Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 33.7	$ (0.6)	$ 15.9
Other comprehensive income (loss):
Foreign currency translation adjustments	2.1	(7.7)	(2.1)
Change in unrecognized pension and postretirement benefit costs	0.0	0.0	3.1
Other comprehensive income (loss)	2.1	(7.7)	1.0
Comprehensive (income) loss attributable to noncontrolling interest	(0.3)	0.5	0.0
Comprehensive income (loss) attributable to controlling interest	$ 35.5	$ (7.8)	$ 16.9