CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY - USD ($) shares in Millions, $ in Millions	Total	OG&E [Member]	Common Stock	Common Stock OG&E [Member]	Premium on Common Stock	Premium on Common Stock OG&E [Member]	Retained Earnings	Retained Earnings OG&E [Member]	Accumulated Other Comprehensive (Loss) Income	Treasury Stock
Balance at Dec. 31, 2020	$ 3,631.8	$ 3,975.6	$ 2.0	$ 100.9	$ 1,122.6	$ 938.6	$ 2,544.6	$ 2,936.1	$ (32.1)	$ (5.3)
Common Stock, Shares, Outstanding at Dec. 31, 2020			200.1	40.4
Treasury Stock, Common, Shares at Dec. 31, 2020										0.1
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	737.3	360.0	$ 0.0	$ 0.0	0.0	0.0	737.3	360.0	0.0	$ 0.0
Net income, Number of Shares			0.0	0.0						0.0
Other comprehensive income, net of tax, Number of Shares			0.0							0.0
Other comprehensive income, net of tax	7.3	0.0	$ 0.0		0.0		0.0		7.3	$ 0.0
Dividends declared on common stock, Number of Shares			0.0	0.0						0.0
Dividends declared on common stock	(326.5)	(265.0)	$ 0.0	$ 0.0	0.0	0.0	(326.5)	(265.0)	0.0	$ 0.0
Capital contribution from OGE Energy		530.0		$ 0.0		530.0		0.0
Capital contribution from OGE Energy, Number of Shares				0.0
Stock-based compensation, Number of Shares			0.0	0.0						(0.1)
Stock-based compensation	6.4	2.2	$ 0.0	$ 0.0	1.2	2.2	0.0	0.0	0.0	$ 5.2
Balance at Dec. 31, 2021	4,056.3	4,602.8	$ 2.0	$ 100.9	1,123.8	1,470.8	2,955.4	3,031.1	(24.8)	$ (0.1)
Common Stock, Shares, Outstanding at Dec. 31, 2021			200.1	40.4
Treasury Stock, Common, Shares at Dec. 31, 2021										0.0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	665.7	439.5	$ 0.0	$ 0.0	0.0	0.0	665.7	439.5	0.0	$ 0.0
Net income, Number of Shares			0.0	0.0						0.0
Other comprehensive income, net of tax, Number of Shares			0.0							0.0
Other comprehensive income, net of tax	12.9	0.0	$ 0.0		0.0		0.0		12.9	$ 0.0
Dividends declared on common stock, Number of Shares			0.0							0.0
Dividends declared on common stock	(330.2)		$ 0.0		0.0		(330.2)		0.0	$ 0.0
Stock-based compensation, Number of Shares			0.1							0.0
Stock-based compensation	8.7	2.9	$ 0.0	$ 0.0	8.7	2.9	0.0	0.0	0.0	$ 0.0
Balance at Dec. 31, 2022	$ 4,413.4	$ 5,045.2	$ 2.0	$ 100.9	1,132.5	1,473.7	3,290.9	3,470.6	(11.9)	$ (0.1)
Common Stock, Shares, Outstanding at Dec. 31, 2022	200.2	40.4	200.2	40.4
Treasury Stock, Common, Shares at Dec. 31, 2022	0.0									0.0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 416.8	$ 426.4	$ 0.0	$ 0.0	0.0	0.0	416.8	426.4	0.0	$ 0.0
Net income, Number of Shares			0.0	0.0						0.0
Other comprehensive income, net of tax, Number of Shares			0.0							0.0
Other comprehensive income, net of tax	4.7	0.0	$ 0.0		0.0		0.0		4.7	$ 0.0
Dividends declared on common stock, Number of Shares			0.0	0.0						0.0
Dividends declared on common stock	(334.0)	(500.0)	$ 0.0	$ 0.0	0.0	0.0	(334.0)	(500.0)	0.0	$ 0.0
Stock-based compensation, Number of Shares			0.1	0.0						0.0
Stock-based compensation	10.7	3.1	$ 0.0	$ 0.0	10.6	3.1	0.0	0.0	0.0	$ 0.1
Balance at Dec. 31, 2023	$ 4,511.6	$ 4,974.7	$ 2.0	$ 100.9	$ 1,143.1	$ 1,476.8	$ 3,373.7	$ 3,397.0	$ (7.2)	$ 0.0
Common Stock, Shares, Outstanding at Dec. 31, 2023	200.3	40.4	200.3	40.4
Treasury Stock, Common, Shares at Dec. 31, 2023	0.0									0.0