Business Segments (Details) (USD $)	3 Months Ended			1 Months Ended		3 Months Ended			3 Months Ended			3 Months Ended			3 Months Ended			3 Months Ended						3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Dec. 31, 2011	Apr. 27, 2012 AEP [Member] Partnership [Member]	Apr. 27, 2012 Great Plains Energy [Member] Partnership [Member]	Mar. 31, 2012 Utility Operations [Member]	Mar. 31, 2011 Utility Operations [Member]	Dec. 31, 2011 Utility Operations [Member]	Mar. 31, 2012 Transmission Operations [Member]	Mar. 31, 2011 Transmission Operations [Member]	Dec. 31, 2011 Transmission Operations [Member]	Mar. 31, 2012 Nonutility Operations - AEP River Operations [Member]	Mar. 31, 2011 Nonutility Operations - AEP River Operations [Member]	Dec. 31, 2011 Nonutility Operations - AEP River Operations [Member]	Mar. 31, 2012 Nonutility Operations - Generation and Marketing [Member]	Mar. 31, 2011 Nonutility Operations - Generation and Marketing [Member]	Dec. 31, 2011 Nonutility Operations - Generation and Marketing [Member]	Mar. 31, 2012 All Other [Member]		Mar. 31, 2011 All Other [Member]		Dec. 31, 2011 All Other [Member]		Mar. 31, 2012 Reconciling Adjustments [Member]		Mar. 31, 2011 Reconciling Adjustments [Member]	Dec. 31, 2011 Reconciling Adjustments [Member]
Revenues from:
External Customers	$ 3,625,000,000	$ 3,730,000,000				$ 3,362,000,000	$ 3,497,000,000		$ 1,000,000	$ 0		$ 172,000,000	$ 167,000,000		$ 85,000,000	$ 62,000,000		$ 5,000,000	[1]	$ 4,000,000	[1]			$ 0		$ 0
Other Operating Segments	0	0				23,000,000	27,000,000		2,000,000	0		7,000,000	5,000,000		0	1,000,000		2,000,000	[1]	1,000,000	[1]			(34,000,000)		(34,000,000)
TOTAL REVENUES	3,625,000,000	3,730,000,000				3,385,000,000	3,524,000,000		3,000,000	0		179,000,000	172,000,000		85,000,000	63,000,000		7,000,000	[1]	5,000,000	[1]			(34,000,000)		(34,000,000)
NET INCOME (LOSS)	390,000,000	355,000,000				384,000,000	374,000,000		9,000,000	4,000,000		9,000,000	7,000,000		(1,000,000)	1,000,000		(11,000,000)	[1]	(31,000,000)	[1]			0		0
Balance Sheet Information
Total Property, Plant and Equipment	56,223,000,000		55,670,000,000			54,839,000,000		54,396,000,000	410,000,000		323,000,000	612,000,000		608,000,000	617,000,000		590,000,000	11,000,000	[1]			11,000,000	[1]	(266,000,000)	[2]		(258,000,000)	[2]
Accumulated Depreciation and Amortization	18,791,000,000		18,699,000,000			18,474,000,000		18,393,000,000	1,000,000		0	143,000,000		136,000,000	225,000,000		219,000,000	10,000,000	[1]			10,000,000	[1]	(62,000,000)	[2]		(59,000,000)	[2]
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	37,432,000,000		36,971,000,000			36,365,000,000		36,003,000,000	409,000,000		323,000,000	469,000,000		472,000,000	392,000,000		371,000,000	1,000,000	[1]			1,000,000	[1]	(204,000,000)	[2]		(199,000,000)	[2]
Total Assets	$ 52,902,000,000		$ 52,223,000,000			$ 50,581,000,000		$ 50,093,000,000	$ 727,000,000		$ 594,000,000	$ 657,000,000		$ 659,000,000	$ 1,012,000,000		$ 868,000,000	$ 16,397,000,000	[1]			$ 16,751,000,000	[1]	$ (16,472,000,000)	[2],[3]		$ (16,742,000,000)	[2],[3]
Business Segments (Textuals) [Abstract]
Percentage ownership interest of Transource Energy LLC				86.50%	13.50%

[1] All Other includes: Parent's guarantee revenue received from affiliates, investment income, interest income and interest expense and other nonallocated costs. Forward natural gas contracts that were not sold with our natural gas pipeline and storage operations in 2004 and 2005. These contracts were financial derivatives which settled and expired in the fourth quarter of 2011. Revenue sharing related to the Plaquemine Cogeneration Facility which ended in the fourth quarter of 2011.

[2] Includes eliminations due to an intercompany capital lease.

[3] Reconciling Adjustments for Total Assets primarily include the elimination of intercompany advances to affiliates and intercompany accounts receivable along with the elimination of AEP's investments in subsidiary companies.