CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (Unaudited) - USD ($) $ in Millions	Total	OG&E [Member]	Common Stock	Common Stock OG&E [Member]	Treasury Stock	Premium on Common Stock	Premium on Common Stock OG&E [Member]	Retained Earnings	Retained Earnings OG&E [Member]	Accumulated Other Comprehensive (Loss) Income
Balance at Dec. 31, 2022	$ 4,413.4	$ 5,045.2	$ 2.0	$ 100.9	$ (0.1)	$ 1,132.5	$ 1,473.7	$ 3,290.9	$ 3,470.6	$ (11.9)
Common Stock, Shares, Outstanding at Dec. 31, 2022			200,200,000	40,400,000
Treasury Stock, Common, Shares at Dec. 31, 2022					0
Changes in Stockholders' Equity
Net income	38.3	39.8	$ 0.0	$ 0.0	$ 0.0	0.0	0.0	38.3	39.8	0.0
Net income, Number of Shares			0	0	0
Other comprehensive income, net of tax	1.1		$ 0.0		$ 0.0	0.0		0.0		1.1
Other comprehensive income, net of tax, Number of Shares			0		0
Dividends declared on common stock	(83.6)		$ 0.0		$ 0.0	0.0		(83.6)		0.0
Dividends declared on common stock, Number of Shares			0		0
Stock-based compensation	0.8	0.6	$ 0.0	$ 0.0	$ 0.1	0.7	0.6	0.0	0.0	0.0
Stock-based compensation, Number of Shares			100,000	0	0
Balance at Mar. 31, 2023	4,370.0	5,085.6	$ 2.0	$ 100.9	$ 0.0	1,133.2	1,474.3	3,245.6	3,510.4	(10.8)
Common Stock, Shares, Outstanding at Mar. 31, 2023			200,300,000	40,400,000
Treasury Stock, Common, Shares at Mar. 31, 2023					0
Balance at Dec. 31, 2022	4,413.4	5,045.2	$ 2.0	$ 100.9	$ (0.1)	1,132.5	1,473.7	3,290.9	3,470.6	(11.9)
Common Stock, Shares, Outstanding at Dec. 31, 2022			200,200,000	40,400,000
Treasury Stock, Common, Shares at Dec. 31, 2022					0
Changes in Stockholders' Equity
Net income	126.7	131.7						126.7
Other comprehensive income, net of tax		0.0
Balance at Jun. 30, 2023	4,379.1	4,928.4	$ 2.0	$ 100.9	$ 0.0	1,136.4	1,475.2	3,251.0	3,352.3	(10.3)
Common Stock, Shares, Outstanding at Jun. 30, 2023			200,300,000	40,400,000
Treasury Stock, Common, Shares at Jun. 30, 2023					0
Balance at Mar. 31, 2023	4,370.0	5,085.6	$ 2.0	$ 100.9	$ 0.0	1,133.2	1,474.3	3,245.6	3,510.4	(10.8)
Common Stock, Shares, Outstanding at Mar. 31, 2023			200,300,000	40,400,000
Treasury Stock, Common, Shares at Mar. 31, 2023					0
Changes in Stockholders' Equity
Net income	88.4	91.9	$ 0.0	$ 0.0	$ 0.0	0.0	0.0	88.4	91.9	0.0
Net income, Number of Shares			0	0	0
Other comprehensive income, net of tax	0.5	0.0	$ 0.0			0.0		0.0		0.5
Other comprehensive income, net of tax, Number of Shares			0		0
Dividends declared on common stock	(83.0)	(250.0)	$ 0.0	$ 0.0		0.0	0.0	(83.0)	(250.0)	0.0
Dividends declared on common stock, Number of Shares			0	0	0
Stock-based compensation	3.2	0.9	$ 0.0	$ 0.0	$ 0.0	3.2	0.9	0.0	0.0	0.0
Stock-based compensation, Number of Shares			0	0
Balance at Jun. 30, 2023	4,379.1	4,928.4	$ 2.0	$ 100.9	$ 0.0	1,136.4	1,475.2	3,251.0	3,352.3	(10.3)
Common Stock, Shares, Outstanding at Jun. 30, 2023			200,300,000	40,400,000
Treasury Stock, Common, Shares at Jun. 30, 2023					0
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)
Common Stock, Shares, Outstanding at Dec. 31, 2023			200,300,000	40,400,000
Changes in Stockholders' Equity
Net income	18.6	25.2	$ 0.0	$ 0.0		0.0	0.0	18.6	25.2	0.0
Net income, Number of Shares			0	0
Other comprehensive income, net of tax	3.9		$ 0.0			0.0		0.0		3.9
Other comprehensive income, net of tax, Number of Shares			0
Dividends declared on common stock	(86.1)		$ 0.0			0.0		(86.1)		0.0
Dividends declared on common stock, Number of Shares			0
Stock-based compensation	(2.7)	3.2	$ 0.0	$ 0.0		(2.7)	3.2	0.0	0.0	0.0
Stock-based compensation, Number of Shares			200,000	0
Balance at Mar. 31, 2024	4,445.3	5,003.1	$ 2.0	$ 100.9		1,140.4	1,480.0	3,306.2	3,422.2	(3.3)
Common Stock, Shares, Outstanding at Mar. 31, 2024			200,500,000	40,400,000
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)
Common Stock, Shares, Outstanding at Dec. 31, 2023			200,300,000	40,400,000
Changes in Stockholders' Equity
Net income	$ 120.9	134.5						120.9
Other comprehensive income, net of tax		0.0
Issuance of common stock, Number of Shares	255,578
Balance at Jun. 30, 2024	$ 4,477.7	5,115.8	$ 2.0	$ 100.9		1,154.5	1,483.4	3,324.4	3,531.5	(3.2)
Common Stock, Shares, Outstanding at Jun. 30, 2024			200,900,000	40,400,000
Balance at Mar. 31, 2024	4,445.3	5,003.1	$ 2.0	$ 100.9		1,140.4	1,480.0	3,306.2	3,422.2	(3.3)
Common Stock, Shares, Outstanding at Mar. 31, 2024			200,500,000	40,400,000
Changes in Stockholders' Equity
Net income	102.3	109.3	$ 0.0	$ 0.0		0.0	0.0	102.3	109.3	0.0
Net income, Number of Shares			0	0
Other comprehensive income, net of tax	0.1	0.0	$ 0.0			0.0		0.0		0.1
Other comprehensive income, net of tax, Number of Shares			0
Dividends declared on common stock	(84.1)		$ 0.0			0.0		(84.1)		0.0
Dividends declared on common stock, Number of Shares			0
Issuance of common stock	10.9		$ 0.0			10.9		0.0		0.0
Issuance of common stock, Number of Shares			400,000
Stock-based compensation	3.2	3.4	$ 0.0	$ 0.0		3.2	3.4	0.0	0.0	0.0
Stock-based compensation, Number of Shares			0	0
Balance at Jun. 30, 2024	$ 4,477.7	$ 5,115.8	$ 2.0	$ 100.9		$ 1,154.5	$ 1,483.4	$ 3,324.4	$ 3,531.5	$ (3.2)
Common Stock, Shares, Outstanding at Jun. 30, 2024			200,900,000	40,400,000