Commitments and Contingencies (Details) $ in Millions	12 Months Ended
	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Loss Contingencies [Line Items]
Operating Leases, Future Minimum Payments Due, Next Twelve Months	$ 156.0
Operating Leases, Future Minimum Payments, Due in Two Years	109.0
Operating Leases, Future Minimum Payments, Due in Three Years	102.8
Operating Leases, Future Minimum Payments, Due in Four Years	105.9
Operating Leases, Future Minimum Payments, Due in Five Years	91.7
Operating Leases, Future Minimum Payments Due	565.4
Utilities Operating Expense, Purchased Power under Long-term Contracts	55.8	$ 57.3	$ 57.7
OG&E minimum fuel purchase commitments [Member]
Loss Contingencies [Line Items]
Operating Leases, Future Minimum Payments Due	228.5
Purchase Obligation, Due in Next Twelve Months	97.7
Unrecorded Unconditional Purchase Obligation, Due within Two Years	50.4
Unrecorded Unconditional Purchase Obligation, Due within Three Years	31.2
Unrecorded Unconditional Purchase Obligation, Due within Four Years	24.6
Unrecorded Unconditional Purchase Obligation, Due within Five Years	24.6
OG&E expected wind purchase commitments [Member]
Loss Contingencies [Line Items]
Operating Leases, Future Minimum Payments Due	282.5
Purchase Obligation, Due in Next Twelve Months	55.6
Unrecorded Unconditional Purchase Obligation, Due within Two Years	56.0
Unrecorded Unconditional Purchase Obligation, Due within Three Years	56.6
Unrecorded Unconditional Purchase Obligation, Due within Four Years	56.9
Unrecorded Unconditional Purchase Obligation, Due within Five Years	57.4
OG&E long-term service agreement commitments [Member]
Loss Contingencies [Line Items]
Operating Leases, Future Minimum Payments Due	54.4
Purchase Obligation, Due in Next Twelve Months	2.7
Unrecorded Unconditional Purchase Obligation, Due within Two Years	2.6
Unrecorded Unconditional Purchase Obligation, Due within Three Years	15.0
Unrecorded Unconditional Purchase Obligation, Due within Four Years	24.4
Unrecorded Unconditional Purchase Obligation, Due within Five Years	9.7
OG&E total cogeneration payments [Member]
Loss Contingencies [Line Items]
Utilities Operating Expense, Purchased Power under Long-term Contracts		14.7
OG&E capacity payments [Member]
Loss Contingencies [Line Items]
Utilities Operating Expense, Purchased Power under Long-term Contracts		7.4
CPV Keenan [Member]
Loss Contingencies [Line Items]
Utilities Operating Expense, Purchased Power under Long-term Contracts	27.3	27.5	27.2
Edison Mission Energy [Member]
Loss Contingencies [Line Items]
Utilities Operating Expense, Purchased Power under Long-term Contracts	21.7	22.8	23.1
NextEra Energy [Member]
Loss Contingencies [Line Items]
Utilities Operating Expense, Purchased Power under Long-term Contracts	$ 6.8	$ 7.0	$ 7.4
OG&E long-term service agreement commitments [Member] | McClain Plant [Member]
Loss Contingencies [Line Items]
Factored-Fired Hours	128,000
Factored-Fired Starts	4,800
OG&E long-term service agreement commitments [Member] | Redbud Plant [Member]
Loss Contingencies [Line Items]
Factored-Fired Hours	144,000
Factored-Fired Starts	4,500
Additional Factored-Fired Hours	24,000