Rate Matters - East Companies (Details) (USD $)									9 Months Ended								9 Months Ended																		1 Months Ended							9 Months Ended										9 Months Ended
	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2014 Appalachian Power Co [Member]	Dec. 31, 2013 Appalachian Power Co [Member]	Sep. 30, 2014 Indiana Michigan Power Co [Member]	Dec. 31, 2013 Indiana Michigan Power Co [Member]	Sep. 30, 2014 Ohio Power Co [Member]	Dec. 31, 2013 Ohio Power Co [Member]	Sep. 30, 2014 Cook Plant Life Cycle Management Project [Member]	Sep. 30, 2014 Cook Plant Life Cycle Management Project [Member] Indiana Michigan Power Co [Member]	Sep. 30, 2014 Indiana Base Rate Case [Member]	Sep. 30, 2014 Indiana Base Rate Case [Member] Indiana Michigan Power Co [Member]	Sep. 30, 2014 Ohio Electric Security Plan Filing [Member]	Sep. 30, 2014 Ohio Electric Security Plan Filing [Member] Ohio Power Co [Member]	Sep. 30, 2014 Ohio Electric Security Plan Filing [Member] Deferred Fuel Costs [Member]	Sep. 30, 2014 Ohio Electric Security Plan Filing [Member] Deferred Fuel Costs [Member] Ohio Power Co [Member]	Sep. 30, 2014 Ohio Fuel Adjustment Clause Audit - 2009 [Member]	Sep. 30, 2014 Ohio Fuel Adjustment Clause Audit - 2009 [Member] Ohio Power Co [Member]	Sep. 30, 2014 Ohio IGCC Plant [Member]	Sep. 30, 2014 Ohio IGCC Plant [Member] Ohio Power Co [Member]	Sep. 30, 2014 Plant Transfer [Member]	Sep. 30, 2014 Plant Transfer [Member] Appalachian Power Co [Member]	Sep. 30, 2014 Special Rate Mechanism For Ormet [Member]	Sep. 30, 2014 Special Rate Mechanism For Ormet [Member] Ohio Power Co [Member]	Sep. 30, 2014 Virginia Biennial Base Rate Case [Member]	Sep. 30, 2014 Virginia Biennial Base Rate Case [Member] Appalachian Power Co [Member]	Sep. 30, 2014 Virginia Transmission Rate Adjustment Clause [Member]	Sep. 30, 2014 Virginia Transmission Rate Adjustment Clause [Member] Appalachian Power Co [Member]	Sep. 30, 2014 West Virginia Base Rate Case [Member]	Sep. 30, 2014 West Virginia Base Rate Case [Member] Appalachian Power Co [Member]	Sep. 30, 2014 Deferred Capacity Costs [Member] Ohio Electric Security Plan Filing [Member]	Sep. 30, 2014 Deferred Capacity Costs [Member] Ohio Electric Security Plan Filing [Member] Ohio Power Co [Member]	Sep. 30, 2014 Storm Costs [Member] Storm Damage Recovery Rider [Member]	Sep. 30, 2014 Storm Costs [Member] Storm Damage Recovery Rider [Member] Ohio Power Co [Member]	Oct. 23, 2014 Subsequent Event [Member] Ohio Electric Security Plan Filing [Member]	Oct. 23, 2014 Subsequent Event [Member] Ohio Electric Security Plan Filing [Member] Ohio Power Co [Member]	Oct. 23, 2014 Subsequent Event [Member] Plant Transfer [Member]	Oct. 23, 2014 Subsequent Event [Member] Plant Transfer [Member] Appalachian Power Co [Member]	Oct. 23, 2014 Subsequent Event [Member] Transmission Distribution and Storage System Improvement Charge (TDSIC) [Member]	Oct. 23, 2014 Subsequent Event [Member] Transmission Distribution and Storage System Improvement Charge (TDSIC) [Member] Indiana Michigan Power Co [Member]	Oct. 23, 2014 Subsequent Event [Member] Kentucky Fuel Adjustment Clause Review [Member]	Sep. 30, 2014 Applicable to FERC Jurisdiction [Member] APCo's Filing for IGCC Plant [Member]	Sep. 30, 2014 Applicable to FERC Jurisdiction [Member] APCo's Filing for IGCC Plant [Member] Appalachian Power Co [Member]	Sep. 30, 2014 Applicable to Virginia Jurisdiction [Member] APCo's Filing for IGCC Plant [Member]	Sep. 30, 2014 Applicable to Virginia Jurisdiction [Member] APCo's Filing for IGCC Plant [Member] Appalachian Power Co [Member]	Sep. 30, 2014 Applicable to West Virginia Jurisdiction [Member] APCo's Filing for IGCC Plant [Member]	Sep. 30, 2014 Applicable to West Virginia Jurisdiction [Member] APCo's Filing for IGCC Plant [Member] Appalachian Power Co [Member]	Sep. 30, 2014 Indiana Filing [Member] Cook Plant Life Cycle Management Project [Member]	Sep. 30, 2014 Indiana Filing [Member] Cook Plant Life Cycle Management Project [Member] Indiana Michigan Power Co [Member]	Sep. 30, 2014 Terms Of Kentucky Power Co