Report of Business Segments - Summary of OGE Energy's Business Segments (Details) - USD ($) $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2024	Mar. 31, 2024	Jun. 30, 2023	Mar. 31, 2023	Jun. 30, 2024	Jun. 30, 2023	Dec. 31, 2023
Segment Reporting Information [Line Items]
Operating revenues	$ 662.6		$ 605.0		$ 1,259.4	$ 1,162.2
Fuel, purchased power and direct transmission expense	193.9		181.8		426.1	382.4
Other operation and maintenance	130.4		128.3		262.8	258.7
Depreciation and amortization	135.5		124.1		264.7	245.3
Taxes other than income	26.9		24.4		55.9	52.9
OPERATING INCOME	175.9		146.4		249.9	222.9
Other income	10.5		14.5		16.9	30.9
Interest expense	64.9		57.7		125.1	105.5
Income tax expense (benefit)	19.2		14.8		20.8	21.6
Net income (loss)	102.3	$ 18.6	88.4	$ 38.3	120.9	126.7
Total assets	13,211.8		12,604.6		13,211.8	12,604.6	$ 12,790.7
Operating Segments [Member] | Electric Company [Member]
Segment Reporting Information [Line Items]
Operating revenues	662.6		605.0		1,259.4	1,162.2
Fuel, purchased power and direct transmission expense	193.9		181.8		426.1	382.4
Other operation and maintenance	130.2		128.6		262.6	260.1
Depreciation and amortization	135.5		124.1		264.7	245.3
Taxes other than income	26.9		23.5		55.9	50.6
OPERATING INCOME	176.1		147.0		250.1	223.8
Other income	10.2		13.2		16.8	28.5
Interest expense	54.9		52.1		106.3	97.8
Income tax expense (benefit)	22.1		16.2		26.1	22.8
Net income (loss)	109.3		91.9		134.5	131.7
Total assets	13,073.1		12,492.9		13,073.1	12,492.9
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	0.2		(0.3)		0.2	(1.4)
Depreciation and amortization	0.0		0.0		0.0	0.0
Taxes other than income	0.0		0.9		0.0	2.3
OPERATING INCOME	(0.2)		(0.6)		(0.2)	(0.9)
Other income	1.7		4.4		3.2	8.9
Interest expense	11.4		8.7		21.9	14.2
Income tax expense (benefit)	(2.9)		(1.4)		(5.3)	(1.2)
Net income (loss)	(7.0)		(3.5)		(13.6)	(5.0)
Total assets	323.5		686.8		323.5	686.8
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	(1.4)		(3.1)		(3.1)	(6.5)
Interest expense	(1.4)		(3.1)		(3.1)	(6.5)
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	$ (184.8)		$ (575.1)		$ (184.8)	$ (575.1)