CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS)
Net income (loss)	$ (222.0)	$ 48.1	$ (173.3)
Other comprehensive income:
Defined benefit pension and retiree health benefit plans	0.2	1.1	1.8
Total other comprehensive income	0.2	1.1	1.8
Comprehensive income (loss) attributable to stockholders' equity / partners' capital (deficit)	$ (221.8)	$ 49.2	$ (171.5)