Rate Matters - East Companies (Details) (USD $)	3 Months Ended	1 Months Ended
	Mar. 31, 2015	Apr. 23, 2015	Dec. 31, 2014
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent	$ 4,255,000,000		$ 4,264,000,000
Appalachian Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent	842,030,000		857,872,000
Indiana Michigan Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent	534,898,000		536,152,000
Ohio Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent	1,261,382,000		1,318,939,000
Kentucky Base Rate Case - 2014 [Member]
Public Utilities, General Disclosures [Line Items]
Requested Return on Equity	10.62%
Requested Net Increase In Rates	70,000,000
Requested Increase In Rider Rates	75,000,000
Requested Decrease In Annual Base Rates	5,000,000
Kentucky Fuel Adjustment Clause Review [Member]
Public Utilities, General Disclosures [Line Items]
Amount Of Regulatory Disallowance Resulting From Commission Order	36,000,000
Ohio Electric Security Plan Filing [Member]
Public Utilities, General Disclosures [Line Items]
Potential Refund of Carrying Costs Due to Accumulated Deferred Income Tax Credit	25,000,000
Potential Refund of Unrecognized Equity Carrying Costs Due to Accumulated Deferred Income Tax Credit	13,000,000
PUCO-ordered Fixed Price per MW Day for Customers Who Switch During ESP Period	188.88
Reliability Pricing Model Rate per MW Day in Effect through May 2014	34
Reliability Pricing Model Rate per MW Day in Effect from June 2014 through May 2015	150
Retail Stability Rider through May 2014 ($ Per MWh)	3.50
Retail Stability Rider for the Period June 2014 through May 2015 ($ per MWh)	4.00
Amount of Retail Stability Rider Applied to the Deferred Capacity Costs ($ per MWh)	1.00
Intended Retail Stability Rider Rate to be Continued Until Capacity Deferral Balance is Collected ($ per MWh)	4.00
Percentage of Standard Service Offer Load Which Registrant Conducted Energy Only Auctions for Delivery from April 2014 through May 2015	100.00%
Annual Retail Share of Fixed Fuel Costs	90,000,000
Requested Return on Equity on Capital Costs for Certain Riders	10.65%
Approved Return On Equity	10.20%
Future Commitment to Support the Development of a Large Solar Farm	20,000,000
Ohio Electric Security Plan Filing [Member] | Ohio Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Potential Refund of Carrying Costs Due to Accumulated Deferred Income Tax Credit	25,000,000
Potential Refund of Unrecognized Equity Carrying Costs Due to Accumulated Deferred Income Tax Credit	13,000,000
PUCO-ordered Fixed Price per MW Day for Customers Who Switch During ESP Period	188.88
Reliability Pricing Model Rate per MW Day in Effect through May 2014	34
Reliability Pricing Model Rate per MW Day in Effect from June 2014 through May 2015	150
Retail Stability Rider through May 2014 ($ Per MWh)	3.50
Retail Stability Rider for the Period June 2014 through May 2015 ($ per MWh)	4.00
Amount of Retail Stability Rider Applied to the Deferred Capacity Costs ($ per MWh)	1.00
Intended Retail Stability Rider Rate to be Continued Until Capacity Deferral Balance is Collected ($ per MWh)	4.00
Percentage of Standard Service Offer Load Which Registrant Conducted Energy Only Auctions for Delivery from April 2014 through May 2015	100.00%
Annual Retail Share of Fixed Fuel Costs	90,000,000
Requested Return on Equity on Capital Costs for Certain Riders	10.65%
Approved Return On Equity	10.20%
Future Commitment to Support the Development of a Large Solar Farm	20,000,000
Ohio Fuel Adjustment Clause Audit - 2009 [Member]
Public Utilities, General Disclosures [Line Items]
2008 Coal Contract Settlement Proceeds to be Applied to Deferred Fuel Balance as Originally Ordered by the PUCO	65,000,000
Net Favorable Fuel Adjustment Recorded in 2012 Based on Fuel Adjustment Clause Audit Rehearing	30,000,000
