Investment in Unconsolidated Affiliate (Details) - USD ($) $ / shares in Units, $ in Millions		11 Months Ended		12 Months Ended
		Dec. 02, 2021		Dec. 31, 2021	Dec. 31, 2020		Dec. 31, 2019		Jun. 30, 2021	May 01, 2013
Schedule of Equity Method Investments [Line Items]
Limited Liability Company or Limited Partnership, Members or Limited Partners, Ownership Interest		25.50%			25.50%		25.50%
Distribution Made to Limited Partner, Distributions Declared, Per Unit				$ 0.175
Equity in earnings (losses) of unconsolidated affiliates		$ 169.8	[1]	$ 169.8	$ (668.0)	[1],[2]	$ 113.9	[1]
Share Price									$ 33.65
Investment Owned, Balance, Shares		110,982,805		95,389,721
Equity Method Investment, Other than Temporary Impairment	[3]	$ 0.0			(780.0)		0.0
Gain (Loss) on Disposition of Assets				$ 344.4	0.0		0.0
Proceeds from Sales of Assets, Investing Activities				35.0
fees paid from disposition of assets				8.6
Enable Midstream Partners [Member]
Schedule of Equity Method Investments [Line Items]
Distributions received				$ 73.4	91.7		144.0
Enogex LLC [Member]
Schedule of Equity Method Investments [Line Items]
Increase in fair value of net assets										$ 2,200.0
OGE Holdings [Member]
Schedule of Equity Method Investments [Line Items]
Limited Liability Company or Limited Partnership, Members or Limited Partners, Ownership Interest				25.50%
CenterPoint [Member]
Schedule of Equity Method Investments [Line Items]
Proceeds from Sales of Assets, Investing Activities				$ 30.0
Energy Transfer
Schedule of Equity Method Investments [Line Items]
Proceeds from Sales of Assets, Investing Activities				5.0
Natural Gas Midstream Operations [Member]
Schedule of Equity Method Investments [Line Items]
Equity in earnings (losses) of unconsolidated affiliates				169.8	$ (668.0)	[2]	$ 113.9
Gain (Loss) on Disposition of Assets				$ 344.4

[1] For the year ended December 31, 2020, Enable recorded a $225.0 million impairment on its SESH equity method investment. Enable estimated the fair value of this equity method investment was below the carrying value at September 30, 2020 and concluded the decline in value was other than temporary due to the expiration of a transportation contract and the current status of renewal negotiations. The impairment ran through OGE Energy's portion of Enable net income and was offset by basis differences that flow through the amortization of basis difference and dilution recognition line item above

[2] In March 2020, OGE Energy recorded a $780.0 million impairment on its investment in Enable, as further discussed in Notes 5 and 7.

[3] Effective March 31, 2020, OGE Energy estimated the fair value of its investment in Enable was below the book value and concluded the decline in value was not temporary due to the severity of the decline and recent rapid deterioration, as well as the near term future outlook, of the midstream oil and gas industry. Accordingly, OGE Energy recorded a $780.0 million impairment on its investment in Enable in 2020. Further information concerning the fair value method used to measure the impairment on OGE Energy's investment in Enable can be found in Note 7.