Memorandum Of Understanding [Member] Plant Transfer [Member]	Sep. 30, 2014 Big Sandy Plant Unit 2 [Member]	Sep. 30, 2014 Big Sandy Plant, Unit 1 Natural Gas Conversion [Member] Terms Of Kentucky Power Co Memorandum Of Understanding [Member] Plant Transfer [Member]	Sep. 30, 2014 Minimum [Member] Virginia Biennial Base Rate Case [Member]	Sep. 30, 2014 Minimum [Member] Virginia Biennial Base Rate Case [Member] Appalachian Power Co [Member]	Sep. 30, 2014 Maximum [Member] Virginia Biennial Base Rate Case [Member]	Sep. 30, 2014 Maximum [Member] Virginia Biennial Base Rate Case [Member] Appalachian Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent	$ 4,308,000,000	$ 4,376,000,000	$ 1,003,018,000	$ 1,003,890,000	$ 513,387,000	$ 524,114,000	$ 1,370,561,000	$ 1,378,697,000							$ 395,000,000	$ 395,000,000															$ 409,000,000	$ 409,000,000
Potential Refund of Carrying Costs Due to Accumulated Deferred Income Tax Credit													28,000,000	28,000,000
Potential Refund of Unrecognized Equity Carrying Costs Due to Accumulated Deferred Income Tax Credit													14,000,000	14,000,000
PUCO-ordered Fixed Price per MW Day for Customers Who Switch During ESP Period													188.88	188.88
Reliability Pricing Model Rate per MW Day in Effect through May 2014													34	34
Reliability Pricing Model Rate per MW Day in Effect from June 2014 through May 2015													150	150
Retail Stability Rider through May 2014 ($ Per MWh)													3.50	3.50
Retail Stability Rider for the Period June 2014 through May 2015 ($ per MWh)													4.00	4.00
Amount of Retail Stability Rider Applied to the Deferred Capacity Costs ($ per MWh)													1.00	1.00
Percentage of Standard Service Offer Load Which Registrant Will Conduct an Energy Only Auction for Delivery through May 2015													10.00%	10.00%
Additional Percentage of Standard Service Offer Load Which Registrant Conducted an Energy Only Auction for Delivery Beginning November 2014 through May 2015													50.00%	50.00%
Remaining Percentage of Standard Service Offer Load Which Registrant Will Conduct an Energy Only Auction for Delivery from January 2015 through May 2015													40.00%	40.00%
Annual Retail Share of Fixed Fuel Costs																																			90,000,000	90,000,000
Requested Return on Equity on Capital Costs for Certain Riders													10.65%	10.65%
Estimated Average Decrease in Customer Rates Over Three Years													9.00%	9.00%
Intended Retail Stability Rider Rate to be Continued Until Capacity Deferral Balance is Collected ($ per MWh)													4.00	4.00
Future Commitment to Support the Development of a Large Solar Farm													20,000,000	20,000,000
Recommended Amount of Storm Cost Recovery as Approved in Stipulation Agreement																																	55,000,000	55,000,000
2008 Coal Contract Settlement Proceeds to be Applied to Deferred Fuel Balance as Originally Ordered by the PUCO																	65,000,000	65,000,000
Net Favorable Fuel Adjustment Recorded in 2012 Based on Fuel Adjustment Clause Audit Rehearing																	30,000,000	30,000,000
Maximum Amount of Ormet's October and November 2012 Unpaid Balance Allowed to be Recovered in the Economic Development Rider																							20,000,000	20,000,000
Amount of Foregone Revenues to be Collected Through the Economic Development Rider as Proposed in the Stipulation Agreement																							49,000,000	49,000,000
Amount of Foregone Revenues to be Collected Through the Economic Development Rider as Approved in the Economic Development Rider Filing																							39,000,000	39,000,000
Remaining Ormet Deferral Allowed to be Requested Upon PUCO Adoption of Ormet Stipulation Agreement																							10,000,000	10,000,000
Amount of Remaining Foregone Revenues Objected to by an Intervenor																							5,000,000	5,000,000
Deferred Fuel Adjustment Clause Related to Ormet Interim Arrangement as of September 2009																							64,000,000	64,000,000
