Short-Term Debt and Credit Facilities (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014
Line of Credit Facility [Line Items]
Short-term debt		$ 0.0	$ 98.0
Line of Credit Facility [Abstract]
Aggregate Commitment		1,150.0
Amount Outstanding	[1]	$ 1.9
Weighted Average Interest Rate		0.95%
OGE Energy [Member]
Line of Credit Facility [Abstract]
Weighted Average Interest Rate			0.41%
OGE Energy [Member]
Line of Credit Facility [Abstract]
Aggregate Commitment	[2]	$ 750.0
Amount Outstanding	[1],[2]	$ 0.0
Weighted Average Interest Rate	[2],[3]	0.00%
Maturity	[2],[4]	Dec. 13, 2018
OG&E [Member]
Line of Credit Facility [Abstract]
Aggregate Commitment	[5]	$ 400.0
Letters of Credit Outstanding, Amount	[1],[5]	$ 1.9
Weighted Average Interest Rate	[3],[5]	0.95%
Maturity	[4],[5]	Dec. 13, 2018
Period For Which Regulatory Approval Has Been Given to Acquire Short Term Debt		2 years
Short Term Borrowing Capacity That Has Regulatory Approval		$ 800.0
December 13, 2017 [Member] | OGE Energy [Member]
Line of Credit Facility [Abstract]
Aggregate Commitment		16.3
December 13, 2017 [Member] | OG&E [Member]
Line of Credit Facility [Abstract]
Aggregate Commitment		$ 8.7

[1] Includes direct borrowings under the revolving credit agreements, commercial paper borrowings and letters of credit at December 31, 2015.

[2] This bank facility is available to back up the Company's commercial paper borrowings and to provide revolving credit borrowings. This bank facility can also be used as a letter of credit facility.

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

[4] In December 2011, the Company and OG&E entered into unsecured five-year revolving credit agreements to total in the aggregate $1,150.0 million ($750.0 million for the Company and $400.0 million for OG&E). Each of the credit facilities contained an option, which could be exercised up to two times, to extend the term for an additional year. In the third quarter of 2013, the Company and OG&E utilized one of these one-year extensions, and received consent from all of the lenders, to extend the maturity of their credit agreements from December 13, 2016 to December 13, 2017. In the second quarter of 2014, the Company and OG&E utilized their second extension to extend the maturity of their respective credit facility from December 13, 2017 to December 13, 2018. As of December 31, 2015, commitments of approximately $16.3 million and $8.7 million of the Company's and OG&E's credit facilities, respectively, however, were not extended and, unless the non-extending lender is replaced in accordance with the terms of the credit facility, such commitments will expire December 13, 2017.

[5] 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.