CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (Unaudited) - USD ($) $ 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 Income (Loss)	Treasury Stock [Member]
Changes in Stockholders' Equity
Balance	$ 4,139.5		$ 2.0		$ 1,129.3		$ 3,036.1		$ (27.9)	$ 0.0
Common Stock, Shares, Outstanding			200,100,000	40,400,000
Treasury Stock, Common, Shares										0
Stockholders' Equity Attributable to Parent		$ 3,958.3		$ 100.9		$ 935.7		$ 2,921.7
Net Income (Loss), Including portion attributable to noncontrolling interest, Number of Shares			0	0						0
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	(491.8)		$ 0.0		0.0		(491.8)		0.0	$ 0.0
Other Comprehensive Income (Loss), Net of Tax, Number of Shares			0							0
Dividends, Common Stock, Cash, Number of Shares			0							0
Other comprehensive loss, net of tax	(0.9)		$ 0.0		0.0		0.0		(0.9)	$ 0.0
Dividends, Common Stock, Cash	(79.3)		$ 0.0		0.0		(79.3)		0.0	$ 0.0
Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition, Number of Shares			0	0						(200,000)
Stock-based compensation	(5.1)	0.9	$ 0.0	$ 0.0	(14.5)	0.9	0.0	0.0	0.0	$ 9.4
Treasury Stock, Shares, Acquired			0							200,000
Treasury Stock, Value, Acquired, Cost Method	(9.7)		$ 0.0		0.0		0.0		0.0	$ (9.7)
Net Income (Loss) Attributable to Parent		19.9		$ 0.0		0.0		19.9
Proceeds from Contributed Capital		0.0
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	(228.5)						(228.5)
Other comprehensive loss, net of tax	2.2	0.0
Net Income (Loss) Attributable to Parent	(228.5)	298.3
Balance	3,552.7		$ 2.0		1,114.8		2,465.0		(28.8)	$ (0.3)
Common Stock, Shares, Outstanding			200,100,000	40,400,000
Treasury Stock, Common, Shares										0
Stockholders' Equity Attributable to Parent		3,979.1		$ 100.9		936.6		2,941.6
Net Income (Loss), Including portion attributable to noncontrolling interest, Number of Shares			0	0						0
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	85.9		$ 0.0		0.0		85.9		0.0	$ 0.0
Other Comprehensive Income (Loss), Net of Tax, Number of Shares			0							0
Dividends, Common Stock, Cash, Number of Shares			0	0						0
Other comprehensive loss, net of tax	0.9		$ 0.0		0.0		0.0		0.9	$ 0.0
Dividends, Common Stock, Cash	(77.6)		$ 0.0		0.0		(77.6)		0.0	$ 0.0
Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition, Number of Shares			0	0						0
Stock-based compensation	2.3	0.7	$ 0.0	$ 0.0	2.3	0.7	0.0	0.0	0.0	$ 0.0
Net Income (Loss) Attributable to Parent		78.9		0.0		0.0		78.9
Dividends, Common Stock		(75.0)		$ 0.0		0.0		(75.0)
Balance	3,564.2		$ 2.0		1,117.1		2,473.3		(27.9)	$ (0.3)
Common Stock, Shares, Outstanding			200,100,000	40,400,000
Treasury Stock, Common, Shares										0
Stockholders' Equity Attributable to Parent		3,983.7		$ 100.9		937.3		2,945.5
Net Income (Loss), Including portion attributable to noncontrolling interest, Number of Shares			0	0
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	177.4		$ 0.0		0.0		177.4		0.0
Other Comprehensive Income (Loss), Net of Tax, Number of Shares			0
Dividends, Common Stock, Cash, Number of Shares			0	0
Other comprehensive loss, net of tax	2.2	0.0	$ 0.0		0.0		0.0		2.2
Dividends, Common Stock, Cash	(80.5)		$ 0.0		0.0		(80.5)		0.0
Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition, Number of Shares			0	0
Stock-based compensation	2.4	0.6	$ 0.0	$ 0.0	2.4	0.6	0.0	0.0	0.0
Treasury Stock, Shares, Acquired			0							100,000
Treasury Stock, Value, Acquired, Cost Method	(5.0)		$ 0.0		0.0		0.0		0.0	$ (5.0)
Net Income (Loss) Attributable to Parent	177.4	199.5		0.0		0.0		199.5
Dividends, Common Stock		(250.0)		$ 0.0		0.0		(250.0)
Balance	3,660.7		$ 2.0		1,119.5		2,570.2		(25.7)	$ (5.3)
Common Stock, Shares, Outstanding			200,100,000	40,400,000
