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Retirement Plans and Postretirement Benefit Plans - Schedule of Accumulated Benefit Obligations in Excess of Fair Value of Plan Assets (Details) - USD ($)
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]      
Employer contributions $ 10,000,000 $ 0  
Pension Plan [Member]      
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]      
Benefit Obligation, Beginning 303,700,000 358,500,000  
Service cost 5,300,000 5,400,000 $ 7,600,000
Interest cost 15,600,000 15,900,000 15,700,000
Plan settlements 0 (62,800,000)  
Regulatory classification of certain pension costs 0 0  
Actuarial losses (gains) (2,900,000) 800,000  
Benefits paid (18,600,000) (14,100,000)  
Benefit Obligation, Ending 303,100,000 303,700,000 358,500,000
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]      
Fair Value of Plan Assets, Beginning 243,700,000 293,000,000  
Actual return on plans' assets 11,800,000 27,600,000  
Employer contributions 10,000,000 0  
Regulatory classification of certain pension costs 0 0  
Plan settlements 0 (62,800,000)  
Benefits paid (18,600,000) (14,100,000)  
Fair Value of Plan Assets, Ending 246,900,000 243,700,000 293,000,000
Funded status at end of year (56,200,000) (60,000,000)  
Accumulated Benefit Obligation (289,400,000) (289,500,000)  
Pension Plan [Member] | Og and E [Member]      
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]      
Benefit Obligation, Beginning 238,600,000 288,500,000  
Service cost 5,300,000 4,400,000 6,200,000
Interest cost 13,400,000 12,600,000 12,100,000
Plan settlements 0 (57,700,000)  
Regulatory classification of certain pension costs 23,900,000 0  
Actuarial losses (gains) (2,200,000) 2,700,000  
Benefits paid (15,100,000) (11,900,000)  
Benefit Obligation, Ending 263,900,000 238,600,000 288,500,000
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]      
Fair Value of Plan Assets, Beginning 191,400,000 238,900,000  
Actual return on plans' assets 10,100,000 22,100,000  
Employer contributions 10,000,000 0  
Regulatory classification of certain pension costs 15,200,000 0  
Plan settlements 0 (57,700,000)  
Benefits paid (15,100,000) (11,900,000)  
Fair Value of Plan Assets, Ending 211,600,000 191,400,000 238,900,000
Funded status at end of year (52,300,000) (47,200,000)  
Accumulated Benefit Obligation (250,200,000) (226,500,000)  
Restoration of Retirement Income Plan [Member]      
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]      
Benefit Obligation, Beginning 5,500,000 5,800,000  
Service cost 1,000,000 1,000,000 1,100,000
Interest cost 300,000 300,000 200,000
Plan settlements 0 (1,400,000)  
Regulatory classification of certain pension costs 0 0  
Actuarial losses (gains) 200,000 (200,000)  
Benefits paid 0 0  
Benefit Obligation, Ending 7,000,000 5,500,000 5,800,000
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]      
Fair Value of Plan Assets, Beginning 0 0  
Actual return on plans' assets 0 0  
Employer contributions 0 1,400,000  
Regulatory classification of certain pension costs 0    
Plan settlements 0 (1,400,000)  
Benefits paid 0 0  
Fair Value of Plan Assets, Ending 0 0 0
Funded status at end of year (7,000,000) (5,500,000)  
Accumulated Benefit Obligation (6,800,000) (4,900,000)  
Restoration of Retirement Income Plan [Member] | Og and E [Member]      
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]      
Benefit Obligation, Beginning 0 500,000  
Service cost 100,000 0 0
Interest cost 100,000 0 0
Plan settlements 0 (700,000)  
Regulatory classification of certain pension costs 1,100,000 0  
Actuarial losses (gains) 100,000 200,000  
Benefits paid 0 0  
Benefit Obligation, Ending 1,400,000 0 500,000
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]      
Fair Value of Plan Assets, Beginning 0 0  
Actual return on plans' assets 0 0  
Employer contributions 0 700,000  
Regulatory classification of certain pension costs 0 0  
Plan settlements 0 (700,000)  
Benefits paid 0 0  
Fair Value of Plan Assets, Ending 0 0 0
Funded status at end of year (1,400,000) 0  
Accumulated Benefit Obligation (1,400,000) 0  
Other Postretirement Benefits Plan [Member]      
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]      
Benefit Obligation, Beginning 103,300,000 101,900,000  
Service cost 100,000 100,000 200,000
Interest cost 5,200,000 5,200,000 3,500,000
Participants' contributions 3,500,000 3,400,000  
Regulatory classification of certain pension costs 0 0  
Actuarial losses (gains) (3,100,000) 4,900,000  
Benefits paid (10,900,000) (12,200,000)  
Benefit Obligation, Ending 98,100,000 103,300,000 101,900,000
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]      
Fair Value of Plan Assets, Beginning 32,700,000 32,800,000  
Actual return on plans' assets (1,600,000) 1,900,000  
Employer contributions 6,300,000 6,800,000  
Participants' contributions 3,500,000 3,400,000  
Benefits paid (10,900,000) (12,200,000)  
Fair Value of Plan Assets, Ending 30,000,000 32,700,000 32,800,000
Accumulated Benefit Obligation (68,100,000) (70,600,000)  
Other Postretirement Benefits Plan [Member] | Og and E [Member]      
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]      
Benefit Obligation, Beginning 77,300,000 76,400,000  
Service cost 100,000 100,000 100,000
Interest cost 3,900,000 3,900,000 2,700,000
Participants' contributions 2,400,000 2,400,000  
Regulatory classification of certain pension costs 1,400,000 0  
Actuarial losses (gains) (2,100,000) 4,000,000  
Benefits paid (8,300,000) (9,500,000)  
Benefit Obligation, Ending 74,700,000 77,300,000 76,400,000
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]      
Fair Value of Plan Assets, Beginning 29,600,000 29,800,000  
Actual return on plans' assets (1,400,000) 1,700,000  
Employer contributions 4,900,000 5,200,000  
Participants' contributions 2,400,000 2,400,000  
Benefits paid (8,300,000) (9,500,000)  
Fair Value of Plan Assets, Ending 27,200,000 29,600,000 $ 29,800,000
Accumulated Benefit Obligation $ (47,500,000) $ (47,700,000)