Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 25, 2016	Jun. 27, 2015	Jun. 25, 2016	Jun. 27, 2015
Income Statement [Abstract]
Net sales	$ 209,573	$ 198,721	$ 417,721	$ 387,195
Cost of goods sold	127,409	122,151	254,963	237,732
Gross profit	82,164	76,570	162,758	149,463
Selling, general and administrative expenses	41,175	39,675	82,838	78,916
Income from operations	40,989	36,895	79,920	70,547
Interest expense, net	62	52	119	104
Income before income taxes	40,927	36,843	79,801	70,443
Provision for income taxes	14,945	13,700	29,148	25,961
Net income	$ 25,982	$ 23,143	$ 50,653	$ 44,482
Earnings Per Share:
Basic	$ 0.75	$ 0.65	$ 1.46	$ 1.25
Diluted	$ 0.75	$ 0.65	$ 1.46	$ 1.25
Weighted Average Shares Outstanding:
Basic	34,546	35,548	34,615	35,545
Diluted	34,626	35,614	34,669	35,629