Variable Interest Entities (Details) (USD $)	3 Months Ended			6 Months Ended
	Jun. 30, 2013		Jun. 30, 2012	Jun. 30, 2013		Jun. 30, 2012	Dec. 31, 2012
Variable Interest Entities (Textuals) [Abstract]
Securitization Bonds	$ 2,150,000,000			$ 2,150,000,000			$ 2,281,000,000
Securitized Transition Assets	2,013,000,000			2,013,000,000			2,117,000,000
Percentage Ownership of "Allegheny Series" by a Nonaffiliated Company				100.00%
Sabine Mining Co [Member]
Billings from Affiliates
Billings from VIE	40,000,000		36,000,000	84,000,000		91,000,000
Variable Interest Entities (Textuals) [Abstract]
Billings from VIE	40,000,000		36,000,000	84,000,000		91,000,000
DCC Fuel [Member]
Variable Interest Entities (Textuals) [Abstract]
Payments Made by I&M to DCC Fuel	38,000,000		42,000,000	64,000,000		59,000,000
Protected Cell Of Energy Insurance Services, Inc. [Member]
Variable Interest Entities (Textuals) [Abstract]
Insurance Premium Expense to Protected Cell	14,000		0	15,000,000		15,000,000
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%
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	32,000,000			32,000,000			31,000,000
Maximum Exposure	32,000,000			32,000,000			31,000,000
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	9,000,000			9,000,000			9,000,000
Maximum Exposure	59,000,000			59,000,000			58,000,000
Billings from Affiliates
Billings from VIE	13,000,000		20,000,000	31,000,000		34,000,000
Variable Interest Entities (Textuals) [Abstract]
Billings from VIE	13,000,000		20,000,000	31,000,000		34,000,000
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%
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			19,000,000
Maximum Exposure	19,000,000			19,000,000			19,000,000
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	8,000,000			8,000,000			8,000,000
Maximum Exposure	8,000,000			8,000,000			8,000,000
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	13,000,000			13,000,000			12,000,000
Maximum Exposure	13,000,000			13,000,000			12,000,000
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	1,000,000			1,000,000			1,000,000
Maximum Exposure	1,000,000			1,000,000			1,000,000
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			0
Maximum Exposure	50,000,000			50,000,000			49,000,000
Current Assets [Member] | Sabine Mining Co [Member]
ASSETS
Assets	66,000,000			66,000,000			57,000,000
Current Assets [Member] | DCC Fuel [Member]
ASSETS
Assets	161,000,000			161,000,000			133,000,000
Current Assets [Member] | Protected Cell Of Energy Insurance Services, Inc. [Member]
ASSETS
Assets	136,000,000			136,000,000			130,000,000
Current Assets [Member] | AEP Credit, Inc. [Member]
ASSETS
Assets	963,000,000			963,000,000			843,000,000
Current Assets [Member] | AEP Texas Central Transition Funding Co [Member]
ASSETS
Assets	221,000,000			221,000,000			250,000,000
Net Property Plant And Equipment [Member] | Sabine Mining Co [Member]
ASSETS
Assets	163,000,000			163,000,000			170,000,000
Net Property Plant And Equipment [Member] | DCC Fuel [Member]
ASSETS
Assets	219,000,000			219,000,000			176,000,000
Net Property Plant And Equipment [Member] | Protected Cell Of Energy Insurance Services, Inc. [Member]
ASSETS
Assets	0			0			0
Net Property Plant And Equipment [Member] | AEP Credit, Inc. [Member]
ASSETS
Assets	0			0			0
Net Property Plant And Equipment [Member] | AEP Texas Central Transition Funding Co [Member]
ASSETS
Assets	0			0			0
Other Non Current Assets [Member] | Sabine Mining Co [Member]
ASSETS
Assets	66,000,000			66,000,000			55,000,000
Other Non Current Assets [Member] | DCC Fuel [Member]
ASSETS
Assets	104,000,000			104,000,000			92,000,000
Other Non Current Assets [Member] | Protected Cell Of Energy Insurance Services, Inc. [Member]
ASSETS
Assets	5,000,000			5,000,000			4,000,000
Other Non Current Assets [Member] | AEP Credit, Inc. [Member]
ASSETS
Assets	0			0			1,000,000
Other Non Current Assets [Member] | AEP Texas Central Transition Funding Co [Member]
ASSETS
Assets	2,060,000,000	[1]		2,060,000,000	[1]		2,167,000,000	[2]
Variable Interest Entities (Textuals) [Abstract]
Intercompany Item Eliminated in Consolidation	86,000,000			86,000,000			89,000,000
Total Assets [Member] | Sabine Mining Co [Member]
ASSETS
Assets	295,000,000			295,000,000			282,000,000
Total Assets [Member] | DCC Fuel [Member]
ASSETS
Assets	484,000,000			484,000,000			401,000,000
Total Assets [Member] | Protected Cell Of Energy Insurance Services, Inc. [Member]
ASSETS
Assets	141,000,000			141,000,000			134,000,000
Total Assets [Member] | AEP Credit, Inc. [Member]
ASSETS
Assets	963,000,000			963,000,000			844,000,000
Total Assets [Member] | AEP Texas Central Transition Funding Co [Member]
ASSETS
Assets	2,281,000,000			2,281,000,000			2,417,000,000
Current Liabilities [Member] | Sabine Mining Co [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	31,000,000			31,000,000			32,000,000
Current Liabilities [Member] | DCC Fuel [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	143,000,000			143,000,000			121,000,000
