 [1] 66,448,000 [1] 0 [1] 0 [1] 0 [1] 0 [1] 2,000,000 [1] 6,000,000 [1] 24,000 [1] 424,000 [1] 12,000 [1] 292,000 [1] 29,000 [1] 596,000 [1] 12,000 [1] 0 [1] 15,000 [1] 0 [1]                         17,000,000 [1] 6,000,000 [1] 0 [1] 0 [1] 0 [1] 0 [1] 0 [1] 0 [1] 0 [1] 0 [1] 0 [1] 0 [1] 331,000,000 395,000,000 30,014,000 47,705,000 21,078,000 34,006,000 42,432,000 67,044,000 12,000 0 15,000 0 (150,000,000) [2] (181,000,000) [2] (16,007,000) [3] (29,229,000) [3] (11,058,000) [3] (20,108,000) [3] (22,629,000) [3] (41,079,000) [3] (10,000) [3] 31,000 [3] (12,000) [3] 0 [3] 181,000,000 [4] 214,000,000 [4] 14,007,000 [4] 18,476,000 [4] 10,020,000 [4] 13,898,000 [4] 19,803,000 [4] 25,965,000 [4] 2,000 [4] 31,000 [4] 3,000 [4] 0 [4]                                                                                                                                                                                                                                        
Total Liabilities 292,000,000   292,000,000   369,000,000 27,404,000   27,404,000   35,174,000 19,407,000   19,407,000   45,415,000 39,572,000   39,572,000   50,120,000 2,113,000   2,113,000   5,879,000 944,000   944,000   1,128,000 262,000,000 [5],[6] 292,000,000 [5],[7] 27,126,000 [5],[8] 33,819,000 [5],[8] 19,233,000 [5],[8] 24,960,000 [5],[8] 39,201,000 [5],[8] 48,217,000 [5],[8] 2,068,000 [5],[8] 5,879,000 [5],[8] 888,000 [5],[8] 1,128,000 [5],[8]                                                             770,000,000 [1] 929,000,000 [1] 105,367,000 [1] 166,711,000 [1] 73,091,000 [1] 116,147,000 [1] 153,114,000 [1] 237,845,000 [1] 2,910,000 [1] 7,021,000 [1] 2,382,000 [1] 3,261,000 [1] 31,000,000 [1] 49,000,000 [1] 703,000 [1] 1,606,000 [1] 467,000 [1] 1,099,000 [1] 972,000 [1] 2,254,000 [1] 49,000 [1] 17,000 [1] 60,000 [1] 17,000 [1]                         18,000,000 [1] 41,000,000 [1] 0 [1] 0 [1] 0 [1] 19,524,000 [1] 0 [1] 0 [1] 0 [1] 0 [1] 0 [1] 0 [1] 819,000,000 1,019,000,000 106,070,000 168,317,000 73,558,000 136,770,000 154,086,000 240,099,000 2,959,000 7,038,000 2,442,000 3,278,000 (527,000,000) [2] (650,000,000) [2] (78,666,000) [3] (133,143,000) [3] (54,151,000) [3] (91,355,000) [3] (114,514,000) [3] (189,979,000) [3] (846,000) [3] (1,159,000) [3] (1,498,000) [3] (2,150,000) [3] 292,000,000 [4] 369,000,000 [4] 27,404,000 [4] 35,174,000 [4] 19,407,000 [4] 45,415,000 [4] 39,572,000 [4] 50,120,000 [4] 2,113,000 [4] 5,879,000 [4] 944,000 [4] 1,128,000 [4]                                                                                                                                                                                                                                        
Total MTM Derivative Contract Net Assets (Liabilities)                                                                                                                                                 197,000,000 [1] 188,000,000 [1] 19,966,000 [1] 21,432,000 [1] 13,216,000 [1] 18,674,000 [1] 28,223,000 [1] 30,242,000 [1] (1,621,000) [1] (5,364,000) [1] (536,000) [1] (457,000) [1] 2,000,000 [1] (12,000,000) [1] 292,000 [1] (1,053,000) [1] 219,000 [1] (731,000) [1] 434,000 [1] (1,487,000) [1] (43,000) [1] 25,000 [1] (54,000) [1] 24,000 [1]                         (14,000,000) [1] (37,000,000) [1] 0 [1] 0 [1] 0 [1] (19,524,000) [1] 0 [1] 0 [1] 0 [1] 0 [1] 0 [1] 0 [1] 185,000,000 139,000,000 20,258,000 20,379,000 13,435,000 (1,581,000) 28,657,000 28,755,000 (1,664,000) (5,339,000) (590,000) (433,000) 27,000,000 [2] 51,000,000 [2] 4,466,000 [3] 9,767,000 [3] 3,072,000 [3] 6,709,000 [3] 6,297,000 [3] 13,726,000 [3] 35,000 [3] 0 [3] 44,000 [3] 0 [3] 212,000,000 [4] 190,000,000 [4] 24,724,000 [4] 30,146,000 [4] 16,507,000 [4] 5,128,000 [4] 34,954,000 [4] 42,481,000 [4] (1,629,000) [4] (5,339,000) [4] (546,000) [4] (433,000) [4]                                                                                                                                                                                                                                        
Amount of Gain (Loss) Recognized on Risk Management Contracts                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                
Amount of Gain (Loss) Recognized on Risk Management Contracts 17,000,000 5,000,000 35,000,000 11,000,000   450,000 316,000 663,000 2,917,000   432,000 66,000 683,000 6,495,000   687,000 821,000 1,196,000 6,183,000   360,000 (618,000) 2,418,000 (5,797,000)   (32,000) (88,000) 363,000 (6,845,000)                                                                                                                                                                                                                                                               5,000,000 4,000,000 13,000,000 14,000,000 194,000 (599,000) 873,000 (926,000) 2,897,000 2,579,000 7,844,000 5,392,000 1,819,000 2,538,000 3,533,000 11,031,000 169,000 165,000 216,000 160,000 302,000 303,000 330,000 252,000 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 16,000,000 5,000,000 30,000,000 8,000,000 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0                                                                                                