Treasury Stock, Common, Shares										100,000
Stockholders' Equity Attributable to Parent		3,933.8		$ 100.9		937.9		2,895.0
Balance	3,631.8		$ 2.0		1,122.6		2,544.6		(32.1)	$ (5.3)
Common Stock, Shares, Outstanding			200,100,000	40,400,000
Treasury Stock, Common, Shares										100,000
Stockholders' Equity Attributable to Parent	3,631.8	3,975.6		$ 100.9		938.6		2,936.1
Net Income (Loss), Including portion attributable to noncontrolling interest, Number of Shares			0	0						0
Proceeds From Contributed Capital, Shares				0
Proceeds from Contributed Capital	530.0	530.0		$ 0.0				0.0
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	52.7		$ 0.0		0.0		52.7		0.0	$ 0.0
Other Comprehensive Income (Loss), Net of Tax, Number of Shares			0							0
Dividends, Common Stock, Cash, Number of Shares			0							0
Other comprehensive loss, net of tax	3.5		$ 0.0		0.0		0.0		3.5	$ 0.0
Dividends, Common Stock, Cash	(81.7)		$ 0.0		0.0		(81.7)		0.0	$ 0.0
Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition, Number of Shares			0	0						(100,000)
Stock-based compensation	(0.8)	0.5	$ 0.0	$ 0.0	(6.0)	0.5	0.0	0.0	0.0	$ 5.2
Net Income (Loss) Attributable to Parent		11.2		$ 0.0		0.0		11.2
Proceeds from Contributed Capital		530.0
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	418.1						418.1
Other comprehensive loss, net of tax	$ 5.8	0.0
Treasury Stock, Shares, Acquired	154,523
Net Income (Loss) Attributable to Parent	$ 418.1	320.1
Balance	3,605.5		$ 2.0		1,116.6		2,515.6		(28.6)	$ (0.1)
Common Stock, Shares, Outstanding			200,100,000	40,400,000
Treasury Stock, Common, Shares										0
Stockholders' Equity Attributable to Parent		4,517.3		$ 100.9		1,469.1		2,947.3
Net Income (Loss), Including portion attributable to noncontrolling interest, Number of Shares			0	0						0
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	112.9		$ 0.0		0.0		112.9		0.0	$ 0.0
Other Comprehensive Income (Loss), Net of Tax, Number of Shares			0							0
Dividends, Common Stock, Cash, Number of Shares			0	0						0
Other comprehensive loss, net of tax	0.7		$ 0.0		0.0		0.0		0.7	$ 0.0
Dividends, Common Stock, Cash	(80.6)		$ 0.0		0.0		(80.6)		0.0	$ 0.0
Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition, Number of Shares			0	0						0
Stock-based compensation	2.3	0.6	$ 0.0	$ 0.0	2.3	0.6	0.0	0.0	0.0	$ 0.0
Net Income (Loss) Attributable to Parent		85.1		0.0		0.0		85.1
Dividends, Common Stock		(45.0)		$ 0.0		0.0		(45.0)
Balance	3,640.8		$ 2.0		1,118.9		2,547.9		(27.9)	$ (0.1)
Common Stock, Shares, Outstanding			200,100,000	40,400,000
Treasury Stock, Common, Shares										0
Stockholders' Equity Attributable to Parent		4,558.0		$ 100.9		1,469.7		2,987.4
Net Income (Loss), Including portion attributable to noncontrolling interest, Number of Shares			0	0						0
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	252.5		$ 0.0		0.0		252.5		0.0	$ 0.0
Other Comprehensive Income (Loss), Net of Tax, Number of Shares			0							0
Dividends, Common Stock, Cash, Number of Shares			0	0						0
Other comprehensive loss, net of tax	1.6	0.0	$ 0.0		0.0		0.0		1.6	$ 0.0
Dividends, Common Stock, Cash	(82.1)		$ 0.0		0.0		(82.1)		0.0	$ 0.0
Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition, Number of Shares			0	0						0
Stock-based compensation	2.1	0.6	$ 0.0	$ 0.0	2.1	0.6	0.0	0.0	0.0	$ 0.0
Net Income (Loss) Attributable to Parent	252.5	223.8		0.0		0.0		223.8
Dividends, Common Stock		(220.0)		$ 0.0		0.0		(220.0)
Balance	3,814.9		$ 2.0		$ 1,121.0		$ 2,718.3		$ (26.3)	$ (0.1)
Common Stock, Shares, Outstanding			200,100,000	40,400,000
Treasury Stock, Common, Shares										0
Stockholders' Equity Attributable to Parent	$ 3,814.9	$ 4,562.4		$ 100.9		$ 1,470.3		$ 2,991.2