Variable Interest Entities (Details) (USD $)	3 Months Ended			12 Months Ended
	Mar. 31, 2015		Mar. 31, 2014	Dec. 31, 2014
Variable Interest Entities (Textuals) [Abstract]
Securitization Bonds	2,227,000,000			$ 2,380,000,000
Securitized Transition Assets	2,001,000,000			2,072,000,000
AEP Credit, Inc. [Member]
Variable Interest Entities (Textuals) [Abstract]
Minimum Percentage of Equity AEP Provides	5.00%
Percentage of Short Term Borrowing Needs in Excess of Third Party Financings	20.00%
AEP Texas Central Transition Funding Co [Member]
Variable Interest Entities (Textuals) [Abstract]
Securitization Bonds	1,700,000,000			1,800,000,000
Securitized Transition Assets	1,600,000,000			1,600,000,000
Protected Cell Of Energy Insurance Services, Inc. [Member]
Variable Interest Entities (Textuals) [Abstract]
Insurance Premium Expense to Protected Cell	14,000,000		16,000,000
Transource Energy [Member]
Variable Interest Entities (Textuals) [Abstract]
Proceeds from Partnership Contribution	12,000,000			23,000,000
PATH West Virginia Transmission Co, LLC [Member]
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures [Abstract]
As Reported on the Consolidated Balance Sheet	21,000,000			21,000,000
Maximum Exposure	21,000,000			21,000,000
Advance Due to Parent [Member] | Dolet Hills Lignite Co, LLC [Member]
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures [Abstract]
As Reported on the Consolidated Balance Sheet	48,000,000			56,000,000
Maximum Exposure	48,000,000			56,000,000
Capital Contribution From Parent [Member] | PATH West Virginia Transmission Co, LLC [Member]
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures [Abstract]
As Reported on the Consolidated Balance Sheet	19,000,000			19,000,000
Maximum Exposure	19,000,000			19,000,000
Retained Earnings [Member] | PATH West Virginia Transmission Co, LLC [Member]
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures [Abstract]
As Reported on the Consolidated Balance Sheet	2,000,000			2,000,000
Maximum Exposure	2,000,000			2,000,000
SWEPCo's Guarantee Of Debt [Member] | Dolet Hills Lignite Co, LLC [Member]
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures [Abstract]
As Reported on the Consolidated Balance Sheet	0			0
Maximum Exposure	51,000,000			48,000,000
Current Assets [Member] | AEP Credit, Inc. [Member]
ASSETS
Assets	995,000,000			980,000,000
Current Assets [Member] | AEP Texas Central Transition Funding Co [Member]
ASSETS
Assets	169,000,000			239,000,000
Current Assets [Member] | Protected Cell Of Energy Insurance Services, Inc. [Member]
ASSETS
Assets	158,000,000			149,000,000
Current Assets [Member] | Transource Energy [Member]
ASSETS
Assets	16,000,000			2,000,000
Net Property Plant And Equipment [Member] | AEP Credit, Inc. [Member]
ASSETS
Assets	0			0
Net Property Plant And Equipment [Member] | AEP Texas Central Transition Funding Co [Member]
ASSETS
Assets	0			0
Net Property Plant And Equipment [Member] | Protected Cell Of Energy Insurance Services, Inc. [Member]
ASSETS
Assets	0			0
Net Property Plant And Equipment [Member] | Transource Energy [Member]
ASSETS
Assets	116,000,000			98,000,000
Other Non Current Assets [Member] | AEP Credit, Inc. [Member]
ASSETS
Assets	0			0
Other Non Current Assets [Member] | AEP Texas Central Transition Funding Co [Member]
ASSETS
Assets	1,594,000,000	[1]		1,654,000,000	[2]
Variable Interest Entities (Textuals) [Abstract]
Intercompany Item Eliminated in Consolidation	74,000,000			75,000,000
Other Non Current Assets [Member] | Protected Cell Of Energy Insurance Services, Inc. [Member]
ASSETS
Assets	2,000,000			2,000,000
Other Non Current Assets [Member] | Transource Energy [Member]
ASSETS
Assets	6,000,000			4,000,000
Total Assets [Member] | AEP Credit, Inc. [Member]
ASSETS
Assets	995,000,000			980,000,000
Total Assets [Member] | AEP Texas Central Transition Funding Co [Member]
