Inventories (Tables)

3 Months Ended

Mar. 31, 2018

Inventory Disclosure [Abstract]

Breakdown of Inventories

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

	March 31,		December 31,
	2018		2017
Finished goods(a)	$	453,662	$	404,239
Raw materials and work in process(b)	154,679		132,891
Stores, supplies and other	58,226		55,651
Total(c)	$	666,567	$	592,781

(a) Increase primarily due to the build up of inventory in our Catalysts segment due to the timing of net sales expected in the second quarter, and an increased net sales in the near term for our Lithium segment.

(b) Increase primarily due to higher forecasted production levels in the second quarter from our Catalysts segment. Included $66.2 million and $59.6 million at March 31, 2018 and December 31, 2017, respectively, of work in process related to the Lithium product category.

(c) As of March 31, 2018 and December 31, 2017, $23.0 million and $24.7 million, respectively, of Inventories were classified as Assets held for sale in the condensed consolidated balance sheets. See Note 2, “Divestitures,” for additional information.