Amount of Gain (Loss) Recognized on Risk Management Contracts                                                                                                                                                                                                                                                                                                                                                                                                                                                                 (8,000,000) [9] (17,000,000) [9] (5,000,000) [9] (38,000,000) [9] (974,000) [9] (3,796,000) [9] 0 [9] (7,277,000) [9] (1,585,000) [9] (2,905,000) [9] (1,099,000) [9] (6,015,000) [9] (4,492,000) [9] (8,895,000) [9] (5,697,000) [9] (12,026,000) [9] 192,000 [9] (757,000) [9] 2,202,000 [9] (5,958,000) [9] (373,000) [9] (364,000) [9] (102,000) [9] (7,092,000) [9] 4,000,000 [9] 13,000,000 [9] (3,000,000) [9] 27,000,000 [9] 1,230,000 [9] 4,711,000 [9] (210,000) [9] 11,120,000 [9] (880,000) [9] 392,000 [9] (6,062,000) [9] 7,118,000 [9] 3,360,000 [9] 7,178,000 [9] 3,360,000 [9] 7,178,000 [9] (1,000) [9] (26,000) [9] 0 [9] 1,000 [9] 39,000 [9] (27,000) [9] 135,000 [9] (5,000) [9]
Impact of Cash Flow Hedges on the Condensed Balance Sheet                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                
Hedging Assets 14,000,000 [10]   14,000,000 [10]   24,000,000 [10]                                                                                                               14,000,000 [10] 24,000,000 [10] 570,000 [10] 302,000 [10] 393,000 [10] 200,000 [10] 805,000 [10] 416,000 [10] 2,000 [10] 25,000 [10] 2,000 [10] 24,000 [10]                                                 0 [10] 0 [10] 0 [10] 0 [10] 0 [10] 0 [10] 0 [10] 0 [10] 0 [10] 0 [10] 0 [10] 0 [10]                                                                                                                                                                                                                                                                                                                                        
Hedging Liabilities 14,000,000 [10]   14,000,000 [10]   73,000,000 [10]                                                                                                               12,000,000 [10] 36,000,000 [10] 278,000 [10] 1,355,000 [10] 174,000 [10] 931,000 [10] 371,000 [10] 1,903,000 [10] 45,000 [10] 0 [10] 56,000 [10] 0 [10]                                                 2,000,000 [10] 37,000,000 [10] 0 [10] 0 [10] 0 [10] 19,524,000 [10] 0 [10] 0 [10] 0 [10] 0 [10] 0 [10] 0 [10]                                                                                                                                                                                                                                                                                                                                        
AOCI Gain (Loss) Net of Tax (24,000,000)   (24,000,000)   (38,000,000)                                                                           (44,000,000) (34,000,000) (23,000,000) (258,000) (824,000) (285,000) (20,261,000) (12,828,000) (15,284,000) 6,135,000 5,965,000 7,706,000 6,737,000 7,096,000 7,149,000 (16,903,000) (17,299,000) (15,524,000) 1,000,000 (8,000,000) 197,000 (644,000) 147,000 (446,000) 289,000 (912,000) (21,000) 21,000 (26,000) 22,000                                                 (25,000,000) (30,000,000) 2,583,000 2,077,000 (16,796,000) (19,647,000) 7,415,000 8,095,000 6,081,000 6,460,000 (14,437,000) (15,571,000)                                                                                                                                                                                                                                                                                                                                        
Portion Expected to be Reclassified to Net Income During the Next Twelve Months     (6,000,000)   (12,000,000)                                                                                                               (2,000,000) (8,000,000) 213,000 (507,000) 153,000 (355,000) 308,000 (720,000) (13,000) 21,000 (17,000) 22,000                                                 (4,000,000) (4,000,000) (1,013,000) (1,013,000) (1,640,000) (1,600,000) 1,359,000 1,359,000 759,000 759,000 (2,267,000) (2,267,000)                                                                                                                                                                                                                                                                                                                                        
Maximum Term for Exposure to Variability of Future Cash Flows     27 months         18 months         18 months         18 months         18 months         18 months                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        
Collateral Triggering Events [Abstract]                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                
Liabilities for Derivative Contracts with Credit Downgrade Triggers 4,000,000   4,000,000   7,000,000 937,000   937,000   2,159,000 647,000   647,000   1,483,000 1,324,000   1,324,000   3,034,000 0   0   0 0   0   0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    