Current Liabilities [Member] | Protected Cell Of Energy Insurance Services, Inc. [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	42,000,000			42,000,000			43,000,000
Current Liabilities [Member] | AEP Credit, Inc. [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	904,000,000			904,000,000			800,000,000
Current Liabilities [Member] | AEP Texas Central Transition Funding Co [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	307,000,000			307,000,000			304,000,000
Noncurrent Liabilities [Member] | Sabine Mining Co [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	264,000,000			264,000,000			250,000,000
Noncurrent Liabilities [Member] | DCC Fuel [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	341,000,000			341,000,000			280,000,000
Noncurrent Liabilities [Member] | Protected Cell Of Energy Insurance Services, Inc. [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	68,000,000			68,000,000			66,000,000
Noncurrent Liabilities [Member] | AEP Credit, Inc. [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	1,000,000			1,000,000			1,000,000
Noncurrent Liabilities [Member] | AEP Texas Central Transition Funding Co [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	1,956,000,000			1,956,000,000			2,095,000,000
Equity [Member] | Sabine Mining Co [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	0			0			0
Equity [Member] | DCC Fuel [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	0			0			0
Equity [Member] | Protected Cell Of Energy Insurance Services, Inc. [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	31,000,000			31,000,000			25,000,000
Equity [Member] | AEP Credit, Inc. [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	58,000,000			58,000,000			43,000,000
Equity [Member] | AEP Texas Central Transition Funding Co [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	18,000,000			18,000,000			18,000,000
Total Liabilities And Equity [Member] | Sabine Mining Co [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	295,000,000			295,000,000			282,000,000
Total Liabilities And Equity [Member] | DCC Fuel [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	484,000,000			484,000,000			401,000,000
Total Liabilities And Equity [Member] | Protected Cell Of Energy Insurance Services, Inc. [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	141,000,000			141,000,000			134,000,000
Total Liabilities And Equity [Member] | AEP Credit, Inc. [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	963,000,000			963,000,000			844,000,000
Total Liabilities And Equity [Member] | AEP Texas Central Transition Funding Co [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	2,281,000,000			2,281,000,000			2,417,000,000
Appalachian Power Co [Member] | Billings from American Electric Power Service Corporation [Member]
Billings from Affiliates
Billings from VIE	41,496,000		43,894,000	80,537,000		82,440,000
Variable Interest Entities (Textuals) [Abstract]
Billings from VIE	41,496,000		43,894,000	80,537,000		82,440,000
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	12,440,000			12,440,000			29,819,000
Maximum Exposure	12,440,000			12,440,000			29,819,000
Indiana Michigan Power Co [Member] | DCC Fuel [Member]
Variable Interest Entities (Textuals) [Abstract]
Payments Made by I&M to DCC Fuel	38,000,000		42,000,000	64,000,000		59,000,000
Indiana Michigan Power Co [Member] | Billings from AEP Generating Co [Member]
Billings from Affiliates
Billings from VIE	53,191,000		53,917,000	111,726,000		112,739,000
Variable Interest Entities (Textuals) [Abstract]
Billings from VIE	53,191,000		53,917,000	111,726,000		112,739,000
Indiana Michigan Power Co [Member] | Billings from American Electric Power Service Corporation [Member]
Billings from Affiliates
Billings from VIE	28,706,000		31,377,000	56,204,000		57,484,000
Variable Interest Entities (Textuals) [Abstract]
Billings from VIE	28,706,000		31,377,000	56,204,000		57,484,000
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	7,764,000			7,764,000			17,911,000
Maximum Exposure	7,764,000			7,764,000			17,911,000
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	20,126,000			20,126,000			25,498,000
Maximum Exposure	20,126,000			20,126,000			25,498,000
Indiana Michigan Power Co [Member] | Current Assets [Member] | DCC Fuel [Member]
ASSETS
Assets	161,377,000			161,377,000			132,886,000
Indiana Michigan Power Co [Member] | Net Property Plant And Equipment [Member] | DCC Fuel [Member]
ASSETS
Assets	219,101,000			219,101,000			176,065,000
Indiana Michigan Power Co [Member] | Other Non Current Assets [Member] | DCC Fuel [Member]
ASSETS
Assets	104,035,000			104,035,000			92,473,000
Indiana Michigan Power Co [Member] | Total Assets [Member] | DCC Fuel [Member]
ASSETS
Assets	484,513,000			484,513,000			401,424,000
Indiana Michigan Power Co [Member] | Current Liabilities [Member] | DCC Fuel [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	142,829,000			142,829,000			120,873,000
Indiana Michigan Power Co [Member] | Noncurrent Liabilities [Member] | DCC Fuel [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	341,684,000			341,684,000			280,551,000
