Consolidated Statements of Net Income (unaudited) - USD ($) shares in Thousands, $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 27, 2015	Jun. 28, 2014	Jun. 27, 2015	Jun. 28, 2014
Net Sales	[1]	$ 222,021	$ 220,908	$ 432,334	$ 427,767
Cost of sales		136,740	137,913	270,723	266,278
Gross profit		85,281	82,995	161,611	161,489
Selling, general and administrative expenses		38,772	38,328	75,117	72,499
Research and development expenses		7,361	7,810	14,745	15,384
Amortization of intangibles		2,977	3,138	6,030	6,297
		49,110	49,276	95,892	94,180
Operating income		36,171	33,719	65,719	67,309
Interest expense		948	1,228	2,099	2,444
Foreign exchange (gain) loss		(1,292)	2,375	1,825	2,123
Other (income) expense, net		(1,202)	(1,446)	(2,328)	(2,632)
Income before income taxes		37,717	31,562	64,123	65,374
Income taxes		9,033	6,984	15,444	15,407
Net income		$ 28,684	$ 24,578	$ 48,679	$ 49,967
Net income per share (see Note 7):
Basic (in dollars per share)		$ 1.26	$ 1.09	$ 2.15	$ 2.22
Diluted (in dollars per share)		$ 1.26	$ 1.08	$ 2.13	$ 2.20
Weighted average shares and equivalent shares outstanding:
Basic (in shares)		22,691	22,579	22,645	22,536
Diluted (in shares)		22,835	22,750	22,810	22,738
Cash dividends paid per common share (in dollars per share)		$ 0.25	$ 0.22	$ 0.50	$ 0.44

[1] Sales by country represent sales to customer or distributor locations.