CONSOLIDATED STATEMENTS OF OPERATIONS (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Statement [Abstract]
Net sales	$ 535,829	$ 397,969	$ 378,924
Cost of sales	420,851	312,744	301,117
Gross profit	114,978	85,225	77,807
Selling, product development and administrative expenses	80,930	56,512	57,239
Gain on sale of product line	0	0	(810)
Operating income	34,048	28,713	21,378
Interest expense	1,093	304	365
Other (income) expense, net	(701)	67	31
Income before income taxes	33,656	28,342	20,982
Income tax expense	11,809	9,187	4,176
Net income	$ 21,847	$ 19,155	$ 16,806
Earnings per common share:
Basic (in usd per share)	$ 1.31	$ 1.16	$ 1.01
Diluted (in usd per share)	$ 1.28	$ 1.14	$ 0.99
Weighted average common shares outstanding	16,662	16,570	16,717
Weighted average common shares and equivalents outstanding	17,003	16,866	16,973