Rate Matters and Regulation - Additional Information (Details) $ in Millions		1 Months Ended	12 Months Ended
	Dec. 29, 2023 USD ($)	Oct. 31, 2023 USD ($)	Dec. 31, 2028 Megawattsday	Dec. 31, 2027 Megawattsday	Dec. 31, 2026 Megawattsday	Mar. 31, 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	$ 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