Consolidated Statements of Net Income (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 27, 2014		Dec. 28, 2013		Dec. 29, 2012
Net sales	$ 851,995		$ 757,853		$ 667,913
Cost of sales	527,567		461,621		409,446
Gross profit	324,428		296,232		258,467
Selling, general and administrative expenses	146,975		132,657		124,277
Research and development expenses	31,122		24,415		21,231
Amortization of intangibles	12,501		9,279		6,089
Total operating expenses	190,598		166,351		151,597
Operating income	133,830		129,881		106,870
Interest expense	4,903		2,917		1,701
Impairment and equity in net loss of unconsolidated affiliate		[1]	10,678	[1]	7,334	[1]
Foreign exchange loss (gain)	3,925		(3,303)		3,179
Other expense (income), net	(6,644)		(4,646)		(5,396)
Income before income taxes	131,646		124,235		100,052
Income taxes	32,228		35,451		24,720
Net income	$ 99,418		$ 88,784		$ 75,332
Basic (in Dollars per share)	$ 4.41		$ 3.98		$ 3.45
Diluted (in Dollars per share)	$ 4.37		$ 3.94		$ 3.40
Basic (in Shares)	22,543		22,315		21,822
Diluted (in Shares)	22,727		22,537		22,098

[1] During the first quarter of 2013, the company recorded approximately $10.7 million related to the impairment of Shocking Technologies. During the fourth quarter of 2012, the company recorded approximately $7.3 million related to the impairment and equity in net loss of its investment in Shocking Technologies (See Note 6).