v3.25.4
Postretirement Benefits Other Than Pensions - Changes in Fair Value of Plan Assets and Changes in Accumulated Benefit Obligations (Details) - Other Postretirement Benefit Plan, Defined Benefit - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]      
Fair Value of Plan Assets at Beginning of Year $ 0.0 $ 0.0  
Employer Contributions 0.5 0.4  
Plan Participants’ Contributions 0.1 0.1  
Benefits Paid (0.6) (0.5)  
Fair Value of Plan Assets at End of Year 0.0 0.0 $ 0.0
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]      
Projected Benefit Obligation at Beginning of Year 6.5 7.5  
Service Cost 0.1 0.1 0.1
Interest Cost 0.3 0.3 0.4
Plan Participants’ Contributions 0.1 0.1  
Benefits Paid (0.6) (0.5)  
Actuarial Gains (0.2) (1.0)  
Projected Benefit Obligation at End of Year 6.2 6.5 $ 7.5
Funded Status—Plan Assets in Excess of Projected Benefit Obligation (6.2) (6.5)  
Unamortized Actuarial Gain Reported in AOCI at End of Year $ 10.1 $ 12.0