Short-Term Debt and Credit Facilities (Details) (USD $) In Millions, unless otherwise specified						3 Months Ended
	Mar. 31, 2013		Dec. 31, 2012	Mar. 31, 2012	Dec. 31, 2011	Mar. 31, 2013 OGE Energy [Member]		Mar. 31, 2013 OG&E [Member]		May 01, 2013 Midstream Partnership [Member]	Mar. 31, 2013 Enogex Llc [Member]
Line of Credit Facility [Line Items]
Short-term debt	$ 707.0		$ 430.9
Line of Credit Facility [Abstract]
Aggregate Commitment	1,550.0					750.0	[1]	400.0		1,400.0	400.0	[2]
Amount Outstanding	709.1	[3]				663.9	[1],[3]	45.2	[3],[4]		0	[2],[3]
Cash	7.1		1.8	1.6	4.6
Total	1,557.1
Weighted Average Interest Rate	0.38%					0.38%	[1],[5]	0.33%	[4],[5]		0.00%	[2],[5]
Maturity						Dec. 13, 2016		Dec. 13, 2016
Letters of Credit Outstanding, Amount								2.1
Commercial Paper								43.1
Short Term Borrowing Capacity That Has Regulatory Approval								$ 800
Period For Which Regulatory Approval Has Been Given to Acquire Short Term Debt								2 years

[1] This bank facility is available to back up OGE Energy's commercial paper borrowings and to provide revolving credit borrowings. This bank facility can also be used as a letter of credit facility. At March 31, 2013, there was $663.9 million in outstanding commercial paper borrowings.

[2] This bank facility was available to provide revolving credit borrowings for Enogex LLC. Effective May 1, 2013, the Midstream Partnership entered into a $1.4 billion, five-year senior unsecured revolving credit facility in accordance with the terms of the Master Formation Agreement and Enogex LLC's $400 million revolving credit facility was terminated.

[3] Includes direct borrowings under the revolving credit agreements, commercial paper borrowings and letters of credit at March 31, 2013.

[4] This bank facility is available to back up OG&E's commercial paper borrowings and to provide revolving credit borrowings. This bank facility can also be used as a letter of credit facility. At March 31, 2013, there was $43.1 million in outstanding commercial paper borrowings and $2.1 million in letters of credit.

[5] Represents the weighted-average interest rate for the outstanding borrowings under the revolving credit agreements, commercial paper borrowings and letters of credit.