Report of Business Segments - Summary of OGE Energy's Business Segments (Details) - USD ($) $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2025	Mar. 31, 2025	Jun. 30, 2024	Mar. 31, 2024	Jun. 30, 2025	Jun. 30, 2024	Dec. 31, 2024
Segment Reporting Information [Line Items]
Operating revenues	$ 741.6		$ 662.6		$ 1,489.3	$ 1,259.4
Fuel, purchased power and direct transmission expense	261.1		193.9		585.1	426.1
Other operation and maintenance	127.1		130.4		248.9	262.8
Depreciation and amortization	140.6		135.5		278.0	264.7
Taxes other than income	26.2		26.9		57.4	55.9
OPERATING INCOME	186.6		175.9		319.9	249.9
Other income	15.1		10.5		22.0	16.9
Interest expense	72.2		64.9		139.5	125.1
Income tax expense (benefit)	22.0		19.2		32.2	20.8
Net income (loss)	107.5	$ 62.7	102.3	$ 18.6	170.2	120.9
Total assets	14,089.1		13,211.8		14,089.1	13,211.8	$ 13,716.0
Capital expenditures	273.7		323.3		523.2	550.2
Operating Segments [Member] | Electric Company [Member]
Segment Reporting Information [Line Items]
Operating revenues	741.6		662.6		1,489.3	1,259.4
Fuel, purchased power and direct transmission expense	261.1		193.9		585.1	426.1
Other operation and maintenance	126.3		130.2		248.1	262.6
Depreciation and amortization	140.6		135.5		278.0	264.7
Taxes other than income	26.2		26.9		57.4	55.9
OPERATING INCOME	187.4		176.1		320.7	250.1
Other income	7.0		10.2		15.9	16.8
Interest expense	63.4		54.9		120.2	106.3
Income tax expense (benefit)	23.3		22.1		37.7	26.1
Net income (loss)	107.7		109.3		178.7	134.5
Total assets	13,990.8		13,073.1		13,990.8	13,073.1
Capital expenditures	273.7		323.3		523.2	550.2
Operating Segments [Member] | Other Operations [Member]
Segment Reporting Information [Line Items]
Operating revenues	0.0		0.0		0.0	0.0
Fuel, purchased power and direct transmission expense	0.0		0.0		0.0	0.0
Other operation and maintenance	0.8		0.2		0.8	0.2
Depreciation and amortization	0.0		0.0		0.0	0.0
Taxes other than income	0.0		0.0		0.0	0.0
OPERATING INCOME	(0.8)		(0.2)		(0.8)	(0.2)
Other income	9.0		1.7		10.2	3.2
Interest expense	9.7		11.4		23.4	21.9
Income tax expense (benefit)	(1.3)		(2.9)		(5.5)	(5.3)
Net income (loss)	(0.2)		(7.0)		(8.5)	(13.6)
Total assets	140.4		323.5		140.4	323.5
Capital expenditures	0.0		0.0		0.0	0.0
Eliminations [Member]
Segment Reporting Information [Line Items]
Operating revenues	0.0		0.0		0.0	0.0
Fuel, purchased power and direct transmission expense	0.0		0.0		0.0	0.0
Other operation and maintenance	0.0		0.0		0.0	0.0
Depreciation and amortization	0.0		0.0		0.0	0.0
Taxes other than income	0.0		0.0		0.0	0.0
OPERATING INCOME	0.0		0.0		0.0	0.0
Other income	(0.9)		(1.4)		(4.1)	(3.1)
Interest expense	(0.9)		(1.4)		(4.1)	(3.1)
Income tax expense (benefit)	0.0		0.0		0.0	0.0
Net income (loss)	0.0		0.0		0.0	0.0
Total assets	(42.1)		(184.8)		(42.1)	(184.8)
Capital expenditures	$ 0.0		$ 0.0		$ 0.0	$ 0.0