Commitments, Guarantees and Contingencies (Details) (USD $)	3 Months Ended
	Mar. 31, 2015
Letters of Credit [Member]
Maximum Future Payments for Letters of Credit [Abstract]
Maximum Future Payments for Letters of Credit	$ 75,000,000
Pollution Control Bonds Supported by Bilateral Letters of Credit [Abstract]
Variable Rate PCBs Supported	477,000,000
Bilateral Letters of Credit	483,000,000
Commitments, Guarantees and Contingencies (Textuals) [Abstract]
Revolving Credit Facilities	3,500,000,000
Letters of Credit Limit	1,200,000,000
Maximum Future Payments for Letters of Credit	75,000,000
Uncommitted Facility	100,000,000
Maximum Future Payments for Letters of Credit Issued Under the Uncommitted Facility	100,000,000
Variable Rate PCBs Supported	477,000,000
Bilateral Letters of Credit	483,000,000
Master Lease Agreements [Member]
Maximum Potential Loss on Master Lease Agreements [Abstract]
Max Potential Loss on Master Lease Agreements	26,000,000
Commitments, Guarantees and Contingencies (Textuals) [Abstract]
Max Potential Loss on Master Lease Agreements	26,000,000
Guarantees of Third Party Obligations [Member]
Commitments, Guarantees and Contingencies (Textuals) [Abstract]
Guarantees of Mine Reclamation, Amount	115,000,000
Estimated Final Cost Mine Reclamation	58,000,000
Total Amount Collected through a Rider for Final Mine Closure and Reclamation Costs	64,000,000
Amount Collected through a Rider for Final Mine Closure - Other Liabilities Noncurrent	16,000,000
Amount Collected through a Rider for Final Mine Closure - ARO Noncurrent	48,000,000
Indiana Michigan Power Co [Member] | Letters of Credit [Member]
Maximum Future Payments for Letters of Credit [Abstract]
Maximum Future Payments for Letters of Credit	35,000
Pollution Control Bonds Supported by Bilateral Letters of Credit [Abstract]
Variable Rate PCBs Supported	77,000,000
Bilateral Letters of Credit	77,886,000
Commitments, Guarantees and Contingencies (Textuals) [Abstract]
Maximum Future Payments for Letters of Credit	35,000
Variable Rate PCBs Supported	77,000,000
Bilateral Letters of Credit	77,886,000
Indiana Michigan Power Co [Member] | Master Lease Agreements [Member]
Maximum Potential Loss on Master Lease Agreements [Abstract]
Max Potential Loss on Master Lease Agreements	2,914,000
Commitments, Guarantees and Contingencies (Textuals) [Abstract]
Max Potential Loss on Master Lease Agreements	2,914,000
Future Minimum Lease Obligation for Remaining Railcars	11,000,000
Guaranteed Sales Proceeds Percentage of Fair Value to Lessor Current Term	83.00%
Guaranteed Sales Proceeds Percentage of Fair Value to Lessor End of Max Lease Term	77.00%
Maximum Potential Loss on Guarantee of Return-and-Sale Option	9,000,000
Southwestern Electric Power Co [Member] | Master Lease Agreements [Member]
Maximum Potential Loss on Master Lease Agreements [Abstract]
Max Potential Loss on Master Lease Agreements	2,588,000
Commitments, Guarantees and Contingencies (Textuals) [Abstract]
Max Potential Loss on Master Lease Agreements	2,588,000
Future Minimum Lease Obligation for Remaining Railcars	13,000,000
Guaranteed Sales Proceeds Percentage of Fair Value to Lessor Current Term	83.00%
Guaranteed Sales Proceeds Percentage of Fair Value to Lessor End of Max Lease Term	77.00%
Maximum Potential Loss on Guarantee of Return-and-Sale Option	10,000,000
Southwestern Electric Power Co [Member] | Guarantees of Third Party Obligations [Member]
Commitments, Guarantees and Contingencies (Textuals) [Abstract]
Guarantees of Mine Reclamation, Amount	115,000,000
Estimated Final Cost Mine Reclamation	58,000,000
Total Amount Collected through a Rider for Final Mine Closure and Reclamation Costs	64,000,000
Amount Collected through a Rider for Final Mine Closure - Other Liabilities Noncurrent	16,000,000
Amount Collected through a Rider for Final Mine Closure - ARO Noncurrent	48,000,000
Ohio Power Co [Member] | Letters of Credit [Member]
Maximum Future Payments for Letters of Credit [Abstract]
Maximum Future Payments for Letters of Credit	4,200,000
Commitments, Guarantees and Contingencies (Textuals) [Abstract]
Maximum Future Payments for Letters of Credit	4,200,000
Ohio Power Co [Member] | Master Lease Agreements [Member]
Maximum Potential Loss on Master Lease Agreements [Abstract]
Max Potential Loss on Master Lease Agreements	4,886,000
Commitments, Guarantees and Contingencies (Textuals) [Abstract]
Max Potential Loss on Master Lease Agreements	4,886,000
Appalachian Power Co [Member] | Letters of Credit [Member]
Pollution Control Bonds Supported by Bilateral Letters of Credit [Abstract]
Variable Rate PCBs Supported	229,650,000
Bilateral Letters of Credit	232,293,000
Commitments, Guarantees and Contingencies (Textuals) [Abstract]
Variable Rate PCBs Supported	229,650,000
Bilateral Letters of Credit	232,293,000
Appalachian Power Co [Member] | Master Lease Agreements [Member]
Maximum Potential Loss on Master Lease Agreements [Abstract]
Max Potential Loss on Master Lease Agreements	4,053,000
Commitments, Guarantees and Contingencies (Textuals) [Abstract]
Max Potential Loss on Master Lease Agreements	4,053,000
Public Service Co Of Oklahoma [Member] | Master Lease Agreements [Member]
Maximum Potential Loss on Master Lease Agreements [Abstract]
Max Potential Loss on Master Lease Agreements	2,263,000
Commitments, Guarantees and Contingencies (Textuals) [Abstract]
Max Potential Loss on Master Lease Agreements	2,263,000
Superfund and State Remediation [Member]
Commitments, Guarantees and Contingencies (Textuals) [Abstract]
Expense Recorded Due to Remediation Work Remaining Provision	9,000,000
Superfund and State Remediation [Member] | Indiana Michigan Power Co [Member]
Commitments, Guarantees and Contingencies (Textuals) [Abstract]
Expense Recorded Due to Remediation Work Remaining Provision	$ 9,000,000