Inventories

6 Months Ended

Jun. 30, 2018

Inventory Disclosure [Abstract]

Inventories

Inventories:

The following table provides a breakdown of inventories at June 30, 2018 and December 31, 2017 (in thousands):

	June 30,		December 31,
	2018		2017
Finished goods(a)	$	452,958	$	404,239
Raw materials and work in process(b)	156,723		132,891
Stores, supplies and other	55,841		55,651
Total(c)	$	665,522	$	592,781

(a) Increase primarily due to the build up of inventory in our Lithium segment resulting from increased sales, and the timing of net sales expected in the second half of our Catalysts segment.

(b) Increase primarily due to higher forecasted production levels in the third quarter from our Catalysts segment. Included $67.0 million and $59.6 million at June 30, 2018 and December 31, 2017, respectively, of work in process related to the Lithium product category.

(c) As of December 31, 2017, $24.7 million of Inventories were classified as Assets held for sale in the condensed consolidated balance sheets. See Note 2, “Divestitures,” for additional information.