Rate Matters (Details) (USD $) In Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010	Dec. 31, 2010
Appalachian Power Co [Member]
Regulatory Assets Not Being Recovered [Abstract]
Regulatory Assets, Noncurrent	$ 1,506,936		$ 1,506,936		$ 1,486,625
Rate Matters (Textuals) [Abstract]
Regulatory Assets, Noncurrent	1,506,936		1,506,936		1,486,625
Regulatory Liabilities, Noncurrent	566,314		566,314		562,381
Subsidiary's Capitalized AFUDC and Interest Excluding Costs Attributable to Joint Owners	1,212	128	2,095	1,291
Construction in Progress, Gross	241,339		241,339		562,280
Southwestern Electric Power Co [Member]
Regulatory Assets Not Being Recovered [Abstract]
Regulatory Assets, Noncurrent	349,174		349,174		332,698
Rate Matters (Textuals) [Abstract]
Regulatory Assets, Noncurrent	349,174		349,174		332,698
Regulatory Liabilities, Noncurrent	417,571		417,571		393,673
Subsidiary's Capitalized AFUDC and Interest Excluding Costs Attributable to Joint Owners	11,573	12,462	22,169	27,979
Construction in Progress, Gross	1,268,429		1,268,429		1,071,603
Ohio Power Co [Member]
Regulatory Assets Not Being Recovered [Abstract]
Regulatory Assets, Noncurrent	1,004,684		1,004,684		934,011
Rate Matters (Textuals) [Abstract]
Regulatory Assets, Noncurrent	1,004,684		1,004,684		934,011
Regulatory Liabilities, Noncurrent	131,188		131,188		126,403
Subsidiary's Capitalized AFUDC and Interest Excluding Costs Attributable to Joint Owners	961	986	1,393	2,017
Construction in Progress, Gross	139,690		139,690		153,110
Columbus Southern Power Co [Member]
Regulatory Assets Not Being Recovered [Abstract]
Regulatory Assets, Noncurrent	313,651		313,651		298,111
Rate Matters (Textuals) [Abstract]
Regulatory Assets, Noncurrent	313,651		313,651		298,111
Regulatory Liabilities, Noncurrent	168,346		168,346		163,888
Subsidiary's Capitalized AFUDC and Interest Excluding Costs Attributable to Joint Owners	547	314	1,318	1,235
Construction in Progress, Gross	149,955		149,955		172,793
Public Service Co Of Oklahoma [Member]
Regulatory Assets Not Being Recovered [Abstract]
Regulatory Assets, Noncurrent	261,716		261,716		263,545
Rate Matters (Textuals) [Abstract]
Regulatory Assets, Noncurrent	261,716		261,716		263,545
Regulatory Liabilities, Noncurrent	329,669		329,669		336,961
Subsidiary's Capitalized AFUDC and Interest Excluding Costs Attributable to Joint Owners	284	119	650	366
Construction in Progress, Gross	43,372		43,372		59,091
Indiana Michigan Power Co [Member]
Regulatory Assets Not Being Recovered [Abstract]
Regulatory Assets, Noncurrent	519,181		519,181		556,254
Rate Matters (Textuals) [Abstract]
Regulatory Assets, Noncurrent	519,181		519,181		556,254
Regulatory Liabilities, Noncurrent	868,919		868,919		852,197
Subsidiary's Capitalized AFUDC and Interest Excluding Costs Attributable to Joint Owners			7,440	9,002
Construction in Progress, Gross	$ 338,627		$ 338,627		$ 301,534