Condensed Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Statement of Comprehensive Income [Abstract]
Net loss	$ (34.3)	$ (10.1)	$ (75.2)	$ (80.0)
Other comprehensive (loss) income, net of tax:
Foreign currency translation (loss) gain	(1.0)	2.4	(3.6)	2.4
Defined benefit plans:
Net loss arising from remeasurement during the period, net of tax of ($0.9), ($0.9)	(2.8)	0.0	(2.8)	0.0
Amortization of prior service benefits included in net income, net of tax of $0.0, $0.0, ($0.1), ($0.1)	(0.2)	(0.2)	(0.3)	(0.3)
Amortization of net actuarial gain included in net income, net of tax of ($0.3), ($0.4), ($0.5), ($0.6)	(0.8)	(1.0)	(1.5)	(1.8)
Reclassification adjustment for pension settlement benefits included in net income, net of tax of ($0.1), ($0.1)	(0.3)	0.0	(0.3)	0.0
Total other comprehensive (loss) income	(5.1)	1.2	(8.5)	0.3
Total comprehensive loss	$ (39.4)	$ (8.9)	$ (83.7)	$ (79.7)