Revenue from Contracts with Customers (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021		Dec. 31, 2020	Dec. 31, 2019
Revenue from Contract with Customer, Excluding Assessed Tax	$ 3,588.7	[1]	$ 2,069.8	$ 2,175.5
Provision for Rate Refund [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	0.0		3.8	(0.9)
Integrated Market [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	468.9		49.6	38.4
Transmission [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	140.2		143.3	148.0
Other Contracts with Customers [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	1.1		30.7	29.1
Residential [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	1,309.1		842.7	865.8
Commercial [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	749.2		465.6	486.6
Industrial [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	323.0		192.6	217.8
Oilfield [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	312.8		169.2	200.4
Public Authority [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	284.4		172.3	190.3
Total Retail Customer [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 2,978.5		$ 1,842.4	$ 1,960.9

[1] In February 2021, Winter Storm Uri resulted in record winter peak demand for electricity and extremely high natural gas and purchased power prices in OG&E's service territory. Operating revenues significantly increased due to increased fuel, purchased power and direct transmission expenses, which are generally recoverable from customers, as a result of Winter Storm Uri. For further discussion, see Note 16 and "Item 7. Management's Discussion and Analysis of Financial Condition and Results of Operations."