Unrecognized Equity Carrying Costs Related to Ormet Interim Arrangement as of September 2009																							2,000,000	2,000,000
Collection of Authorized Pre-Construction Costs																			24,000,000	24,000,000
Proposed Base Rate Surcharge																					113,000,000	113,000,000
Intervenor Proposed Base Rate Surcharge																					87,000,000	87,000,000
Amount to be Paid by WPCo for Certain Assets Excluded from the Net Book Value of the Plant Transfer as Proposed in the Stipulation Agreement																																					20,000,000	20,000,000
Percentage of Associated Costs to be Reflected in Rates Upon Transfer of the Plant as Proposed in Stipulation Agreement																																					82.50%	82.50%
Remaining Percentage of Associated Costs to be Reflected in Rates by 2020 as Proposed in the Stipulation Agreement																																					17.50%	17.50%
Percentage of Plants Output in Which WPCo will Share Energy Margins with Ratepayers as Proposed in Stipulation Agreement																																					82.50%	82.50%
Remaining Percentage of Plants Output in Which WPCo will Retain All Energy Margins Through 2020 as Proposed in Stipulation Agreement																																					17.50%	17.50%
Amount of Deferred Preconstruction IGCC Costs for Future Recovery																																										2,000,000	2,000,000	10,000,000	10,000,000	9,000,000	9,000,000
Intervenor Recommended Write-Off of IGCC Costs																																												10,000,000	10,000,000
Requested Increase in Virginia Transmission RAC Revenues																											50,000,000	50,000,000
Annual Revenue Increase as Approved in Stipulation Agreement																											49,000,000	49,000,000
Approved Return On Equity											10.20%	10.20%													10.90%	10.90%
Requested Annual Amortization of Certain Deferred Costs																									7,000,000	7,000,000			89,000,000	77,000,000
Intervenor Recommended Refund to Customers Range																																																					15,000,000	15,000,000	22,000,000	22,000,000
Intervenor Recommended Write-Off of Certain APCo Assets																									27,000,000	27,000,000
Intervenor Recommended Annual Increase In Depreciation Expense																									38,000,000	38,000,000
Requested Base Rate Increase																													181,000,000	156,000,000
Requested Return on Equity																													10.62%	10.62%
Requested Annual Vegetation Management Rider																													45,000,000	38,000,000
Approved Base Rate Increase											85,000,000	85,000,000
Approved Base Rate Increase Adjustment											92,000,000	92,000,000
Amount of Prepaid Pension Asset in Rate Base Opposed by Internvenor on Appeal											7,000,000	7,000,000
Projected Capital Costs									1,200,000,000	1,200,000,000																																										60,000,000
Construction Work in Progress	3,283,000,000	2,471,000,000	253,928,000	184,701,000	561,440,000	427,164,000	238,195,000	185,428,000	492,000,000	492,000,000
Amount Excluded From Indiana Utility Regulatory Commission LCM Project Approval																																																23,000,000	23,000,000
Estimated Cost Of Capital Improvements And Associated Operation And Maintenance Expenses																																							787,000,000	787,000,000
Percentage Of Approved Project Costs To Be Included In Proposed Rider																																							80.00%	80.00%
Remaining Percentage Of Approved Project Costs To Be Included In Next General Rate Case																																							20.00%	20.00%
Property, Plant and Equipment, Net																																																			273,000,000
Annual Amount Of Asset Transfer Rider																																																		44,000,000
Annual Level Of Off System Sales Margins In Base Rates Above Which Is Retained By Kentucky Power Company																																																		15,300,000
Intervenor Recommended Refund To Customers																																									$ 13,000,000