v3.26.1
Retirement Benefits - Schedule of Components of Net Periodic Benefit Cost (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Mar. 31, 2025
Jun. 30, 2026
Jun. 30, 2025
Pension Benefits:          
Defined Benefit Plan Disclosure [Line Items]          
Service cost $ 0.1 $ 0.0   $ 0.1 $ 0.0
Interest cost 0.1 2.9   0.2 5.7
Expected return on plan assets (0.1) (2.3)   (0.1) (4.6)
Curtailment 0.0 0.0 $ (0.7) 0.0 (0.7)
Net periodic benefit cost 0.1 0.6   0.2 0.4
Other Postretirement Benefits:          
Defined Benefit Plan Disclosure [Line Items]          
Interest cost 0.1 0.1   0.2 0.2
Net periodic benefit cost $ 0.1 $ 0.1   $ 0.2 $ 0.2