Stockholders' Equity - Changes in Each Component of Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2025	Mar. 31, 2024	Dec. 31, 2024	Dec. 31, 2023
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	$ (89.0)
Net current-period other comprehensive income (loss)	4.3	$ (2.8)
Ending balance	(84.7)
Actuarial Losses
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Accumulated Other Comprehensive Income (Loss)	(62.3)	(69.1)	$ (62.5)	$ (69.7)
Other comprehensive (loss) income before reclassifications	(0.3)	0.1
Amounts reclassified from accumulated other comprehensive loss	0.5	0.5
Net current-period other comprehensive income (loss)	0.2	0.6
Prior Service Costs
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Accumulated Other Comprehensive Income (Loss)	(1.8)	(2.0)	(1.8)	(2.0)
Other comprehensive (loss) income before reclassifications	0.0	0.0
Amounts reclassified from accumulated other comprehensive loss	0.0	0.0
Net current-period other comprehensive income (loss)	0.0	0.0
Currency Translation
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Accumulated Other Comprehensive Income (Loss)	(20.5)	(14.0)	(24.5)	(10.1)
Other comprehensive (loss) income before reclassifications	4.0	(3.9)
Amounts reclassified from accumulated other comprehensive loss	0.0	0.0
Net current-period other comprehensive income (loss)	4.0	(3.9)
Interest Rate Swaps
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Accumulated Other Comprehensive Income (Loss)	(0.1)	1.0	(0.2)	0.5
Other comprehensive (loss) income before reclassifications	0.1	1.2
Amounts reclassified from accumulated other comprehensive loss	0.0	(0.7)
Net current-period other comprehensive income (loss)	0.1	0.5
Accumulated Other Comprehensive Loss
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Accumulated Other Comprehensive Income (Loss)	(84.7)	(84.1)	$ (89.0)	$ (81.3)
Other comprehensive (loss) income before reclassifications	3.8	(2.6)
Amounts reclassified from accumulated other comprehensive loss	0.5	(0.2)
Net current-period other comprehensive income (loss)	$ 4.3	$ (2.8)

Accumulated Other Comprehensive Income (Loss)

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Amount, after tax, of accumulated increase (decrease) in equity from transaction and other event and circumstance from nonowner source.

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Amount after tax, before reclassification adjustments, of other comprehensive income (loss), attributable to parent.

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Amount after tax of other comprehensive income (loss) attributable to parent entity.

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