Summary of Significant Accounting Policies - Inventories (Details) - USD ($) $ in Millions		Dec. 31, 2024	Dec. 31, 2023
Inventories
Raw materials		$ 75.0	$ 89.2
Work in process		97.5	109.0
Finished goods		243.8	241.2
Total Inventories		416.3	439.4
Titled Inventory
Inventories
Raw materials		45.3	61.6
Work in process		63.8	72.3
Finished goods		160.3	162.1
Total Inventories		269.4	296.0
Supply & Offtake Agreements
Inventories
Raw materials	[1]	29.7	27.6
Work in process	[1]	33.7	36.7
Finished goods	[1]	83.5	79.1
Total Inventories	[1]	$ 146.9	$ 143.4

[1] Amounts represent LIFO value and do not necessarily represent the value at which the inventory was sold. Please read Note 7 — “Inventory Financing Agreements” for further information.