ASSETS
Assets	1,763,000,000			1,893,000,000
Total Assets [Member] | Protected Cell Of Energy Insurance Services, Inc. [Member]
ASSETS
Assets	160,000,000			151,000,000
Total Assets [Member] | Transource Energy [Member]
ASSETS
Assets	138,000,000			104,000,000
Current Liabilities [Member] | AEP Credit, Inc. [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	895,000,000			894,000,000
Current Liabilities [Member] | AEP Texas Central Transition Funding Co [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	316,000,000			322,000,000
Current Liabilities [Member] | Protected Cell Of Energy Insurance Services, Inc. [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	50,000,000			44,000,000
Current Liabilities [Member] | Transource Energy [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	31,000,000			21,000,000
Noncurrent Liabilities [Member] | AEP Credit, Inc. [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	0			0
Noncurrent Liabilities [Member] | AEP Texas Central Transition Funding Co [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	1,429,000,000			1,553,000,000
Noncurrent Liabilities [Member] | Protected Cell Of Energy Insurance Services, Inc. [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	64,000,000			62,000,000
Noncurrent Liabilities [Member] | Transource Energy [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	60,000,000			55,000,000
Equity [Member] | AEP Credit, Inc. [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	100,000,000			86,000,000
Equity [Member] | AEP Texas Central Transition Funding Co [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	18,000,000			18,000,000
Equity [Member] | Protected Cell Of Energy Insurance Services, Inc. [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	46,000,000			45,000,000
Equity [Member] | Transource Energy [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	47,000,000			28,000,000
Total Liabilities And Equity [Member] | AEP Credit, Inc. [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	995,000,000			980,000,000
Total Liabilities And Equity [Member] | AEP Texas Central Transition Funding Co [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	1,763,000,000			1,893,000,000
Total Liabilities And Equity [Member] | Protected Cell Of Energy Insurance Services, Inc. [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	160,000,000			151,000,000
Total Liabilities And Equity [Member] | Transource Energy [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	138,000,000			104,000,000
Great Plains Energy Inc. [Member] | Transource Energy [Member]
Variable Interest Entities (Textuals) [Abstract]
Equity and Voting Ownership Percentage	13.50%
Transource Energy [Member]
Variable Interest Entities (Textuals) [Abstract]
Equity and Voting Ownership Percentage	86.50%
Appalachian Power Co [Member]
Related Party Transaction, Due from (to) Related Party, Current	152,148,000
Variable Interest Entities (Textuals) [Abstract]
Securitized Transition Assets	344,631,000			350,170,000
Appalachian Power Co [Member] | Appalachian Consumer Rate Relief Funding [Member]
Variable Interest Entities (Textuals) [Abstract]
Securitization Bonds	357,000,000			368,000,000
Securitized Transition Assets	345,000,000			350,000,000
Intercompany Item Eliminated in Consolidation	4,000,000			4,000,000
Appalachian Power Co [Member] | Billings from American Electric Power Service Corporation [Member]
Billings from Affiliates
Billings from VIE	48,248,000		50,136,000
Variable Interest Entities (Textuals) [Abstract]
Billings from VIE	48,248,000		50,136,000
Appalachian Power Co [Member] | Carrying Amount in AEPSC's Accounts Payable [Member]
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures [Abstract]
As Reported on the Consolidated Balance Sheet	16,935,000			30,692,000
