Defined Benefit Pension Plans and Other Post-Employment Benefit Plans - Schedule of Net Period Benefit Costs (Income) for Post-retirement Employee Benefit Plans (Details) - USD ($) $ in Millions |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2025 |
Jun. 30, 2024 |
Jun. 30, 2025 |
Jun. 30, 2024 |
|
| Components of net periodic benefit cost: | ||||
| Interest cost | $ 6.3 | $ 6.9 | $ 12.6 | $ 13.6 |
| Amortization of net prior service credit and net actuarial gain | 0.1 | 0.1 | ||
| Net periodic benefit cost | 0.7 | 1.8 | 1.7 | 3.4 |
| Other post-retirement employee benefit plans | ||||
| Components of net periodic benefit cost: | ||||
| Interest cost | 0.4 | 0.3 | 0.7 | 0.7 |
| Amortization of net prior service credit and net actuarial gain | (0.1) | (0.2) | (0.3) | (0.3) |
| Net periodic benefit cost | $ 0.3 | $ 0.1 | $ 0.4 | $ 0.4 |