Summary of Significant Accounting Policies (Inventories) (Details) - USD ($) $ in Millions		Dec. 31, 2019	Dec. 31, 2018
Inventories
Raw materials		$ 59.9	$ 52.4
Work in process		64.1	58.9
Finished goods		168.6	172.8
Inventories total		292.6	284.1
Titled Inventory
Inventories
Raw materials		48.3	30.2
Work in process		35.0	39.7
Finished goods		124.8	128.9
Inventories total		208.1	198.8
Supply & Offtake Agreements
Inventories
Raw materials	[1]	11.6	22.2
Work in process	[1]	29.1	19.2
Finished goods	[1]	43.8	43.9
Inventories total	[1]	$ 84.5	$ 85.3

[1] Amounts represent LIFO value and do not necessarily represent the value at which the inventory was sold. Please read Note 9 - “Inventory Financing Agreements” for further information.