Quarterly Financial Data (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended												12 Months Ended
	Dec. 31, 2013		Sep. 30, 2013		Jun. 30, 2013		Mar. 31, 2013		Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013		Dec. 31, 2012	Dec. 31, 2011
Operating revenues	$ 508.9		$ 723.2		$ 734.2		$ 901.4		$ 862.1	$ 1,113.4	$ 855.0	$ 840.7	$ 2,867.7		$ 3,671.2	$ 3,915.9
Operating income	73.3		260.9		143.9		75.4		97.3	304.0	177.3	98.3	553.5		676.9	646.7
Net income	57.6		215.2		93.0		28.0		43.5	192.4	101.6	47.5	393.8		385.0	363.6
Net income attributable to OGE Energy	$ 57.6		$ 215.2		$ 91.7		$ 23.1		$ 38.5	$ 185.5	$ 93.9	$ 37.1	$ 387.6		$ 355.0	$ 342.9
Basic earnings per average common share attributable to OGE Energy common shareholders	$ 0.29	[1]	$ 1.08	[1]	$ 0.46	[1]	$ 0.12	[1]	$ 0.19	$ 0.94	$ 0.48	$ 0.19	$ 1.96	[1]	$ 1.80	$ 1.75
Diluted earnings per average common share attributable to OGE Energy common shareholders	$ 0.29	[1]	$ 1.08	[1]	$ 0.46	[1]	$ 0.12	[1]	$ 0.19	$ 0.94	$ 0.47	$ 0.19	$ 1.94	[1]	$ 1.79	$ 1.73

[1] Due to the impact of dilution on the earnings per share calculation, quarterly earnings per share amounts may not add to the total.