Derivative Instruments and Hedging Activities, Income Statement Presentation Related to Derivative Instruments (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013
Enogex [Member] | Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount Recognized in Other Comprehensive Income	$ 0
Amount Reclassifed from Accumulated Other Comprehensive Income (Loss) into Income	0
Amount Recognized in Income	0
Enogex [Member] | Not Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount Recognized in Income	(0.3)
Enogex [Member] | Natural gas [Member] | Fixed Swaps/Futures [Member] | Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount Recognized in Other Comprehensive Income	0
Amount Reclassifed from Accumulated Other Comprehensive Income (Loss) into Income	0.2
Amount Recognized in Income	0
Enogex [Member] | Natural gas [Member] | Fixed Swaps/Futures [Member] | Not Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount Recognized in Income	(0.3)
OGE Energy Corp. [Member] | Interest Rate Swap [Member] | Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount Recognized in Other Comprehensive Income	0
Amount Reclassifed from Accumulated Other Comprehensive Income (Loss) into Income	(0.2)
Amount Recognized in Income	$ 0