Maximum Exposure	16,935,000			30,692,000
Appalachian Power Co [Member] | Current Assets [Member] | Appalachian Consumer Rate Relief Funding [Member]
ASSETS
Assets	10,886,000			18,099,000
Appalachian Power Co [Member] | Other Non Current Assets [Member] | Appalachian Consumer Rate Relief Funding [Member]
ASSETS
Assets	352,573,000	[3]		358,264,000	[3]
Appalachian Power Co [Member] | Total Assets [Member] | Appalachian Consumer Rate Relief Funding [Member]
ASSETS
Assets	363,459,000			376,363,000
Appalachian Power Co [Member] | Current Liabilities [Member] | Appalachian Consumer Rate Relief Funding [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	24,397,000			26,809,000
Appalachian Power Co [Member] | Noncurrent Liabilities [Member] | Appalachian Consumer Rate Relief Funding [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	337,336,000			347,652,000
Appalachian Power Co [Member] | Equity [Member] | Appalachian Consumer Rate Relief Funding [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	1,726,000			1,902,000
Appalachian Power Co [Member] | Total Liabilities And Equity [Member] | Appalachian Consumer Rate Relief Funding [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	363,459,000			376,363,000
Indiana Michigan Power Co [Member]
Related Party Transaction, Due from (to) Related Party, Current	(154,653,000)
Indiana Michigan Power Co [Member] | DCC Fuel [Member]
Variable Interest Entities (Textuals) [Abstract]
Payments Made by I&M to DCC Fuel	23,000,000		25,000,000
Indiana Michigan Power Co [Member] | Billings from AEP Generating Co [Member]
Billings from Affiliates
Billings from VIE	54,965,000		70,422,000
Variable Interest Entities (Textuals) [Abstract]
Billings from VIE	54,965,000		70,422,000
Indiana Michigan Power Co [Member] | Billings from American Electric Power Service Corporation [Member]
Billings from Affiliates
Billings from VIE	33,502,000		31,969,000
Variable Interest Entities (Textuals) [Abstract]
Billings from VIE	33,502,000		31,969,000
Indiana Michigan Power Co [Member] | Carrying Amount in AEPSC's Accounts Payable [Member]
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures [Abstract]
As Reported on the Consolidated Balance Sheet	12,795,000			22,480,000
Maximum Exposure	12,795,000			22,480,000
Indiana Michigan Power Co [Member] | Carrying Amount in AEGCo's Accounts Payable [Member]
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures [Abstract]
As Reported on the Consolidated Balance Sheet	14,982,000			20,031,000
Maximum Exposure	14,982,000			20,031,000
Indiana Michigan Power Co [Member] | Current Assets [Member] | DCC Fuel [Member]
ASSETS
Assets	89,509,000			97,361,000
Indiana Michigan Power Co [Member] | Net Property Plant And Equipment [Member] | DCC Fuel [Member]
ASSETS
Assets	128,919,000			158,121,000
Indiana Michigan Power Co [Member] | Other Non Current Assets [Member] | DCC Fuel [Member]
ASSETS
Assets	64,576,000			79,705,000
Indiana Michigan Power Co [Member] | Total Assets [Member] | DCC Fuel [Member]
ASSETS
Assets	283,004,000			335,187,000
Indiana Michigan Power Co [Member] | Current Liabilities [Member] | DCC Fuel [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	80,834,000			86,026,000
Indiana Michigan Power Co [Member] | Noncurrent Liabilities [Member] | DCC Fuel [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	202,170,000			249,161,000
Indiana Michigan Power Co [Member] | Total Liabilities And Equity [Member] | DCC Fuel [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	283,004,000			335,187,000
Public Service Co Of Oklahoma [Member]
Related Party Transaction, Due from (to) Related Party, Current	62,255,000
Public Service Co Of Oklahoma [Member] | Billings from American Electric Power Service Corporation [Member]
Billings from Affiliates
Billings from VIE	23,524,000		24,439,000
