Pensions and Postretirement Benefits - Summary of Components of Net Periodic Benefit Cost (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Pension Benefits
Components of net periodic benefit cost
Service costs	$ 4.3	$ 4.3	$ 4.3
Interest costs	3.4	3.5	1.8
Expected return on plan assets	(10.6)	(9.9)	(12.9)
Recognized net actuarial loss	1.8	3.6	0.0
Benefit (income) costs - continuing operations	(1.1)	1.5	(6.8)
Curtailment loss - discontinued operations	0.0	0.4	0.0
Total benefit (income) costs	(1.1)	1.9	(6.8)
Other changes in plan assets and benefit obligations recognized in accumulated other comprehensive loss (income) (“AOCI”)
AOCI at beginning of year	26.9	40.0	10.9
Net loss amortization	(1.8)	(3.7)	0.0
Recognition of actuarial (gain) loss	(7.3)	(9.4)	29.1
Total recognized in accumulated other comprehensive loss at end of year	17.8	26.9	40.0
Postretirement Benefits
Components of net periodic benefit cost
Service costs	0.0	0.0	0.0
Interest costs	0.2	0.3	0.1
Expected return on plan assets	(0.2)	(0.3)	(0.3)
Recognized net actuarial loss	0.2	0.3	0.2
Benefit (income) costs - continuing operations	0.2	0.3	0.0
Curtailment loss - discontinued operations	0.0	0.0	0.0
Total benefit (income) costs	0.2	0.3	0.0
Other changes in plan assets and benefit obligations recognized in accumulated other comprehensive loss (income) (“AOCI”)
AOCI at beginning of year	2.0	2.4	2.2
Net loss amortization	(0.2)	(0.3)	(0.2)
Recognition of actuarial (gain) loss	(0.8)	(0.1)	0.4
Total recognized in accumulated other comprehensive loss at end of year	$ 1.0	$ 2.0	$ 2.4