Pensions and Postretirement Benefits - Summary of Change in Defined Benefit and Postretirement Benefit Plans (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Change in plan assets
Fair value of plan assets at beginning of year	$ 147.9
Fair value of plan assets at end of year	156.1	$ 147.9
Funded (underfunded) status of the plans
Pension assets	85.3	75.1
Pension Benefits
Change in benefit obligation
Benefit obligation at beginning of year	72.8	67.6
Service costs	4.3	4.3	$ 4.3
Interest costs	3.4	3.5	1.8
Actuarial (gain) loss	(1.2)	3.2
Benefits and expenses paid	(8.5)	(6.2)
Curtailment loss - discontinued operations	0.0	0.4	0.0
Benefit obligation at end of year	70.8	72.8	67.6
Change in plan assets
Fair value of plan assets at beginning of year	147.9	131.5
Actual return on plan assets	16.7	22.6
Benefits and expenses paid	(8.5)	(6.2)
Fair value of plan assets at end of year	156.1	147.9	131.5
Funded (underfunded) status of the plans	85.3	75.1
Funded (underfunded) status of the plans
Pension assets	85.3	75.1
Other long-term liabilities	0.0	0.0
Asset (liability), defined benefit plan	(85.3)	(75.1)
Amounts recognized in Accumulated other comprehensive loss
Net actuarial loss	17.7	26.8
Net prior service cost	0.1	0.1
Accumulated other comprehensive loss	17.8	26.9
Postretirement Benefits
Change in benefit obligation
Benefit obligation at beginning of year	5.0	5.2
Service costs	0.0	0.0	0.0
Interest costs	0.2	0.3	0.1
Actuarial (gain) loss	(0.5)	0.2
Benefits and expenses paid	(0.7)	(0.7)
Curtailment loss - discontinued operations	0.0	0.0	0.0
Benefit obligation at end of year	4.0	5.0	5.2
Change in plan assets
Fair value of plan assets at beginning of year	3.4	3.6
Actual return on plan assets	0.4	0.5
Benefits and expenses paid	(0.7)	(0.7)
Fair value of plan assets at end of year	3.1	3.4	$ 3.6
Funded (underfunded) status of the plans	(0.9)	(1.6)
Funded (underfunded) status of the plans
Pension assets	0.0	0.0
Other long-term liabilities	0.9	1.6
Asset (liability), defined benefit plan	0.9	1.6
Amounts recognized in Accumulated other comprehensive loss
Net actuarial loss	1.0	2.0
Net prior service cost	0.0	0.0
Accumulated other comprehensive loss	$ 1.0	$ 2.0