Other Income (Expense), Net - Components of Other Income (Expense), Net (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Other Income and Expenses [Abstract]
Interest income		$ 0.9	$ 0.6	$ 3.0	$ 1.2
Net periodic postretirement benefit cost		(1.5)	(2.2)	(3.3)	(6.1)
Unrealized gain (loss) on equity securities		0.2	(0.1)	0.5	0.2
Gain (loss) on disposition of property, plant and equipment		4.4	(0.2)	3.9	14.0
Gain on business interruption insurance recoveries	[1]	4.6	0.0	15.1	0.0
All other, net		0.1	(0.3)	(0.1)	(0.4)
Other income (expense), net		$ 8.7	$ (2.2)	$ 19.1	$ 8.9

[1] Represents advances against business interruption insurance claims. We recognize such advances in the period in which the insurance proceeds are received or become realizable. As of September 30, 2024, we received net cash proceeds of $13.4 million.