Rate Matters and Regulation (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Oklahoma Corporation Commission [Member]
OG&E's Jurisdictional Revenues	86.00%
Arkansas Public Service Commission [Member]
OG&E's Jurisdictional Revenues	8.00%
Federal Energy Regulatory Commission [Member]
OG&E's Jurisdictional Revenues	6.00%
Regional Haze [Member]
Estimated Environmental Capital Costs	$ 1,100.0
SmartHours Program [Member]
Lost Revenue Associated with Customer Programs	14.9	$ 11.6	$ 10.1
Oklahoma Public Utility Division Staff [Member] | SmartHours Program [Member]
Lost Revenue Associated with Customer Programs			4.9
Reduction of Revenue			$ 5.2
Environmental Compliance Plan [Member]
Public Utilities, Property, Plant and Equipment, Construction Work in Progress	94.8
Expected Construction Work in Progress Costs	35.0
OKLAHOMA
Public Utilities, Requested Rate Increase (Decrease), Amount	$ 92.5
Public Utilities, Requested Return on Equity, Percentage	10.25%
Investments Since Last Rate Case	$ 1,600.0