Variable Interest Entities (Details) (USD $)	3 Months Ended
	Mar. 31, 2013		Mar. 31, 2012	Dec. 31, 2012
Variable Interest Entities (Textuals) [Abstract]
Minimum Percentage of Equity AEP Provides	5.00%
Securitization Bonds	$ 2,176,000,000			$ 2,281,000,000
Securitized Transition Assets	2,065,000,000			2,117,000,000
Percentage Ownership of "Allegheny Series" by a Nonaffiliated Company	100.00%
Intercompany Item Eliminated in Consolidation				89,000,000
DCC Fuel [Member]
Variable Interest Entities (Textuals) [Abstract]
Payments Made by I&M to DCC Fuel	26,000,000		17,000,000
Protected Cell Of Energy Insurance Services, Inc. [Member]
Variable Interest Entities (Textuals) [Abstract]
Insurance Premium Expense to Protected Cell	15,000,000		15,000,000
AEP Credit, Inc. [Member]
Variable Interest Entities (Textuals) [Abstract]
Percentage of Short Term Borrowing Needs in Excess of Third Party Financings	20.00%
Dolet Hills Lignite Co, LLC [Member]
Billings from Affiliates
Billings from VIE	18,000,000		14,000,000
Variable Interest Entities (Textuals) [Abstract]
Billings from VIE	18,000,000		14,000,000
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
Maximum Exposure	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
Maximum Exposure	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	12,000,000			12,000,000
Maximum Exposure	12,000,000			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
Maximum Exposure	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
Maximum Exposure	40,000,000			49,000,000
Total Investment [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	31,000,000			31,000,000
Maximum Exposure	31,000,000			31,000,000
Total Investment [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	9,000,000			9,000,000
Maximum Exposure	49,000,000			58,000,000
Current Assets [Member] | Sabine Mining Co [Member]
ASSETS
Assets	64,000,000			57,000,000
Current Assets [Member] | DCC Fuel [Member]
ASSETS
Assets	128,000,000			133,000,000
Current Assets [Member] | Protected Cell Of Energy Insurance Services, Inc. [Member]
ASSETS
Assets	144,000,000			130,000,000
Current Assets [Member] | AEP Credit, Inc. [Member]
ASSETS
Assets	871,000,000			843,000,000
Current Assets [Member] | AEP Texas Central Transition Funding Co [Member]
ASSETS
Assets	174,000,000			250,000,000
Net Property Plant And Equipment [Member] | Sabine Mining Co [Member]
ASSETS
Assets	167,000,000			170,000,000
Net Property Plant And Equipment [Member] | DCC Fuel [Member]
ASSETS
Assets	146,000,000			176,000,000
Net Property Plant And Equipment [Member] | Protected Cell Of Energy Insurance Services, Inc. [Member]
ASSETS
Assets	0			0
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
Other Non Current Assets [Member] | Sabine Mining Co [Member]
ASSETS
Assets	66,000,000			55,000,000
Other Non Current Assets [Member] | DCC Fuel [Member]
ASSETS
Assets	73,000,000			92,000,000
Other Non Current Assets [Member] | Protected Cell Of Energy Insurance Services, Inc. [Member]
ASSETS
Assets	5,000,000			4,000,000
Other Non Current Assets [Member] | AEP Credit, Inc. [Member]
ASSETS
Assets	1,000,000			1,000,000
Other Non Current Assets [Member] | AEP Texas Central Transition Funding Co [Member]
ASSETS
Assets	2,114,000,000	[1]		2,167,000,000	[1]
Variable Interest Entities (Textuals) [Abstract]
Intercompany Item Eliminated in Consolidation	87,000,000
Total Assets [Member] | Sabine Mining Co [Member]
ASSETS
Assets	297,000,000			282,000,000
Total Assets [Member] | DCC Fuel [Member]
ASSETS
Assets	347,000,000			401,000,000
Total Assets [Member] | Protected Cell Of Energy Insurance Services, Inc. [Member]
ASSETS
Assets	149,000,000			134,000,000
Total Assets [Member] | AEP Credit, Inc. [Member]
ASSETS
Assets	872,000,000			844,000,000
Total Assets [Member] | AEP Texas Central Transition Funding Co [Member]
ASSETS
Assets	2,288,000,000			2,417,000,000
Current Liabilities [Member] | Sabine Mining Co [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	31,000,000			32,000,000
Current Liabilities [Member] | DCC Fuel [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	112,000,000			121,000,000
