Inventories

3 Months Ended

Mar. 31, 2018

Inventory Disclosure [Abstract]

Inventories

2. Inventories

At March 31, 2018, and December 31, 2017, approximately 42% of the inventories were valued on the LIFO method with the remaining inventories valued on the FIFO method. Inventories were comprised of the following:

	March 31, 2018		December 31, 2017
Raw materials	$	24,106	$	24,249
Work-in-process		46,987		42,840
Finished goods		28,542		24,083
Supplies		18,545		16,389
Inventories	$	118,180	$	107,561