Inventories Inventories (Details) - USD ($) $ in Thousands		Jun. 30, 2016	Dec. 31, 2015
Inventory Disclosure [Abstract]
Finished goods		$ 352,583	$ 264,025
Raw materials and work in process	[1]	114,978	122,038
Stores, supplies and other		49,491	53,450
Total inventories(b)	[2]	$ 517,052	$ 439,513

[1] Includes $44.0 million and $39.1 million at June 30, 2016 and December 31, 2015, respectively, of work in process related to the Lithium product category.

[2] As of June 30, 2016 and December 31, 2015, $69.9 million and $162.8 million, respectively, of inventories were classified as Assets held for sale in the condensed consolidated balance sheets. See Note 3, “Divestitures,” for additional information.