Current Liabilities [Member] | Protected Cell Of Energy Insurance Services, Inc. [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	49,000,000			43,000,000
Current Liabilities [Member] | AEP Credit, Inc. [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	827,000,000			800,000,000
Current Liabilities [Member] | AEP Texas Central Transition Funding Co [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	293,000,000			304,000,000
Noncurrent Liabilities [Member] | Sabine Mining Co [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	266,000,000			250,000,000
Noncurrent Liabilities [Member] | DCC Fuel [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	235,000,000			280,000,000
Noncurrent Liabilities [Member] | Protected Cell Of Energy Insurance Services, Inc. [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	72,000,000			66,000,000
Noncurrent Liabilities [Member] | AEP Credit, Inc. [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	1,000,000			1,000,000
Noncurrent Liabilities [Member] | AEP Texas Central Transition Funding Co [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	1,977,000,000			2,095,000,000
Equity [Member] | Sabine Mining Co [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	0			0
Equity [Member] | DCC Fuel [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	0			0
Equity [Member] | Protected Cell Of Energy Insurance Services, Inc. [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	28,000,000			25,000,000
Equity [Member] | AEP Credit, Inc. [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	44,000,000			43,000,000
Equity [Member] | AEP Texas Central Transition Funding Co [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	18,000,000			18,000,000
Total Liabilities And Equity [Member] | Sabine Mining Co [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	297,000,000			282,000,000
Total Liabilities And Equity [Member] | DCC Fuel [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	347,000,000			401,000,000
Total Liabilities And Equity [Member] | Protected Cell Of Energy Insurance Services, Inc. [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	149,000,000			134,000,000
Total Liabilities And Equity [Member] | AEP Credit, Inc. [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	872,000,000			844,000,000
Total Liabilities And Equity [Member] | AEP Texas Central Transition Funding Co [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	2,288,000,000			2,417,000,000
Appalachian Power Co [Member] | Billings from American Electric Power Service Corporation [Member]
Billings from Affiliates
Billings from VIE	39,040,000		38,546,000
Variable Interest Entities (Textuals) [Abstract]
Billings from VIE	39,040,000		38,546,000
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	14,324,000			29,819,000
Maximum Exposure	14,324,000			29,819,000
Indiana Michigan Power Co [Member] | DCC Fuel [Member]
Variable Interest Entities (Textuals) [Abstract]
Payments Made by I&M to DCC Fuel	26,000,000		17,000,000
Indiana Michigan Power Co [Member] | Billings from AEP Generating Co [Member]
Billings from Affiliates
Billings from VIE	58,535,000		58,822,000
Variable Interest Entities (Textuals) [Abstract]
Billings from VIE	58,535,000		58,822,000
Indiana Michigan Power Co [Member] | Billings from American Electric Power Service Corporation [Member]
Billings from Affiliates
Billings from VIE	27,498,000		26,107,000
Variable Interest Entities (Textuals) [Abstract]
Billings from VIE	27,498,000		26,107,000
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	7,902,000			17,911,000
Maximum Exposure	7,902,000			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	18,543,000			25,498,000
Maximum Exposure	18,543,000			25,498,000
Indiana Michigan Power Co [Member] | Current Assets [Member] | DCC Fuel [Member]
ASSETS
Assets	128,450,000			132,886,000
Indiana Michigan Power Co [Member] | Net Property Plant And Equipment [Member] | DCC Fuel [Member]
ASSETS
Assets	146,271,000			176,065,000
Indiana Michigan Power Co [Member] | Other Non Current Assets [Member] | DCC Fuel [Member]
ASSETS
Assets	72,589,000			92,473,000
Indiana Michigan Power Co [Member] | Total Assets [Member] | DCC Fuel [Member]
ASSETS
Assets	347,310,000			401,424,000
