Fair Value Measurements - Summary of Financial Instrument Measured at Fair Value On A Recurring Basis and Carrying Amount and Fair Value (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total long-term debt	$ 4,340.5	$ 4,548.6
OGE Energy Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total long-term debt	0.0	499.9
Long-Term Debt, Fair Value	0.0	491.2
OGE Energy Term Loan [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total long-term debt	49.9	49.8
Long-Term Debt, Fair Value	50.0	50.0
OG&E Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total long-term debt	4,146.0	3,854.2
Long-Term Debt, Fair Value	3,922.3	3,477.1
OG&E Industrial Authority Bonds [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total long-term debt	135.4	135.4
Long-Term Debt, Fair Value	135.4	135.4
Tinker Debt [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total long-term debt	9.2	9.3
Long-Term Debt, Fair Value	$ 7.1	$ 7.3