Consolidated Statements of Comprehensive Income (Loss) (Parenthetical) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Cash Flow Hedges, Tax	$ (20.9)	$ 0.5	$ (28.6)	$ 1.2
Amortization of Pension and OPEB Deferred Costs, Tax	0.3	0.3	0.7	0.7
Appalachian Power Co [Member]
Cash Flow Hedges, Tax	0.0	0.0	(0.1)	(0.1)
Amortization of Pension and OPEB Deferred Costs, Tax	0.1	0.2	0.3	0.4
AEP Texas Inc. [Member]
Cash Flow Hedges, Tax	0.0	0.0	0.1	0.1
Amortization of Pension and OPEB Deferred Costs, Tax	0.0	0.0	0.0	0.0
Indiana Michigan Power Co [Member]
Cash Flow Hedges, Tax	0.1	0.1	0.2	0.2
Amortization of Pension and OPEB Deferred Costs, Tax	0.0	0.0	0.0	0.0
Ohio Power Co [Member]
Cash Flow Hedges, Tax	(0.1)	(0.1)	(0.2)	(0.2)
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	0.1	0.1	0.2	0.2
Amortization of Pension and OPEB Deferred Costs, Tax	$ (0.1)	$ (0.1)	$ (0.2)	$ (0.2)