Consolidated Statements of Comprehensive Income (Loss) (Parenthetical) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Cash Flow Hedges, Tax	$ 8.2	$ 0.5	$ 4.2	$ (2.9)
Securities Available for Sale, Tax	0.4	(0.1)	0.7	0.2
Amortization of Pension and OPEB Deferred Costs, Tax	0.0	0.1	0.1	0.3
Appalachian Power Co [Member]
Cash Flow Hedges, Tax	(0.1)	0.0	(0.2)	0.1
Amortization of Pension and OPEB Deferred Costs, Tax	(0.2)	(0.3)	(0.4)	(0.5)
Indiana Michigan Power Co [Member]
Cash Flow Hedges, Tax	0.2	0.1	0.4	0.3
Ohio Power Co [Member]
Cash Flow Hedges, Tax	(0.2)	(0.2)	(0.4)	(0.4)
Public Service Co Of Oklahoma [Member]
Cash Flow Hedges, Tax	(0.1)	(0.1)	(0.2)	(0.2)
Southwestern Electric Power Co [Member]
Cash Flow Hedges, Tax	0.3	0.3	0.5	0.6
Amortization of Pension and OPEB Deferred Costs, Tax	$ (0.1)	$ (0.2)	$ (0.2)	$ (0.3)