Significant Accounting Matters (Details) (USD $)	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Dec. 31, 2011
Components of Accumulated Other Comprehensive Income (Loss) (AOCI)
Accumulated Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax	$ 4,000,000		$ 2,000,000
Basic and Diluted EPS Calculations
Earning Attributable to Common Stockholders	389,000,000	353,000,000
Weighted Average Number of Basic Shares Outstanding	483,828,101	481,144,270
Total Basic Earnings Per Share Attributable to AEP Common Shareholders	$ 0.80	$ 0.73
Weighted Average Dilutive Effect of:
Weighted Average Number of Diluted AEP Common Shares Outstanding	484,248,868	481,365,806
Total Diluted Earnings Per Share Attributable to AEP Common Shareholders	$ 0.80	$ 0.73
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	0	136,250
Amounts Attributable To AEP Common Shareholders
Net Income	389,000,000	353,000,000
Noncash Investing and Financing Activities:
Noncash Assumption of Liabilities Related to Acquisitions of Assets	56,000,000	0
Organization and Summary of Significant Accounting Policies (Textuals) [Abstract]
Minimum Percentage of Equity AEP Provides	5.00%
Percentage of DHLCs Debt Guaranteed by Each SWEPCo and CLECO	50.00%
Percentage of Management Fee Received by SWEPCo from DHLC	100.00%
Securitization Bonds	2,389,000,000		1,688,000,000
Securitized Transition Assets	2,289,000,000		1,627,000,000
Percentage Ownership of "Allegheny Series" by AYE	100.00%
Outstanding options to purchase of common stock, shares	0	136,250
DCC Fuel [Member]
Organization and Summary of Significant Accounting Policies (Textuals) [Abstract]
Payments made by I&M to DCC Fuel	17,000,000	6,000,000
Protected Cell Of Energy Insurance Services, Inc. [Member]
Organization and Summary of Significant Accounting Policies (Textuals) [Abstract]
Insurance Premium Expense to Protected Cell	15,000,000	30,000,000
AEP Credit, Inc. [Member]
Organization and Summary of Significant Accounting Policies (Textuals) [Abstract]
Percentage Of Short Term Borrowing Needs In Excess Of Third Party Financings	20.00%
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
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	11,000,000		10,000,000
Maximum Exposure	11,000,000		10,000,000
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	30,000,000		29,000,000
Maximum Exposure	30,000,000		29,000,000
Ohio Power Co [Member]
Basic and Diluted EPS Calculations
Earning Attributable to Common Stockholders	150,830,000	165,762,000
Amounts Attributable To AEP Common Shareholders
Net Income	150,830,000	165,762,000
Cleco Power, LLC [Member] | Dolet Hills Lignite Co, LLC [Member]
Organization and Summary of Significant Accounting Policies (Textuals) [Abstract]
Percentage of VIE Sales of Lignite Produced	50.00%
Southwestern Electric Power Co [Member]
Basic and Diluted EPS Calculations
Earning Attributable to Common Stockholders	35,312,000	28,688,000
Amounts Attributable To AEP Common Shareholders
Net Income	35,312,000	28,688,000
Southwestern Electric Power Co [Member] | Sabine Mining Co [Member]
Organization and Summary of Significant Accounting Policies (Textuals) [Abstract]
SWEPCo's Total Billings from Sabine or DHLC	55,000,000	33,000,000
Southwestern Electric Power Co [Member] | Dolet Hills Lignite Co, LLC [Member]
Organization and Summary of Significant Accounting Policies (Textuals) [Abstract]
SWEPCo's Total Billings from Sabine or DHLC	14,000,000	13,000,000
Percentage of VIE Sales of Lignite Produced	50.00%
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	8,000,000		8,000,000
Maximum Exposure	8,000,000		8,000,000
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	1,000,000		1,000,000
Maximum Exposure	1,000,000		1,000,000
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	54,000,000		52,000,000
Southwestern Electric Power Co [Member] | 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	63,000,000		61,000,000
Indiana Michigan Power Co [Member]
Basic and Diluted EPS Calculations
Earning Attributable to Common Stockholders	39,221,000	45,342,000
Amounts Attributable To AEP Common Shareholders
Net Income	39,221,000	45,342,000
Current Liabilities [Member] | Protected Cell Of Energy Insurance Services, Inc. [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	51,000,000		40,000,000
Current Liabilities [Member] | AEP Credit, Inc. [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	840,000,000		864,000,000
Current Liabilities [Member] | AEP Texas Central Transition Funding Co [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	248,000,000		229,000,000
Current Liabilities [Member] | Southwestern Electric Power Co [Member] | Sabine Mining Co [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	48,000,000		68,000,000