Ohio Fuel Adjustment Clause Audit - 2009 [Member] | Ohio Power Co [Member]
Public Utilities, General Disclosures [Line Items]
2008 Coal Contract Settlement Proceeds to be Applied to Deferred Fuel Balance as Originally Ordered by the PUCO	65,000,000
Net Favorable Fuel Adjustment Recorded in 2012 Based on Fuel Adjustment Clause Audit Rehearing	30,000,000
Special Rate Mechanism For Ormet [Member]
Public Utilities, General Disclosures [Line Items]
Amount of Foregone Revenues to be Collected Through the Economic Development Rider as Approved in the Economic Development Rider Filing	39,000,000
Remaining Ormet Deferral Allowed to be Requested Upon PUCO Adoption of Ormet Stipulation Agreement	10,000,000
Amount of Remaining Foregone Revenues Objected to by an Intervenor	5,000,000
Deferred Fuel Adjustment Clause Related to Ormet Interim Arrangement as of September 2009	64,000,000
Unrecognized Equity Carrying Costs Related to Ormet Interim Arrangement as of September 2009	2,000,000
Special Rate Mechanism For Ormet [Member] | Ohio Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Amount of Foregone Revenues to be Collected Through the Economic Development Rider as Approved in the Economic Development Rider Filing	39,000,000
Remaining Ormet Deferral Allowed to be Requested Upon PUCO Adoption of Ormet Stipulation Agreement	10,000,000
Amount of Remaining Foregone Revenues Objected to by an Intervenor	5,000,000
Deferred Fuel Adjustment Clause Related to Ormet Interim Arrangement as of September 2009	64,000,000
Unrecognized Equity Carrying Costs Related to Ormet Interim Arrangement as of September 2009	2,000,000
Transmission Distribution and Storage System Improvement Charge (TDSIC) [Member]
Public Utilities, General Disclosures [Line Items]
Estimated Cost Of Capital Improvements And Associated Operation And Maintenance Expenses	787,000,000
Percentage Of Approved Project Costs To Be Included In Proposed Rider	80.00%
Remaining Percentage Of Approved Project Costs To Be Included In Next General Rate Case	20.00%
Transmission Distribution and Storage System Improvement Charge (TDSIC) [Member] | Indiana Michigan Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Estimated Cost Of Capital Improvements And Associated Operation And Maintenance Expenses	787,000,000
Percentage Of Approved Project Costs To Be Included In Proposed Rider	80.00%
Remaining Percentage Of Approved Project Costs To Be Included In Next General Rate Case	20.00%
Virginia Regulatory Asset Proceeding - 2015 [Member]
Public Utilities, General Disclosures [Line Items]
Amounts Of Regulatory Assets Under Review In Separate Proceeding	14,000,000
Virginia Regulatory Asset Proceeding - 2015 [Member] | Appalachian Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Amounts Of Regulatory Assets Under Review In Separate Proceeding	14,000,000
West Virginia Base Rate Case [Member]
Public Utilities, General Disclosures [Line Items]
Requested Base Rate Increase	181,000,000
Requested Return on Equity	10.62%
Requested Annual Amortization of Certain Deferred Costs	89,000,000
Requested Annual Vegetation Management Rider	45,000,000
Additional Intervenors Recommended Return On Common Equity	8.70%
Additional Intervenors Recommended Regulatory Disallowance	89,000,000
Intervenors Recommended Disallowance Related To Amos Plant Transfer	44,000,000
West Virginia Base Rate Case [Member] | Appalachian Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Requested Base Rate Increase	156,000,000
Requested Return on Equity	10.62%
Requested Annual Amortization of Certain Deferred Costs	77,000,000
Requested Annual Vegetation Management Rider	38,000,000
Additional Intervenors Recommended Return On Common Equity	8.70%
Additional Intervenors Recommended Regulatory Disallowance	77,000,000
