Stock-Based Compensation - Schedule of Pre-tax Compensation Expense and Related Income Tax Benefit (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total compensation expense	$ 13.1	$ 9.7	$ 9.8
Income tax benefit	3.2	2.3	2.5
OG&E [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total compensation expense	3.1	2.9	2.2
Income tax benefit	0.7	0.7	0.6
Performance Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total compensation expense	9.3	7.2	7.5
Performance Units [Member] | OG&E [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total compensation expense	2.2	2.2	1.8
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total compensation expense	3.8	2.5	2.3
Restricted Stock Units (RSUs) [Member] | OG&E [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total compensation expense	$ 0.9	$ 0.7	$ 0.4