Short-Term Debt and Credit Facilities (Details) - USD ($) $ in Millions		9 Months Ended
		Sep. 30, 2016	Dec. 31, 2015
Line of Credit Facility [Line Items]
Short-term debt		$ 213.2	$ 0.0
Line of Credit Facility [Abstract]
Aggregate Commitment		1,150.0
Amount Outstanding	[1]	$ 214.9
Weighted Average Interest Rate		0.74%
Intercompany Borrowing Agreement, Expiration Date		Dec. 13, 2017
OGE Energy [Member]
Line of Credit Facility [Abstract]
Aggregate Commitment	[2]	$ 750.0
Amount Outstanding	[1],[2]	$ 213.2
Weighted Average Interest Rate	[2],[3]	0.74%
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]	$ 1.7
Weighted Average Interest Rate	[3],[5]	0.95%
Maturity	[4],[5]	Dec. 13, 2018
Short Term Borrowing Capacity That Has Regulatory Approval		$ 800.0
Period For Which Regulatory Approval Has Been Given to Acquire Short Term Debt		2 years
December 13, 2017 [Domain] | OGE Energy [Member]
Line of Credit Facility [Abstract]
Aggregate Commitment		$ 16.3
December 13, 2017 [Domain] | 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 September 30, 2016.

[2] 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.

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

[4] As of September 30, 2016, commitments of $16.3 million and $8.7 million of the OGE Energy's and OG&E's credit facilities, respectively, 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.