2. Inventories

Inventories are valued at the lower of cost and net realizable value. Cost is determined using the first‑in, first‑out inventory method. The inventory balance, which includes material, labor and manufacturing overhead costs, is recorded net of an allowance for obsolete or slow-moving inventory.

The components of inventories were as follows:


(in thousands)	March 31,		December 31,
	2017		2016

Raw materials and supplies	$	49,743	$	55,424
Work-in-process		25,371		21,558
Finished goods		239,041		246,307
Inventories	$	314,155	$	323,289