Rate Matters and Regulation - Additional Information (Details) $ in Millions				12 Months Ended
	Jun. 12, 2024 USD ($)	Mar. 07, 2024 USD ($)	Dec. 29, 2023 USD ($)	Dec. 31, 2028 Megawattsday	Dec. 31, 2027 Megawattsday	Dec. 31, 2026 Megawattsday	Jun. 30, 2024 USD ($)
Estimated Refund to SPP							$ 13.0
Requested Recovery of Capital Investment			$ 1,300.0
Arkansas Public Service Commission [Member]
Public Utilities, Approved Rate Increase (Decrease), Amount		$ 3.5
Integrated Resource Plans [Member] | Forecast [Member]
Energy generation capacity | Megawattsday				1,096	431	556
OKLAHOMA [Member]
Public Utilities, Requested Rate Increase (Decrease), Amount	$ 126.7		$ 332.5
Public Utilities, Requested Return on Equity, Percentage			10.50%
Common Equity Percentage which ROE is based			53.50%
Impact to Company [Member]
Estimated Refund to SPP							5.0
Customer Impact [Member]
Estimated Refund to SPP							$ 8.0