Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Net loss	$ (2,139.8)	$ (616.2)	$ (545.7)
Other comprehensive (loss) income, net of tax:
Pension, SERP and Retiree medical adjustments, net of tax	1.5	70.8	(121.4)
Unrealized foreign exchange gain (loss) on intercompany loan, net of effect	(0.6)	1.8	(4.4)
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax	2.1	9.8	(23.7)
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, after Tax	(3.6)	(0.5)	18.7
Foreign currency translation adjustments	(9.9)	32.4	(49.4)
Total other comprehensive (loss) income, net of tax	(10.5)	114.3	(180.2)
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest		(0.1)	0.5
Total comprehensive loss	$ (2,150.3)	$ (501.9)	$ (725.9)