Inventories - Summary of Inventories (Details) - USD ($) $ in Millions		Sep. 30, 2025	Dec. 31, 2024
Inventories
Raw materials		$ 75.2	$ 75.0
Work in process		104.2	97.5
Finished goods		220.7	243.8
Total Inventories		400.1	416.3
Titled Inventory
Inventories
Raw materials		60.2	45.3
Work in process		76.1	63.8
Finished goods		168.0	160.3
Total Inventories		304.3	269.4
Supply & Offtake Agreements
Inventories
Raw materials	[1]	15.0	29.7
Work in process	[1]	28.1	33.7
Finished goods	[1]	52.7	83.5
Total Inventories	[1]	$ 95.8	$ 146.9

[1] Amounts represent LIFO value and do not necessarily represent the value at which the inventory was sold. Refer to Note 6 — “Inventory Financing Agreements” for further information.