Indiana Michigan Power Co [Member] | Current Liabilities [Member] | DCC Fuel [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	112,209,000			120,873,000
Indiana Michigan Power Co [Member] | Noncurrent Liabilities [Member] | DCC Fuel [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	235,101,000			280,551,000
Indiana Michigan Power Co [Member] | Equity [Member] | DCC Fuel [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	0			0
Indiana Michigan Power Co [Member] | Total Liabilities And Equity [Member] | DCC Fuel [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	347,310,000			401,424,000
Ohio Power Co [Member] | Billings from AEP Generating Co [Member]
Billings from Affiliates
Billings from VIE	38,711,000		58,417,000
Variable Interest Entities (Textuals) [Abstract]
Billings from VIE	38,711,000		58,417,000
Ohio Power Co [Member] | Billings from American Electric Power Service Corporation [Member]
Billings from Affiliates
Billings from VIE	54,069,000		53,445,000
Variable Interest Entities (Textuals) [Abstract]
Billings from VIE	54,069,000		53,445,000
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	20,051,000			39,323,000
Maximum Exposure	20,051,000			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	12,889,000			16,302,000
Maximum Exposure	12,889,000			16,302,000
Public Service Co Of Oklahoma [Member] | Billings from American Electric Power Service Corporation [Member]
Billings from Affiliates
Billings from VIE	18,161,000		17,596,000
Variable Interest Entities (Textuals) [Abstract]
Billings from VIE	18,161,000		17,596,000
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	6,772,000			13,381,000
Maximum Exposure	6,772,000			13,381,000
Southwestern Electric Power Co [Member] | Sabine Mining Co [Member]
Billings from Affiliates
Billings from VIE	44,000,000		55,000,000
Variable Interest Entities (Textuals) [Abstract]
Billings from VIE	44,000,000		55,000,000
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	8,555,000			8,589,000
Maximum Exposure	48,523,000			58,153,000
Billings from Affiliates
Billings from VIE	18,000,000		14,000,000
Variable Interest Entities (Textuals) [Abstract]
Billings from VIE	18,000,000		14,000,000
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	27,480,000		26,720,000
Variable Interest Entities (Textuals) [Abstract]
Billings from VIE	27,480,000		26,720,000
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	9,048,000			19,669,000
Maximum Exposure	9,048,000			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
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	912,000			946,000
Maximum Exposure	912,000			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
Maximum Exposure	39,968,000			49,564,000
Southwestern Electric Power Co [Member] | Current Assets [Member] | Sabine Mining Co [Member]
ASSETS
Assets	64,194,000			56,535,000
Southwestern Electric Power Co [Member] | Net Property Plant And Equipment [Member] | Sabine Mining Co [Member]
ASSETS
Assets	167,256,000			170,436,000
Southwestern Electric Power Co [Member] | Other Non Current Assets [Member] | Sabine Mining Co [Member]
ASSETS
Assets	65,847,000			55,076,000
Southwestern Electric Power Co [Member] | Total Assets [Member] | Sabine Mining Co [Member]
ASSETS
Assets	297,297,000			282,047,000
Southwestern Electric Power Co [Member] | Current Liabilities [Member] | Sabine Mining Co [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	30,681,000			31,446,000
Southwestern Electric Power Co [Member] | Noncurrent Liabilities [Member] | Sabine Mining Co [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	266,229,000			250,340,000
Southwestern Electric Power Co [Member] | Equity [Member] | Sabine Mining Co [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	387,000			261,000
Southwestern Electric Power Co [Member] | Total Liabilities And Equity [Member] | Sabine Mining Co [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	$ 297,297,000			$ 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%
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] | Dolet Hills Lignite Co, LLC [Member]
Variable Interest Entities (Textuals) [Abstract]
Percentage of VIE Sales of Lignite Produced	50.00%

[1] Weighted average rate.