Short-Term Debt and Credit Facilities (Details) - USD ($) $ in Millions		9 Months Ended
		Sep. 30, 2017	Dec. 31, 2016
Line of Credit Facility [Line Items]
Short-term debt		$ 146.5	$ 236.2
Line of Credit Facility [Abstract]
Aggregate Commitment		900.0
Long-term Line of Credit	[1]	$ 146.8
Weighted Average Interest Rate		1.43%
Maturity		Mar. 08, 2022
Ratio of Consolidated Debt to Consolidated Capitalization		65.00%
OGE Energy [Member]
Line of Credit Facility [Abstract]
Long-term Line of Credit	[1],[2]	$ 146.5
Weighted Average Interest Rate	[2],[3]	1.43%
Maturity	[2]	Mar. 08, 2022
OGE Energy [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Current Borrowing Capacity	[2]	$ 450.0
OG&E [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Current Borrowing Capacity	[4]	450.0
Line of Credit Facility [Abstract]
Aggregate Commitment		600.0
Letters of Credit Outstanding, Amount	[1],[4]	$ 0.3
Weighted Average Interest Rate	[3],[4]	0.95%
Maturity	[4]	Mar. 08, 2022
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
Debt Restriction Maximum Letters of Credit		$ 100.0
Available Optional Increase of Borrowing Capacity in Credit Facility		150.0
Acceleration of Debt [Member] | OG&E [Member]
Line of Credit Facility [Abstract]
Acceleration of Indebtedness of Credit Facility		100.0
Uninsured Judgements [Member] | OGE Energy [Member]
Line of Credit Facility [Abstract]
Acceleration of Indebtedness of Credit Facility		100.0
Uninsured Judgements [Member] | OG&E [Member]
Line of Credit Facility [Abstract]
Acceleration of Indebtedness of Credit Facility		$ 100.0

[1] Includes direct borrowings under the revolving credit agreements, commercial paper borrowings and letters of credit at September 30, 2017.

[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] 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.