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
Proceeds from Contributed Capital		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		0.0		(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	(491.8)	19.9		$ 0.0		0.0		19.9
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
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		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
Treasury Stock, Shares, Acquired	153,964
Treasury Stock, Value, Acquired, Cost Method	$ 0.0
Net Income (Loss) Attributable to Parent	52.7	11.2		$ 0.0		0.0		11.2
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	$ 3,605.5	$ 4,517.3		$ 100.9		$ 1,469.1		$ 2,947.3