Inventories (Tables)

12 Months Ended

Dec. 31, 2017

Inventory Disclosure [Abstract]

Summary of Inventories

Inventories (at LIFO value) consist of the following as of December 31 (in thousands):

	2017			2016
Finished goods	$	32,986		$	29,686
Raw materials		19,432			20,231
Total FIFO (first-in, first out) inventories		52,418			49,917
Reserve to adjust inventories to LIFO value		(20,070	)		(21,371	)
Total LIFO inventories	$	32,348		$	28,546