Indiana Michigan Power Co [Member] | Equity [Member] | DCC Fuel [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	0			0			0
Indiana Michigan Power Co [Member] | Total Liabilities And Equity [Member] | DCC Fuel [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	484,513,000			484,513,000			401,424,000
Ohio Power Co [Member] | Billings from AEP Generating Co [Member]
Billings from Affiliates
Billings from VIE	31,910,000		44,823,000	70,621,000		103,239,000
Variable Interest Entities (Textuals) [Abstract]
Billings from VIE	31,910,000		44,823,000	70,621,000		103,239,000
Ohio Power Co [Member] | Billings from American Electric Power Service Corporation [Member]
Billings from Affiliates
Billings from VIE	57,351,000		67,490,000	111,420,000		120,935,000
Variable Interest Entities (Textuals) [Abstract]
Billings from VIE	57,351,000		67,490,000	111,420,000		120,935,000
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	16,800,000			16,800,000			39,323,000
Maximum Exposure	16,800,000			16,800,000			39,323,000
Ohio 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	12,771,000			12,771,000			16,302,000
Maximum Exposure	12,771,000			12,771,000			16,302,000
Public Service Co Of Oklahoma [Member] | Billings from American Electric Power Service Corporation [Member]
Billings from Affiliates
Billings from VIE	19,807,000		21,301,000	37,969,000		38,897,000
Variable Interest Entities (Textuals) [Abstract]
Billings from VIE	19,807,000		21,301,000	37,969,000		38,897,000
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	5,380,000			5,380,000			13,381,000
Maximum Exposure	5,380,000			5,380,000			13,381,000
Southwestern Electric Power Co [Member] | Sabine Mining Co [Member]
Billings from Affiliates
Billings from VIE	40,000,000		36,000,000	84,000,000		91,000,000
Variable Interest Entities (Textuals) [Abstract]
Billings from VIE	40,000,000		36,000,000	84,000,000		91,000,000
Southwestern Electric Power Co [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	8,617,000			8,617,000			8,589,000
Maximum Exposure	58,217,000			58,217,000			58,153,000
Billings from Affiliates
Billings from VIE	13,000,000		20,000,000	31,000,000		34,000,000
Variable Interest Entities (Textuals) [Abstract]
Billings from VIE	13,000,000		20,000,000	31,000,000		34,000,000
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	29,595,000		33,246,000	57,075,000		59,966,000
Variable Interest Entities (Textuals) [Abstract]
Billings from VIE	29,595,000		33,246,000	57,075,000		59,966,000
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	8,801,000			8,801,000			19,669,000
Maximum Exposure	8,801,000			8,801,000			19,669,000
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			7,643,000
Maximum Exposure	7,643,000			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	974,000			974,000			946,000
Maximum Exposure	974,000			974,000			946,000
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			0
Maximum Exposure	49,600,000			49,600,000			49,564,000
Southwestern Electric Power Co [Member] | Current Assets [Member] | Sabine Mining Co [Member]
ASSETS
Assets	65,744,000			65,744,000			56,535,000
Southwestern Electric Power Co [Member] | Net Property Plant And Equipment [Member] | Sabine Mining Co [Member]
ASSETS
Assets	163,078,000			163,078,000			170,436,000
Southwestern Electric Power Co [Member] | Other Non Current Assets [Member] | Sabine Mining Co [Member]
ASSETS
Assets	65,952,000			65,952,000			55,076,000
Southwestern Electric Power Co [Member] | Total Assets [Member] | Sabine Mining Co [Member]
ASSETS
Assets	294,774,000			294,774,000			282,047,000
Southwestern Electric Power Co [Member] | Current Liabilities [Member] | Sabine Mining Co [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	30,854,000			30,854,000			31,446,000
Southwestern Electric Power Co [Member] | Noncurrent Liabilities [Member] | Sabine Mining Co [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	263,553,000			263,553,000			250,340,000
Southwestern Electric Power Co [Member] | Equity [Member] | Sabine Mining Co [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	367,000			367,000			261,000
Southwestern Electric Power Co [Member] | Total Liabilities And Equity [Member] | Sabine Mining Co [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	$ 294,774,000			$ 294,774,000			$ 282,047,000
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%			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%			50.00%
AEP Generating Co [Member] | Lawrenceburg Generating Station [Member]
Variable Interest Entities (Textuals) [Abstract]
Jointly Owned Utility Plant, Proportionate Ownership Share	100.00%			100.00%
Cleco Power, LLC [Member] | Dolet Hills Lignite Co, LLC [Member]
Variable Interest Entities (Textuals) [Abstract]
Percentage of VIE Sales of Lignite Produced				50.00%

[1] Includes an intercompany item eliminated in consolidation of $86 million.

[2] Includes an intercompany item eliminated in consolidation of $89 million.