Summary of Significant Accounting Policies Property - Summary of Property Plant and Equipment (Parenthetical) (Details) - OG&E [Member] - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Electric Generation Equipment [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Amount of Acquisition Adjustments	$ 148.3	$ 148.3
Public Utilities, Property, Plant and Equipment, Amount of Acquisition Adjustments, Related Accumulated Depreciation	83.8	78.3
Electric Transmission [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Amount of Acquisition Adjustments	3.3	3.3
Public Utilities, Property, Plant and Equipment, Amount of Acquisition Adjustments, Related Accumulated Depreciation	$ 1.1	$ 1.0