Variable Interest Entities (Textuals) [Abstract]
Billings from VIE	23,524,000		24,439,000
Public Service Co Of Oklahoma [Member] | Carrying Amount in AEPSC's Accounts Payable [Member]
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures [Abstract]
As Reported on the Consolidated Balance Sheet	8,005,000			15,338,000
Maximum Exposure	8,005,000			15,338,000
Southwestern Electric Power Co [Member]
Related Party Transaction, Due from (to) Related Party, Current	293,378,000
Southwestern Electric Power Co [Member] | Sabine Mining Co [Member]
Billings from Affiliates
Billings from VIE	42,000,000		39,000,000
Variable Interest Entities (Textuals) [Abstract]
Billings from VIE	42,000,000		39,000,000
Southwestern Electric Power Co [Member] | Dolet Hills Lignite Co, LLC [Member]
Related Party Transaction, Due from (to) Related Party, Current	48,000,000			56,000,000
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures [Abstract]
As Reported on the Consolidated Balance Sheet	12,058,000			11,462,000
Maximum Exposure	111,455,000			115,796,000
Billings from Affiliates
Billings from VIE	15,000,000		2,000,000
Variable Interest Entities (Textuals) [Abstract]
Billings from VIE	15,000,000		2,000,000
Percentage of VIE Sales of Lignite Produced	50.00%
Percentage of DHLCs Debt Guaranteed by Each SWEPCo and CLECO	50.00%
Percentage of Management Fee Received by SWEPCo from DHLC	100.00%
Southwestern Electric Power Co [Member] | Billings from American Electric Power Service Corporation [Member]
Billings from Affiliates
Billings from VIE	31,514,000		33,023,000
Variable Interest Entities (Textuals) [Abstract]
Billings from VIE	31,514,000		33,023,000
Southwestern Electric Power Co [Member] | Carrying Amount in AEPSC's Accounts Payable [Member]
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures [Abstract]
As Reported on the Consolidated Balance Sheet	10,778,000			20,772,000
Maximum Exposure	10,778,000			20,772,000
Southwestern Electric Power Co [Member] | Capital Contribution From Parent [Member] | Dolet Hills Lignite Co, LLC [Member]
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures [Abstract]
As Reported on the Consolidated Balance Sheet	7,643,000			7,643,000
Maximum Exposure	7,643,000			7,643,000
Southwestern Electric Power Co [Member] | Retained Earnings [Member] | Dolet Hills Lignite Co, LLC [Member]
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures [Abstract]
As Reported on the Consolidated Balance Sheet	4,415,000			3,819,000
Maximum Exposure	4,415,000			3,819,000
Southwestern Electric Power Co [Member] | SWEPCo's Guarantee Of Debt [Member] | Dolet Hills Lignite Co, LLC [Member]
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures [Abstract]
As Reported on the Consolidated Balance Sheet	0			0
Maximum Exposure	99,397,000	[4]		104,334,000	[4]
Southwestern Electric Power Co [Member] | Current Assets [Member] | Sabine Mining Co [Member]
ASSETS
Assets	58,946,000			67,981,000
Southwestern Electric Power Co [Member] | Net Property Plant And Equipment [Member] | Sabine Mining Co [Member]
ASSETS
Assets	143,910,000			145,491,000
Southwestern Electric Power Co [Member] | Other Non Current Assets [Member] | Sabine Mining Co [Member]
ASSETS
Assets	59,272,000			51,578,000
Southwestern Electric Power Co [Member] | Total Assets [Member] | Sabine Mining Co [Member]
ASSETS
Assets	262,128,000			265,050,000
Southwestern Electric Power Co [Member] | Current Liabilities [Member] | Sabine Mining Co [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	28,620,000			36,286,000
Southwestern Electric Power Co [Member] | Noncurrent Liabilities [Member] | Sabine Mining Co [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	233,122,000			228,349,000
Southwestern Electric Power Co [Member] | Equity [Member] | Sabine Mining Co [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	386,000			415,000
