CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Income Statement [Abstract]
Net sales	$ 155,725	$ 131,240	$ 422,660	$ 393,107
Cost of sales	117,532	99,549	316,100	299,827
Gross profit	38,193	31,691	106,560	93,280
Selling, product development and administrative expenses	19,896	16,850	59,062	51,332
Operating income	18,297	14,841	47,498	41,948
Gain on sale of business			0	(18,647)
Interest expense	389	187	643	595
Other income, net	(218)	(150)	(884)	(619)
Income before income taxes	18,126	14,804	47,739	60,619
Income tax expense	5,392	3,618	15,023	19,679
Income from equity method investment	(51)	0	(51)	0
Net income	$ 12,785	$ 11,186	$ 32,767	$ 40,940
Earnings per share:
Basic (in dollars per share)	$ 0.76	$ 0.67	$ 1.94	$ 2.45
Diluted (in dollars per share)	$ 0.75	$ 0.66	$ 1.92	$ 2.40
Weighted average number of common shares outstanding:
Basic (shares)	16,888	16,715	16,859	16,744
Diluted (shares)	17,138	17,028	17,084	17,085