Current Liabilities [Member] | Indiana Michigan Power Co [Member] | DCC Fuel [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	92,000,000		103,000,000
Noncurrent Liabilities [Member] | Protected Cell Of Energy Insurance Services, Inc. [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	67,000,000		71,000,000
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	2,218,000,000		1,557,000,000
Noncurrent Liabilities [Member] | Southwestern Electric Power Co [Member] | Sabine Mining Co [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	251,000,000		176,000,000
Noncurrent Liabilities [Member] | Indiana Michigan Power Co [Member] | DCC Fuel [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	288,000,000		321,000,000
Equity [Member] | Protected Cell Of Energy Insurance Services, Inc. [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	18,000,000		16,000,000
Equity [Member] | AEP Credit, Inc. [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	45,000,000		46,000,000
Equity [Member] | AEP Texas Central Transition Funding Co [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	18,000,000		14,000,000
Equity [Member] | Southwestern Electric Power Co [Member] | Sabine Mining Co [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	0		0
Equity [Member] | Indiana Michigan Power Co [Member] | DCC Fuel [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	0		0
Total Liabilities And Equity [Member] | Protected Cell Of Energy Insurance Services, Inc. [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	136,000,000		127,000,000
Total Liabilities And Equity [Member] | AEP Credit, Inc. [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	886,000,000		911,000,000
Total Liabilities And Equity [Member] | AEP Texas Central Transition Funding Co [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	2,484,000,000		1,800,000,000
Total Liabilities And Equity [Member] | Southwestern Electric Power Co [Member] | Sabine Mining Co [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	299,000,000		244,000,000
Total Liabilities And Equity [Member] | Indiana Michigan Power Co [Member] | DCC Fuel [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	380,000,000		424,000,000
Current Assets [Member] | Protected Cell Of Energy Insurance Services, Inc. [Member]
ASSETS
Assets	130,000,000		121,000,000
Current Assets [Member] | AEP Credit, Inc. [Member]
ASSETS
Assets	885,000,000		910,000,000
Current Assets [Member] | AEP Texas Central Transition Funding Co [Member]
ASSETS
Assets	141,000,000		220,000,000
Current Assets [Member] | Southwestern Electric Power Co [Member] | Sabine Mining Co [Member]
ASSETS
Assets	75,000,000		48,000,000
Current Assets [Member] | Indiana Michigan Power Co [Member] | DCC Fuel [Member]
ASSETS
Assets	123,000,000		118,000,000
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
Net Property Plant And Equipment [Member] | Southwestern Electric Power Co [Member] | Sabine Mining Co [Member]
ASSETS
Assets	167,000,000		154,000,000
Net Property Plant And Equipment [Member] | Indiana Michigan Power Co [Member] | DCC Fuel [Member]
ASSETS
Assets	159,000,000		188,000,000
Other Non Current Assets [Member] | Protected Cell Of Energy Insurance Services, Inc. [Member]
ASSETS
Assets	6,000,000		6,000,000
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	2,343,000,000		1,580,000,000
Other Non Current Assets [Member] | Southwestern Electric Power Co [Member] | Sabine Mining Co [Member]
ASSETS
Assets	57,000,000		42,000,000
Other Non Current Assets [Member] | Indiana Michigan Power Co [Member] | DCC Fuel [Member]
ASSETS
Assets	98,000,000		118,000,000
Total Assets [Member] | Protected Cell Of Energy Insurance Services, Inc. [Member]
ASSETS
Assets	136,000,000		127,000,000
Total Assets [Member] | AEP Credit, Inc. [Member]
ASSETS
Assets	886,000,000		911,000,000
Total Assets [Member] | AEP Texas Central Transition Funding Co [Member]
ASSETS
Assets	2,484,000,000		1,800,000,000
Total Assets [Member] | Southwestern Electric Power Co [Member] | Sabine Mining Co [Member]
ASSETS
Assets	299,000,000		244,000,000
Total Assets [Member] | Indiana Michigan Power Co [Member] | DCC Fuel [Member]
ASSETS
Assets	380,000,000		424,000,000
Performance Share Units [Member]
Weighted Average Dilutive Effect of:
Weighted Average Dilutive Effect of Shares	0	0
Dilutive Effect, EPS	0	0
Stock Options [Member]
Weighted Average Dilutive Effect of:
Weighted Average Dilutive Effect of Shares	0	100,000
Dilutive Effect, EPS	0	0
Restricted Stock Units [Member]
Weighted Average Dilutive Effect of:
Weighted Average Dilutive Effect of Shares	400,000	200,000
Dilutive Effect, EPS	$ 0	$ 0