Quarterly Financial Data (Tables)

12 Months Ended

Dec. 31, 2019

Quarterly Financial Data [Abstract]

Schedule of Quarterly Financial Information [Table Text Block]

Due to the seasonal fluctuations and other factors of OG&E's business, the operating results for interim periods are not necessarily indicative of the results that may be expected for the year. In OG&E's opinion, the following quarterly financial data includes all adjustments, consisting of normal recurring adjustments, necessary to fairly present such amounts. Summarized quarterly unaudited financial data is as follows:

Quarter Ended (In millions)		March 31		June 30		September 30		December 31		Total
Operating revenues	2019	$	490.0	$	513.7	$	755.4	$	472.5	$	2,231.6
	2018	$	492.7	$	567.0	$	698.8	$	511.8	$	2,270.3
Operating income	2019	$	50.3	$	110.6	$	275.0	$	71.8	$	507.7
	2018	$	67.1	$	138.3	$	230.3	$	58.5	$	494.2
Net income	2019	$	19.6	$	74.5	$	227.2	$	28.9	$	350.2
	2018	$	31.3	$	92.0	$	183.9	$	20.8	$	328.0