Other Expense, Net (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Other Income And Expenses [Abstract]
Interest income	$ 0.2		$ 0.2	$ 0.1
Net periodic postretirement benefit cost	(1.5)	$ (1.2)	(2.9)	(1.8)
Unrealized (loss) gain on equity securities	(0.7)	0.1	(1.1)
Loss on extinguishment of debt		(35.9)		(35.9)
All other, net	(1.7)	0.4	(1.5)	0.6
Other expense, net	$ (3.7)	$ (36.6)	$ (5.3)	$ (37.0)