Sustainable Cost Reductions (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2012
Sustainable Cost Reductions [Abstract]
Beginning Balance	$ 8,000
Incurred	13,000
Settled	(5,000)
Remaining Balance	8,000
Appalachian Power Co [Member]
Sustainable Cost Reductions [Abstract]
Beginning Balance	705
Expense Allocation from AEPSC	2,010
Incurred	730
Settled	(2,035)
Remaining Balance	705
Indiana Michigan Power Co [Member]
Sustainable Cost Reductions [Abstract]
Beginning Balance	187
Expense Allocation from AEPSC	1,204
Incurred	71
Settled	(1,088)
Remaining Balance	187
Ohio Power Co [Member]
Sustainable Cost Reductions [Abstract]
Beginning Balance	187
Expense Allocation from AEPSC	3,005
Incurred	442
Settled	(3,260)
Remaining Balance	187
Public Service Co Of Oklahoma [Member]
Sustainable Cost Reductions [Abstract]
Beginning Balance	0
Expense Allocation from AEPSC	1,080
Incurred	3
Settled	(1,083)
Remaining Balance	0
Southwestern Electric Power Co [Member]
Sustainable Cost Reductions [Abstract]
Beginning Balance	425
Expense Allocation from AEPSC	1,324
Incurred	533
Settled	(1,432)
Remaining Balance	$ 425