Retirement Plans and Postretirement Benefit Plans - Schedule of Capitalized Pension and Postretirement Cost (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Capitalized portion of net periodic pension benefit cost	$ 0.6	$ 0.5	$ 1.2	$ 1.1
Pension Plan [Member] | OG&E [Member]
Defined Benefit Plan Disclosure [Line Items]
Capitalized portion of net periodic pension benefit cost	0.6	0.5	1.2	1.1
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Capitalized portion of net periodic pension benefit cost	0.0	0.1	0.0	0.1
Other Postretirement Benefits Plan [Member] | OG&E [Member]
Defined Benefit Plan Disclosure [Line Items]
Capitalized portion of net periodic pension benefit cost	$ 0.0	$ 0.1	$ 0.0	$ 0.1