Unrestricted Subsidiaries - Income Statement Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Schedule of Equity Method Investments
Sales	$ 993.9	$ 1,005.8
Cost of sales	1,075.3	927.3
Gross profit (loss)	(81.4)	78.5
Operating costs and expenses:
General and administrative	12.1	23.3
Other operating expense	5.1	5.2
Operating income (loss)	(48.7)	36.3
Other income (expense):
Interest expense	(58.5)	(60.8)
Loss on derivative instruments	(7.2)	(16.9)
Other income	0.4	0.2
Total other expense	(112.9)	(77.7)
Net loss	(162.0)	(41.6)
Unrestricted Subsidiaries
Schedule of Equity Method Investments
Sales	165.6	150.3
Cost of sales	192.1	184.0
Gross profit (loss)	(26.5)	(33.7)
Operating costs and expenses:
General and administrative	9.7	6.5
Other operating expense	1.5	1.5
Operating income (loss)	(37.7)	(41.7)
Other income (expense):
Interest expense	(24.8)	(24.6)
Loss on derivative instruments	(5.6)	2.4
Debt extinguishment costs	(47.6)
Other income	0.8	0.3
Total other expense	(77.2)	(21.9)
Net loss	$ (114.9)	$ (63.6)