Amount of Collateral AEP Subsidiaries Would Have Been Required to Post 48,000,000   48,000,000   32,000,000 6,147,000   6,147,000   3,699,000 4,248,000   4,248,000   2,540,000 8,692,000   8,692,000   5,198,000 1,533,000   1,533,000   1,509,000 1,810,000   1,810,000   1,778,000                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    
Amount Attributable to RTO and ISO Activities 47,000,000   47,000,000   31,000,000 6,074,000   6,074,000   3,510,000 4,197,000   4,197,000   2,411,000 8,588,000   8,588,000   4,933,000 1,306,000   1,306,000   1,429,000 1,542,000   1,542,000   1,683,000                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    
Liabilities for Contracts with Cross Default Provisions Prior to Contractural Netting Arrangements 360,000,000   360,000,000   469,000,000 31,949,000   31,949,000   49,465,000 22,079,000   22,079,000   53,499,000 45,175,000   45,175,000   69,516,000 15,000   15,000   0 18,000   18,000   0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    
Amount of Cash Collateral Posted 3,000,000   3,000,000   8,000,000 0   0   1,822,000 0   0   1,252,000 0   0   2,561,000 0   0   0 0   0   0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    
Additional Settlement Liability if Cross Default Provision is Triggered 252,000,000   252,000,000   328,000,000 24,748,000   24,748,000   30,160,000 17,102,000   17,102,000   40,240,000 34,993,000   34,993,000   42,386,000 14,000   14,000   0 17,000   17,000   0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    
Derivatives and Hedging (Textuals) [Abstract]                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                
Cash Collateral Received Netted Against Risk Management Assets 8,000,000   8,000,000   7,000,000 555,000   555,000   1,262,000 383,000   383,000   867,000 784,000   784,000   1,774,000 0   0   0 0   0   0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    
Cash Collateral Paid Netted Against Risk Management Liabilities 28,000,000   28,000,000   50,000,000 5,021,000   5,021,000   11,029,000 3,455,000   3,455,000   7,576,000 7,081,000   7,081,000   15,500,000 35,000   35,000   0 44,000   44,000   0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    
Maximum Term for Exposure to Variability of Future Cash Flows     27 months         18 months         18 months         18 months         18 months         18 months                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        
Gain (Loss) on Fair Value Hedging Instrument 11,000,000 1,000,000 12,000,000 2,000,000                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        
Gain (Loss) on Fair Value Portion of Long Term Debt $ 11,000,000 $ 1,000,000 $ 12,000,000 $ 2,000,000                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        
[1] Derivative instruments within these categories are reported gross. These instruments are subject to master netting agreements and are presented on the condensed balance sheets on a net basis in accordance with the accounting guidance for "Derivatives and Hedging."
[2] Amounts primarily include counterparty netting of risk management and hedging contracts and associated cash collateral in accordance with the accounting guidance for "Derivatives and Hedging." Amounts also include de-designated risk management contracts.
[3] Amounts include counterparty netting of risk management and hedging contracts and associated cash collateral in accordance with the accounting guidance for "Derivatives and Hedging."
[4] There are no derivative contracts subject to a master netting arrangement or similar agreement which are not offset in the statement of financial position.
[5] Amounts in ''Other'' column primarily represent counterparty netting of risk management and hedging contracts and associated cash collateral under the accounting guidance for ''Derivatives and Hedging.''
[6] The June 30, 2013 maturity of the net fair value of risk management contracts prior to cash collateral, assets/(liabilities), is as follows: Level 1 matures $3 million in 2013, ($3) million in periods 2014-2016 and ($4) million in periods 2017-2018; Level 2 matures $12 million in 2013, $53 million in periods 2014-2016, $8 million in periods 2017-2018 and $6 million in periods 2019-2030; Level 3 matures $19 million in 2013, $50 million in periods 2014-2016, $30 million in periods 2017-2018 and $23 million in periods 2019-2030. Risk management commodity contracts are substantially comprised of power contracts.
[7] The December 31, 2012 maturity of the net fair value of risk management contracts prior to cash collateral, assets/(liabilities), is as follows: Level 1 matures $9 million in 2013, ($3) million in periods 2014-2016 and ($4) million in periods 2017-2018; Level 2 matures $16 million in 2013, $61 million in periods 2014-2016, $16 million in periods 2017-2018 and $7 million in periods 2019-2030; Level 3 matures $18 million in 2013, $31 million in periods 2014-2016, $13 million in periods 2017-2018 and $24 million in periods 2019-2030. Risk management commodity contracts are substantially comprised of power contracts.
[8] Substantially comprised of power contracts for APCo, I&M and OPCo and coal contracts for PSO and SWEPCo.
[9] Represents realized and unrealized gains and losses subject to regulatory accounting treatment recorded as either current or noncurrent on the condensed balance sheets.
[10] Hedging Assets and Hedging Liabilities are included in Risk Management Assets and Liabilities on the condensed balance sheets.