Consolidated Statements of Earnings (Loss) - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Net Sales
Net sales	$ 396,679	$ 382,310	$ 404,021
Cost of goods sold	256,251	255,201	274,058
Gross Margin	140,428	127,109	129,963
Selling, general and administrative expenses	61,624	59,586	61,051
Research and development expenses	24,040	22,461	22,563
Non-recurring environmental expense	0	14,541	0
Restructuring and impairment char	3,048	14,564	5,941
Gain (Loss) on Disposition of Property Plant Equipment	(11,450)	(2,156)	(1,915)
Operating earnings	63,166	18,113	42,323
Other (expense) income:
Interest expense	(3,702)	(2,628)	(2,326)
Interest income	1,305	3,073	2,786
Other expense	(3,524)	(6,297)	(3,435)
Total other expense, net	(5,921)	(5,852)	(2,975)
Earnings before taxes	57,245	12,261	39,348
Income tax expense	22,865	5,307	12,826
Net earnings	$ 34,380	$ 6,954	$ 26,522
Basic
Net earnings (loss) per share (usd per share)	$ 1.05	$ 0.21	$ 0.79
Diluted
Diluted net earnings (loss) per share (usd per share)	$ 1.03	$ 0.21	$ 0.78
Basic weighted-average common shares outstanding (in shares)	32,728	32,959	33,618
Effect of dilutive securities (in shares)	523	525	512
Diluted weighted - average common shares outstanding (in shares)	33,251	33,484	34,130
Cash dividends declared per share (in dollars per share)	$ 0.16	$ 0.160	$ 0.160