Southwestern Electric Power Co [Member] | Total Liabilities And Equity [Member] | Sabine Mining Co [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	262,128,000			265,050,000
AEP Generating Co [Member] | Rockport Generating Plant (Unit No. 1) [Member]
Variable Interest Entities (Textuals) [Abstract]
Jointly Owned Utility Plant, Proportionate Ownership Share	50.00%
AEP Generating Co [Member] | Rockport Generating Plant (Unit No. 2) [Member]
Variable Interest Entities (Textuals) [Abstract]
Percentage Interest in Rockport Plant Unit 2 Lease	50.00%
AEP Generating Co [Member] | Lawrenceburg Generating Station [Member]
Variable Interest Entities (Textuals) [Abstract]
Jointly Owned Utility Plant, Proportionate Ownership Share	100.00%
Cleco Power, LLC [Member]
Variable Interest Entities (Textuals) [Abstract]
Percentage of VIE Sales of Lignite Produced	50.00%
First Energy Corp [Member] | Allegheny Series [Member]
Variable Interest Entities (Textuals) [Abstract]
Percentage Ownership of "Allegheny Series" by a Nonaffiliated Company	100.00%
Ohio Power Co [Member]
Related Party Transaction, Due from (to) Related Party, Current	291,256,000
Variable Interest Entities (Textuals) [Abstract]
Securitized Transition Assets	103,924,000			109,999,000
Ohio Power Co [Member] | Billings from American Electric Power Service Corporation [Member]
Billings from Affiliates
Billings from VIE	39,230,000		39,049,000
Variable Interest Entities (Textuals) [Abstract]
Billings from VIE	39,230,000		39,049,000
Ohio Power Co [Member] | Carrying Amount in AEPSC's Accounts Payable [Member]
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures [Abstract]
As Reported on the Consolidated Balance Sheet	13,376,000			24,695,000
Maximum Exposure	13,376,000			24,695,000
Ohio Power Co [Member] | Ohio Phase-In-Recovery Funding [Member]
Variable Interest Entities (Textuals) [Abstract]
Securitization Bonds	210,000,000			232,000,000
Securitized Transition Assets	104,000,000			110,000,000
Ohio Power Co [Member] | Current Assets [Member] | Ohio Phase-In-Recovery Funding [Member]
ASSETS
Assets	21,606,000			32,676,000
Ohio Power Co [Member] | Other Non Current Assets [Member] | Ohio Phase-In-Recovery Funding [Member]
ASSETS
Assets	198,266,000	[5]		209,922,000	[5]
Variable Interest Entities (Textuals) [Abstract]
Intercompany Item Eliminated in Consolidation	92,000,000			97,000,000
Ohio Power Co [Member] | Total Assets [Member] | Ohio Phase-In-Recovery Funding [Member]
ASSETS
Assets	219,872,000			242,598,000
Ohio Power Co [Member] | Current Liabilities [Member] | Ohio Phase-In-Recovery Funding [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	46,756,000			47,099,000
Ohio Power Co [Member] | Noncurrent Liabilities [Member] | Ohio Phase-In-Recovery Funding [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	171,779,000			194,162,000
Ohio Power Co [Member] | Equity [Member] | Ohio Phase-In-Recovery Funding [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	1,337,000			1,337,000
Ohio Power Co [Member] | Total Liabilities And Equity [Member] | Ohio Phase-In-Recovery Funding [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	219,872,000			$ 242,598,000

[1] Includes an intercompany item eliminated in consolidation of $74 million

[2] Includes an intercompany item eliminated in consolidation of $75 million

[3] Includes an intercompany item eliminated in consolidation as of March 31, 2015 and December 31, 2014 of $4 million and $4 million, respectively.

[4] (a)Includes affiliate advances due to Parent related to participation in the Utility Money Pool of $48 million and $56 million in 2015 and 2014, respectively.

[5] Includes an intercompany item eliminated in consolidation as of March 31, 2015 and December 31, 2014 of $92 million and $97 million, respectively.