Condensed Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Statement of Comprehensive Income [Abstract]
Net loss	$ (28.3)	$ (40.9)
Other comprehensive income (loss), net of tax:
Foreign currency translation loss	0.0	(2.6)
Defined benefit plans:
Net gain arising from remeasurement during the period, net of tax of $0.4	1.2	0.0
Amortization of prior service benefits included in loss from continuing operations, net of tax of ($0.1), ($0.1)	(0.1)	(0.1)
Amortization of net actuarial gain included in loss from continuing operations, net of tax of ($0.3), ($0.2)	(0.9)	(0.7)
Settlement gains reclassified to loss from continuing operations, net of tax of ($0.2)	(0.8)	0.0
Total other comprehensive loss	(0.6)	(3.4)
Total comprehensive loss	$ (28.9)	$ (44.3)