Intervenors Recommended Disallowance Related To Amos Plant Transfer	38,000,000
Deferred Capacity Costs [Member] | Ohio Electric Security Plan Filing [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent	434,000,000
Deferred Capacity Costs [Member] | Ohio Electric Security Plan Filing [Member] | Ohio Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent	434,000,000
Subsequent Event [Member] | Ohio Electric Security Plan Filing [Member]
Public Utilities, General Disclosures [Line Items]
Retail Stability Rider Rate to be Continued Until Capacity Deferral Balance is Collected as Ordered by the PUCO ($ per MWh)		4.00
Deferred Capacity Costs Recovery Period as Ordered by PUCO (in months)		32 months
Subsequent Event [Member] | Ohio Electric Security Plan Filing [Member] | Ohio Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Retail Stability Rider Rate to be Continued Until Capacity Deferral Balance is Collected as Ordered by the PUCO ($ per MWh)		4.00
Deferred Capacity Costs Recovery Period as Ordered by PUCO (in months)		32 months
Subsequent Event [Member] | Transmission Distribution and Storage System Improvement Charge (TDSIC) [Member]
Public Utilities, General Disclosures [Line Items]
Reduction to the Estimated Cost of Capital Improvements and Associated Operation and Maintenance Expenses		117,000,000
Subsequent Event [Member] | Transmission Distribution and Storage System Improvement Charge (TDSIC) [Member] | Indiana Michigan Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Reduction to the Estimated Cost of Capital Improvements and Associated Operation and Maintenance Expenses		117,000,000
Tanners Creek Plant, Units 1 - 4 [Member]
Public Utilities, General Disclosures [Line Items]
Property, Plant and Equipment, Net	333,000,000
Tanners Creek Plant, Units 1 - 4 [Member] | Indiana Michigan Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Property, Plant and Equipment, Net	333,000,000
Minimum [Member] | Kentucky Base Rate Case - 2014 [Member]
Public Utilities, General Disclosures [Line Items]
Intervenor Recommended Return On Common Equity	8.65%
Intervenor Recommended Net Increase to Rates	20,000,000
Intervenor Recommended Increase to Rider Rates	55,000,000
Intervenor Recommended Decrease In Annual Base Rates	35,000,000
Minimum [Member] | West Virginia Base Rate Case [Member]
Public Utilities, General Disclosures [Line Items]
Intervenor Recommended Increase To Annual Revenue	35,000,000
Intervenor Recommended Return On Common Equity	9.00%
Intervenor Recommended Regulatory Disallowance	7,000,000
Minimum [Member] | West Virginia Base Rate Case [Member] | Appalachian Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Intervenor Recommended Increase To Annual Revenue	30,000,000
Intervenor Recommended Return On Common Equity	9.00%
Intervenor Recommended Regulatory Disallowance	6,000,000
Maximum [Member] | Kentucky Base Rate Case - 2014 [Member]
Public Utilities, General Disclosures [Line Items]
Intervenor Recommended Return On Common Equity	8.75%
Intervenor Recommended Net Increase to Rates	26,000,000
Intervenor Recommended Increase to Rider Rates	63,000,000
Intervenor Recommended Decrease In Annual Base Rates	37,000,000
Maximum [Member] | West Virginia Base Rate Case [Member]
Public Utilities, General Disclosures [Line Items]
Intervenor Recommended Increase To Annual Revenue	59,000,000
Intervenor Recommended Return On Common Equity	10.00%
Intervenor Recommended Regulatory Disallowance	9,000,000
Maximum [Member] | West Virginia Base Rate Case [Member] | Appalachian Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Intervenor Recommended Increase To Annual Revenue	51,000,000
Intervenor Recommended Return On Common Equity	10.00%
Intervenor Recommended Regulatory Disallowance	$ 8,000,000