INVENTORIES (Inventories) (Details) - USD ($) $ in Millions		Dec. 31, 2021	Dec. 31, 2020
INVENTORIES [Abstract]
Finished products	[1]	$ 418.0	$ 378.4
Raw materials		59.9	33.8
Products in process		4.2	4.5
Operating supplies and other		39.2	31.9
Inventories		521.3	448.6
Encumbered inventories		$ 2.8	$ 2.4

[1] Includes inventories encumbered by volumetric production payments (see Note 2), as follows: December 31, 2021 — $2.8 million and December 31, 2020 — $2.4 million.