INVENTORIES (Inventories) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012
INVENTORIES [Abstract]
Finished products	$ 270,603	[1]	$ 262,886	[1]
Raw materials	29,996		27,758
Products in process	6,613		5,963
Operating supplies and other	37,394		38,415
Total	344,606		335,022
Encumbered Inventory	$ 4,492		$ 8,726

[1] Includes inventories encumbered by the purchaser's percentage of volumetric production payments (see Note 1, Deferred Revenue), as follows: December 31, 2013 — $4,492 thousand and December 31, 2012 — $8,726 thousand.