Sustainable Cost Reductions (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2012
Sustainable Cost Reductions [Abstract]
Incurred	$ 14,000
Settled	(12,000)
Remaining Balance	2,000
Appalachian Power Co [Member]
Sustainable Cost Reductions [Abstract]
Expense Allocation from AEPSC	2,076
Incurred	715
Settled	(2,780)
Remaining Balance	11
Indiana Michigan Power Co [Member]
Sustainable Cost Reductions [Abstract]
Expense Allocation from AEPSC	1,231
Incurred	277
Settled	(1,480)
Remaining Balance	28
Ohio Power Co [Member]
Sustainable Cost Reductions [Abstract]
Expense Allocation from AEPSC	3,099
Incurred	756
Settled	(3,827)
Remaining Balance	28
Public Service Co Of Oklahoma [Member]
Sustainable Cost Reductions [Abstract]
Expense Allocation from AEPSC	1,121
Incurred	3
Settled	(1,124)
Remaining Balance	0
Southwestern Electric Power Co [Member]
Sustainable Cost Reductions [Abstract]
Expense Allocation from AEPSC	1,367
Incurred	898
Settled	(2,241)
Remaining Balance	$ 24